Ann Nutr Metab 1991 ;35(suppl 1):41—52
© 1991 S. Karger AG, Basel 0250-6807/91/0357-0041$2.75/0
Health Status in Finland and Other Nordic Countries with Special Reference to Chronic Non-Communicable Diseases Jaakko Tuomilehto Department of Epidemiology. National Public Health Institute, Helsinki, Finland
Key Words. Health patterns • Nordic countries • Non-communicable diseases • Infant mortality • Insulin-dependent diabetes mellitus • Cardiovascular diseases • Cancer Abstract. It is a general belief that the health status of the populations of the Nordic Countries, Denmark, Finland, Iceland, Norway and Sweden is very good. Infant mortality is the lowest in these countries. However, other indicators of the health status such as overall life expectancy and incidence of mortality from chronic non-communicable diseases demon strate a large variation between the Nordic countries. Compared with other countries fre quency of several non-communicable diseases is among the highest worldwide. Moreover, the incidence and mortality trends in non-communicable diseases suggest a heterogeneous development among the Nordic countries.
The health situation in the Nordic coun tries, Denmark, Finland. Iceland. Norway and Sweden, is often considered good, even excellent today. Control of infectious dis eases has been successfully carried out dur ing the past decades and the infant mortality is the lowest worldwide in these countries. The major health problems are related to chronic noncommunicable diseases and the life-style of these populations. In this epidemiological review of the cur rent health situation and past trends in mor bidity and mortality we have selected de-
scriptive characteristics of disease rates and some environmental determinants of noncommunicable diseases in the Nordic coun tries. The main emphasis is on the potential role of diet in the variation of the major noncommunicable diseases and their risk fac tors.
Materials and Methods The data prevented here are collected from many different sources. Due to the differences in data col lection and analytical methods between studies and countries it may not be easy to draw conclusive infer ence from such a variety of data. The primary aim of
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Introduction
the present report is to demonstrate specific features of geographic variation and changes over time. Denmark, Finland, Iceland, Norway and Sweden are located in Northern Europe but only a small pro portion of their population lives north of the arctic circle. Sweden has the largest area, 487,000 km2, and population, 8.3 million inhabitants. The population of Iceland is the smallest. 230.000 in 1980. Between 1950 and 1980 the population in all the Nordic countries grew by approximately 20%, but in Iceland, the increase was about 50%. In 1980, the population density was highest in Denmark. 119 persons/km2, and lowest in Iceland. 2 persons/km2. There are very large variations in the population den sity within the largest countries, Finland, Norway and Sweden. In the south and close to all capital cities the population density approaches the Danish average, whereas the northernmost parts of these three coun tries, the population density is comparable with the average in Iceland. Compared with many other countries, the Nordic countries have a very high availability of medical ser vices. During the past 3 decades the density of these services, measured in various ways, has increased 2to 4-fold. In 1980 there were about 75 persons for each hospital bed in Finland. 90 in Iceland, 125 in Denmark and Sweden, and 140 in Norway [1], In the five Nordic countries there were about 500 persons per physician in 1980. In all Nordic countries there is a population-based cancer registry. The Danish Cancer Registry is the oldest, founded in 1942. The Norwegian, Finnish and Icelandic registries have been working since 19521954, and the Swedish Cancer Registry since 1958. In every Nordic country the aim has been routinely to collect a minimum data set in each centralized registry, which could then be supplemented for special studies, but the data are collected in different forms [2], Trends in cardiovascular diseases can be rela tively accurately assessed using mortality statistics in the Nordic countries which have reliable death certif ication and relatively high autopsy rates. Denmark. Finland and Sweden took part in the first WHO Heart Attack Register [3] and Stroke Register [4] studies, and in addition to these three Iceland is also partici pating in the currently ongoing WHO MONICA pro ject [5, 6]. Data on cardiovascular risk factors have been collected in many surveys of these countries. In Finland, four cross-sectional population surveys (in 1972. 1977, 1982 and 1987) for assessing the levels of
Tuomilehto
coronary heart disease risk factors have been carried out in North Karelia and in the province of Kuopio, another province in eastern Finland. In 1982 and 1987 a survey was carried out also in a third area in southwestern Finland [7. 8]. The incidence of insulin-dependent diabetes mellitus (1DDM) in childhood has been determined in all Nordic countries, except Iceland. Since 1986. the DERI group [9. 10] has collected standardized inci dence data from recognized IDDM registries world wide. Data on non-insulin-dependent diabetes mellitus (NIDDM) are less adequate. However, compara ble national statistics of the consumption of oral antidiabetic drugs are available [11]. Monitoring o f Risk Factor Levels The risk factor levels and dietary habits have been studied by population surveys carried out at 5-year intervals since 1972 in North Karelia and the neigh boring Kuopio province which was used as the refer ence area [7, 12, 13]. Each survey dealt with crosssectional, independent, representative population samples from these two areas. The samples included 6.6% of men and women aged 25-59 years in 1972 and 30-64 years in 1977. Both in 1982 and 1987 the sample was drawn from the age group 25-64 years and was stratified for each sex and 10-year age group to fit the protocol of the international MONICA pro ject. The surveys included a self-administered ques tionnaire filled in at home and measurements of height, weight, and blood pressure at the examination site. A venous blood sample was taken for determina tion of serum cholesterol concentration. Each survey questionnaire had also multiple choice questions about dietary habits [12]. In 1982, a dietary survey using food records was also carried out in a subsample [14]. Most of these were qualitative or frequency questions but the consumption of milk, coffee, tea. and bread as well as the amount of fat spread used on bread were assessed quantitatively. Total fat and sat urated fatty acids derived from milk and fat used on bread were calculated and used as a rough indicator of fat intake. The baseline survey of the Salt project was carried out separately in 1979 but the follow-up was part of FINMONICA both in 1982 and 1987 when salt in take was assessed in a subsample of the survey partic ipants [15]. In all these three surveys. 24-hour urine collections were used for the measurement of Na and K intake in the population.
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43
Health Patterns in the Nordic Countries
Results Mortality and Incidence The infant mortality rates in the Nordic countries are the lowest in the world. In 1981 the proportion of babies who died before the age of I year was between 0.7 and 0.8% in all the Nordic countries. The lowering of infant mortality has been one of the major factors causing an increase in life expectancy. Dur ing the past 15 years the declining trend in infant mortality was similar in these five countries: mortality is now one third of that in 1960 (table 1). In 1951-1955 the life ex pectancy for males was 63 years in Finland and 70-71 years in the other Nordic coun tries. In 1980 the life expectancy for Finnish males was 69 years and for the other Nordic countries between 71 and 74 years (highest
.
Table 1 Infant mortality (per 1,000 live births) in the Nordic countries Country
I960
1970
1980
1986
Denmark Finland Iceland Norway Sweden
21.5 21.0 13.0 18.9 16.6
14.2 13.2 13.2 12.7 11.0
8.4 7.6 7.7 8.1 6.9
8.2 5.9 5.4 7.9 5.9
in Iceland). For females the life expectancy was 70 years in Finland and between 73 and 75 years in the other Nordic countries in 1951-1955. In 1980 the Finnish women had reached the level of the life expectancy in the other Nordic countries, i.e. 77-80 years (highest in Iceland) (table 2). The main chronic disease among children in the Nordic countries is IDDM. The high est average annual incidence of IDDM has been reported from Finland (table 3), but also other Nordic countries rank high inter nationally. The lowest IDDM incidence within Europe has been found in Poland, about one sixth of that in Finland [9, 10]. The incidence has increased in the Nordic countries, for instance in Finland it has tri pled during the past 30 years [16]. The rea sons for this high incidence and the temporal trend in IDDM in northern Europe are not known. In the middle-aged population the major causes of morbidity and mortality are car diovascular diseases (CVD), cancer, traffic accidents and suicides. The frequency of these largely vary between and even within the Nordic countries. Finland is known for its extraordinarily high mortality from CVD. Compared with other Nordic countries, however, accidents
Table 2. Mean life expectancy (years) at different ages in the Nordic countries in 1984
Denmark Finland Iceland Norway Sweden
At 40 years
At 0 years
At 65 years
men
women
men
women
men
women
71.8 70.4 74.9 73.0 73.9
77.8 78.8 80.6 79.8 80.1
29.6 28.4 32.5 30.6 31.3
34.7 35.3 37.1 36.5 36.6
14.0 13.3 16.1 14.5 14.9
18.0 17.5 19.2 18.8 19.4
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Country
44
Tuomilchto
Table 3. Age-adjusted incidence of IDDM in the Nordic countries [modified from 10] Country
Incidence (95% confidence interval)
Study period
Denmark Finland Norway Sweden
1970-1976 1970-1986 1973-1982 1978-1986
males
females
K.5 (n.a.) 30.4(29.4-31.6) 21.4 (20.1-22.7) 23.8 (22.7-24.9)
13.4 (n.a.) 27.1 (26.0-28.2) 19.4(18.2-20.7) 22.5 (21.4-23.6)
n.a. = not available.
Tabic 4. Standardized mortality ratio among men aged 35-44 years in the Nordic countries as compared to Finland (Finland = 100)
All causes Cancer IHD Cerebrovascular disease Traffic accidents Suicides
Sweden
Denmark
Finland
Norway
1970
1984-1985
1970
1984-1985
1970
1984-1985
1970
1984-1985
51 105 34 24 58 71
76 126 56 47 86 82
100 100 100 100 100 100
100 100 100 100 100 100
54 93 66 36 58 71
65 115 34 24 86 82
49 75 22 27 44 80
64 92 45 36 66 59
and suicides are also common in Finland (ta ble 4). In men aged 35-44 years the cause of death which is most evenly distributed among countries is cancer, whereas the between-country differences for CVD were large. During the past 15 years the differ ences in mortality from all causes and from CVD between Finland and other Nordic countries have markedly decreased. Table 5 shows the changes in mortality from all causes and from CVD for the two 15-year periods 1952-1967 and 1970-1985 in people aged 30-69 years. During the first period all causes of mortality in men in creased in Denmark and Norway, but in
women they decreased in all Nordic coun tries. During 1970-1985 all causes of mor tality decreased in all the countries and both sexes (except in Danish males), and the rela tive changes were largest in Iceland and Fin land. Trends in mortality from CVD and ischaemic heart disease (IHD) followed the same pattern: in men, there was a steep increase, during the first period, most pro nounced in Denmark and Norway, whereas during the second period the decrease was most pronounced in Iceland and Finland. The trends in CVD and IHD in women dif fered from those of men: during both periods there was a decline which accelerated over
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Cause of death
Health Patterns in the Nordic Countries
45
Table 5. Percentage change in age-standardized mortality among men and women aged 30-69 years Country
Change per 15 years. % men
women
1952-1967 All causes
All CVD
IHD
Cerebrovascular disease
Denmark Finland Iceland Norway Sweden
9.5 -4 .7
Denmark Finland Iceland Norway Sweden
21.2 8.6
-
13.6 -2 .9
-
49.7 2.0
Denmark Finland Iceland Norway Sweden
60.8 23.8
Denmark Finland Iceland Norway Sweden
-29.7 -4.7
-
98.6 32.0
-
10.2 -33.5
time and was especially steep in Finnish women. Stroke mortality decreased in all countries and during both periods (except in Norwegian men during 1952-1967). During 1970-1985 the declines in stroke mortality were rather similar in men and women, and they were considerable for Iceland and Fin land. However, it is important to note that stroke mortality in Finland did not decrease during the 1980s anymore [17], It was put forward that only about half of all cases of IDMM in the population have the onset before the age of 15 years [18]. Recent data from Sweden [19] suggest that in the age group 15-34 years 78% of new
1970-1985
1952-1967
1970-1985
0.5 -25.0 -28.9 -11.9 -8.3
-15.3 -25.6
-4.1 -32.4 -37.7 -15.2 -19.4
-9.7 -27.5 -35.0 -16.6 -6.4
-23.7 -23.4
-
-17.3 -28.0
-
-15.3 -38.0
-24.1 -45.6 -30.1 -33.5 -30.3
-8.0 -23.0 -23.6 -13.6 -2.5
16.4 -7.5 27.2 -9 .9
-20.9 -31.1 -19.8 -23.3 -25.3
-17.2 -35.2 -48.0 -39.2 -26.3
-56.5 -28.5 -30.8 -54.4
-23.8 -50.1 -60.5 -43.5 -40.8
-
cases of diabetes were IDDM and 15% NIDDM. In older age groups the main type of diabetes is NIDDM, the frequency of which can be best assessed by prevalence studies [20]. Standardized survey methods and criteria for diabetes were not available before the WHO Expert Committee report in 1980 [21]. This may be one of the reasons why comparative prevalence data on NIDDM are not available in the Nordic countries. The best estimates from the existing reports suggest that the prevalence of ‘known dia betes' among population aged 30 years and above varies between 3 and 5% [11]. The
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Cause of death
Tuomilehto
Table 6. Estimated consumption of insulin and oral antidiabetic drugs (defined daily dose/1.000 inhabitants/day) in the Nordic countries in 1976 and 1986 based on the sales statistics [from 11] Country
1976 Denmark Finland Iceland Norway Sweden
Oral antidiabetics
Insulin
4.0 6.0 1.5 4.0 8.2
1986 6.4 6.7 3.2 5.6 10.8
1976
1986
4.3 11.9 2.1 5.0
6.0 13.5 3.5 5.4 10.8
11.0
proportion of diabetics over 30 years of age is about 2-3% in the Nordic countries. The recent study in Finland using the WHO sur vey criteria gave a prevalence of NIDDM of 5.7% in men and 4.6% in women aged 4564 years [Tuomilehto, unpubl. data]. In the elderly population of Finland the prevalence of diabetes was found to be high [22], The sales statistics of antidiabetic drugs show an overall increase in drug use, both insulin and oral antidiabetic drugs (table 6). These data also suggest that both IDDM and NIDDM are more common in Finland and Sweden than in the other Nordic countries. The incidence of cancer has slowly in creased in both sexes in all Nordic countries [2], Until 1973 Finland had the highest can cer incidence in men. but now Denmark is ranking first for both sexes (table 7). In wom en, Finland has clearly lower incidence than other Nordic countries. Internationally, the Nordic countries are in the middle of the list of 80 countries for which data are available. The change in cancer incidence in Finland has been less steep than in other Nordic countries. In men aged less than 60 years the incidence did not increase at all due to the
levelling off of the increasing trend in lung cancer in Finnish men around 1970. In the 1950s there was a 5.5-fold differ ence in lung cancer mortality between the highest (Finland) and lowest (Norway) inci dence, but in 1978-1980 the range was re duced to 2.8-fold. In women, lung cancer incidence has increased in all Nordic coun tries and the differences between countries have also increased. Iceland and Denmark had all the time about 2.5 times higher rates than the others. Breast cancer incidence is lowest in Finland, but the between-country difference has become smaller. Stomach can cer incidence had steadily decreased in all Nordic countries, but is still relatively high in Iceland and Finland. The 2.5-fold differ ence between the highest (Denmark) and the lowest (Finland) colon cancer rate in the early 1960s has now diminished to about 2.0. The incidence of colon cancer has in creased in both sexes in all Nordic countries, more steeply in Finland than elsewhere. Risk Factor Trends in North Karelia, Finland The reductions of all major coronary risk factors, smoking, blood pressure, and serum cholesterol were most remarkable in the province of North Karelia during 1972 to 1977 [23], Thereafter, changes were modest except for smoking in men, and the differ ences between North Karelia and the neigh boring province almost disappeared. During 1972 to 1987, the mean serum cholesterol in men decreased 0.86 mmol/1 in North Karelia [8], In 1972. in North Karelia 24.3% of men and 22.4% of women had both high choles terol and high blood pressure, but by 1982 the proportion of such high-risk subjects had fallen to about 10% [23]. These surveys sug gest that the P:S ratio of North Karelians
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Health Patterns in the Nordic Countries
Table 7. Age-adjusted incidence per 100,000 of cancer of selected sites in the Nordic countries in two time periods by sex [modified from 2] Men
Women
1956-1960
1976-1980
change. %
1955-1960
1976-1980
change, %
199 232 202 169 173
263 258 231 228 229
32 11 14 35 32
214 159 187 161 187
242 175 230 206 213
13 10 23 28 14
Lung cancer Denmark Finland Iceland' Norway Sweden2
29 60 12 12 15
56 75 27 28 26
93 25 125 133 73
5 4 6 3 4
15 7 20 6 7
200 75 233 100 75
Prostate/breast3 Denmark Finland Iceland' Norway Sweden2
19 17 17 26 27
28 33 34 40 45
47 94 100 54 67
45 27 36 38 45
62 43 58 50 58
38 59 61 32 29
30 14 16 15 18
19 6 9 17 10
-3 7 -5 7 -4 4 13 -4 4
All sites Denmark Finland Iceland Norway Sweden-
Cervix uteri Denmark Finland Iceland' Norway Sweden2 Stomach Denmark Finland Iceland' Norway Sweden2
29 56 72 36 28
15 25 29 19 16
-4 8 -5 5 -6 0 47 -4 3
18 32 31 21 14
7 13 14 10 8
-61 -5 9 -5 5 -5 2 -4 3
Colon Denmark Finland4 Iceland' Norway Sweden2
14 7 9 10 13
21 10 15 17 16
50 43 67 70 23
17 8 10 10 13
20 10 13 17 15
18 25 30 70 15
1 2 3 4
The first period in Iceland was 1955-1960. The first period in Sweden was 1958-1960. In the case of men prostate, in the case of women breast. The first period for colon cancer in Finland was 1961-1965.
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Cancer site Country
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48
Table 8. Mean values of selected characteristics of male current non-smokers and smokers in Finland in 1982 and 1987 [from 25] 1982
Alcohol consumption1, g/week Saturated fat intake2, g/day Leisure time exercise3 Education, years Resting heart rate, beats/min Age, years Cigarettes smoked daily
1987
non-smokers (n = 2,779)
smokers (n = 1,729)
non-smokers (n = 1,911)
smokers (n = 1,002)
46.0 28.2 2.01 9.1 69.0 45.2 -
95.3 32.8 1.75 8.8 74.8 42.9 18.2
45.5 24.0 2.00 9.8 70.0 46.1 -
95.8 30.9 1.78 9.4 75.9 43.3 18.3
increased during the early 1970s from 0.20 to 0.28 in urban areas whereas in rural areas the P:S ratio stayed below 0.20 [12, 13]. The FINMONICA dietary survey in 1982 showed that the P:S ratio had stayed at the same level of 0.28 among urban people but there was an increase from 0.15 in 1969-1972 to 0.23 in 1982 among rural people [14]. In North Kar elian men fat provided 38.0% and in women 36.0% of total energy. The available dietary data support the findings for trends in serum cholesterol val ues in the 1970s. The major decrease in the intake of saturated fatty acids took place during 1972 to 1977 parallel with a decline in the serum cholesterol values [12. 13]. The trends in the 1980s seem to be different from those in the 1970s. Serum cholesterol values decreased significantly only in women but not in men during 1982 to 1987. The mean body mass index increased during 1972 to 1982 in eastern Finland in men from 26.0 to 26.5 kg/m2 whereas in
women it decreased from 26.9 to 26.4 kg/m2 [24] , During the 1980s smoking did not de crease further despite major national efforts to control it [23], Interestingly, we found out that smokers in our 1987 survey were not anymore much leaner than non-smokers [25] . Smokers seem to have increasingly a cluster of unhealthy habits (table 8). Blood pressure levels in North Karelia de creased considerably during 1972 to 1977, but no further improvement in the blood pressure control has taken place since the late 1970s [ 17], This observation is in accord with the trends in dietary determinants of blood pressure in Finland: body mass index has increased in men and recently also in women, alcohol consumption has increased, P:S ratio has remained low and salt intake has de creased only modestly. About 12% of the Fin nish population aged 25-64 years are cur rently under antihypertensive drug therapy. The recent comparison of risk factor data between the populations in the WFIO
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1 Self reported alcohol consumption during week preceding surveys. 2 Saturated fat from milk and fat used on bread only (see text for results of analysis of variance). 3 Four-point scale from sedentary to training for competitive endurance sports.
49
Health Patterns in the Nordic Countries
Table 9. Mean values of systolic (syst) and diastolic (diast) blood pressure (mean of two measurements), serum total cholesterol and body mass index (BM1) in the populations from the Nordic countries included in the WHO MONICA project [from 26] Men. mm Hg
Women, mm Hg
Serum cholesterol mmol/1
BM1, kg/m2
syst
diast
syst
diast
men
women
men
women
Finland North Karelia Kuopio Turku/Loimaa
144 147 142
88 90 87
142 146 137
85 86 82
6.4 6.4 6.2
6.3 6.3 6.1
26.9 26.8 26.8
27.1 26.6 25.8
Sweden Northern Sweden Gothenburg
131 n.a.
83 n.a.
128 n.a.
80 n.a.
6.3 6.2
6.2 6.1
26.0 25.3
25.5 24.3
Denmark Glostrup
127
81
124
77
6.3
6.3
23.8
24.4
Iceland
126
83
120
78
6.2
6.3
25.9
25.9
MONICA project [26] have clearly demon strated that the blood pressure levels among Finnish men and women aged 35-64 years are higher than in the other Nordic countries (table 9). Serum cholesterol levels varied only little between the Nordic MONICA centres, but body mass index was clearly higher in Finland than in other centres.
Comments Despite the very low infant mortality and the good availability of health services which are very similar in all five Nordic countries, the disease patterns amongst the middleaged populations vary markedly between these countries. In many ways Finland seems to be the Nordic country with the most unfa vorable health profile for the middle-aged,
especially among men. The trends in the incidence and mortality from CVD and ma jor cancers in the Nordic countries have been more favorable in women than men. Among women the between-country differ ences have rapidly diminished during the past years. This is mainly due to the steep decrease in coronary heart disease and stroke and lesser increase in cancer inci dence in Finland. Many of the non-communicable diseases which are main causes of morbidity and mortality in the Nordic populations are asso ciated with diet. Many of the geographic dif ferences in non-communicable diseases within the Nordic countries are probably largely determined by dietary factors, but data are not sufficient to estimate precisely the relative contribution of different nu trients to the differences in the occurrence of
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n.a. = not available.
diseases. The diet-related risk factors of noncommunicable diseases such as hypercholesterolaemia, hypertension, obesity and glu cose intolerance are more prevalent in Fin land than elsewhere in the Nordic coun tries. There is good evidence that the favorable disease trends in the Nordic countries that have been observed during the past 10-20 years have been associated with the im provement of the diet. However, the role of effective and early case finding of individu als at high risk for various non-communica ble diseases, especially cervical cancer, high blood pressure and hyperglycaemia should not be underestimated. The implementation of both dietary recommendations and pre ventive primary health care services have varied between the Nordic countries. A good example is cancer of the cervix uteri. In Fin land, Iceland and Sweden nationwide mass screening for cervical smear has been orga nized since the mid-1960s with a steep de cline in the incidence after that. In Denmark where only about 40% of women have been screened the decline has been much smaller, and in Norway where only 5% of women are screened the incidence has remained un changed [2], It can be argued that some of these differ ences might be explained by differences in other factors like genetic predisposition which could make the Finns, for instance, more sensitive to the effects of high satu rated fat intake. Actually, it has been shown that a decrease in saturated fats and an increase in the P:S ratio in the diet will effec tively lower serum cholesterol and blood pressure levels in the Finns [27, 28]. On the other hand, the higher prevalence of obesity among the Finns clearly demonstrates that their overall energy intake in relation to the
Tuomilehto
consumption is higher, and because a large proportion of energy is derived from satu rated fats, it is not unexpected that the risk factor levels in Finland are less satisfactory than in the other Nordic countries. One peculiarity in the occurrence of var ious forms of CVD and cancer in the Nordic countries is the large differential in the rates between men and women. Mortality from IHD is more than 6 times higher in men than women in eastern Finland, and elsewhere in the Nordic countries this differential is about 5-fold [5]. This fact also points to wards environmental rather than genetic origin of CVD and cancer. However, geo graphic differences for both types of dia betes, 1DDM and NIDDM, are relatively small. For instance in Finland, the occur rence of most non-communicable diseases shows a large difference between eastern and western Finland, but not for IDDM and NIDDM which are among a few diseases without such a geographic gradient. Both IDDM and NIDDM have a strong genetic susceptibility [29] and, therefore, it can be argued that genetic differences within Fin land are maybe not so large that they would be the major determinants for large geograph ic differences either for CVD or cancer. Some of the disease patterns and changes may be associated with the typical life-style in the Nordic countries. One example is the very high coffee consumption [30. 31], which is highest in the Nordic countries worldwide and which may be partly respon sible for the high levels of serum cholesterol in these countries where it has been custom ary to drink boiled coffee which can raise serum cholesterol [32], It has also been sug gested that coffee may increase the risk of IHD [33] over and above the effect mediated through cholesterol. Recently, it has also
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50
been speculated that high coffee consump tion in the Nordic countries might be associ ated with the extremely high incidence of IDDM in these countries [34], Although the overall population of the Nordic countries is not very large, there are distinct differences both in the genetic back ground and life-style among the populations in these countries. The geographic area cov ered by these countries is relatively large and environmental conditions vary markedly. Traditionally, it has been relatively easy to carry out population-based studies in these countries because all of them have national population registers and well-organized health care systems. Data that have accumu lated about the determinants of non-commu nicable diseases have been used for planning community-based intervention activities, like the North Karelia Project [7, 13, 15, 23], However, there is much variability not only in life-styles but also in implementing health promotion and disease prevention pro grammes among the Nordic countries [35]. The overall health situation in these coun tries is still far from ideal.
References 1 Yearbook of Nordic Statistics 1983. Stockholm. Nordic Council and Nordic Statistical Secretariat. 1984, vol. 22. 2 Hakulinen T. Andersen A, Mahler B. Pukkala E, Schon G. Tulinius H: Trends in cancer incidence in the Nordic Countries. A collaborative study of the five Nordic Cancer Registries. Acta Pathol Microbiol Immunol Scand I986:94(suppl):288. 3 World Health Organization Regional Office for Europe: Myocardial Infarction Community Regis ters. Public Health in Europe, No 5. Copenhagen. 1976. 4 Aho K, Harmsen P. Hatano S, Marquardsen J, Smirnov VE, Strasser T: Cerebrovascular disease
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in the community: Results of a WHO Collabora tive Study. Bull World Health Organ 1980;58: 113-130. 5 Tuomilehto J. Kuulasmaa K, Torppa J: The prin cipal investigators of the MONICA project: WHO MONICA project: Geographic variation in mor tality from cardiovascular diseases - Baseline data on selected population characteristics and cardio vascular mortality. World Health Stat Q 1987; 402: D 1-184. 6 Tuomilehto J. Kuulasmaa K: WHO MONICA Pro ject: Assessing CHD Mortality and Morbidity. Int J Epidemiol 1989; 18(suppl 1):S38—S45. 7 Puska P. Salonen JT. Nissinen A, et al: Change in risk factors for coronary heart disease during 10 years of a community intervention programme (North Karelia Project). Br Med J 1983:287: 1840-1844. 8 Salomaa V, Korhonen HJ, Tuomilehto J, Vartiainen E. Pietinen P. Kartovaara L, Gref C-G, Nissinen A, Puska P: Serum cholesterol distribu tion. measurement frequency and cholesterol awareness in Finland. Eur Heart J 1990:11:294301. 9 Diabetes Epidemiology Research International Group: Geographic patterns of childhood insulindependent diabetes mellitus. Diabetes 1988;37: 1113-1119. 10 Rewers M, LaPorte RE, King H. Tuomilehto J: Trends in the prevalence and incidence of dia betes: Insulin-dependent diabetes mellitus in childhood. World Health Stat Q 1988;4I. 11 Groop P-H. Klaukka T, Reunanen A: Diabeteslakemedel i Norden. Analys av orsaker till variationer i forbruknigen. Publikationer av folkpensionsanstalten ML. Helsingfors 1990. 12 Pietinen P. Nissinen A. Vartiainen E. Tuomilehto J, Uusitalo U, Ketola A, Moisio S, Puska P: Dietary changes in the North Karelia Project (1972-1982). Prev Med 1988:17:183-193. 13 Pietinen P. Vartiainen E, Korhonen HJ. Kartov aara L. Uusitalo U. Tuomilehto J. Puska P: Nutri tion as a component in the community control of cardiovascular disease (the North Karelia Pro ject). Am J Clin Nutr !989;49(suppl 5): 10171024. 14 Pietinen P. Uusitalo U, Vartiainen E, Tuomilehto J: Dietary survey of the FINMONICA project in 1982. Acta Med Scand I988;(suppl 728): 169177.
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Health Patterns in the Nordic Countries
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27 28
29
30
31
32
33
34
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variation in the major risk factors of coronary heart disease in men and women aged 35-64 years. World Health Stat Q 1988:41:115-138. Pietinen P, Huttunen JK: Dietary fat and blood pressure. A review. Eur Heart J 1987;8:9-17. Nissinen A. Pietinen P. Tuomilehto J. Vartiainen E, Puska P: Predictors of blood pressure change in a series of controlled dietary intervention studies. J Human Hypertens 1987:1:167-173. Barnett AH. Eff C, Leslie RDG, Pyke DA: Dia betes in identical twins, a study of 200 pairs. Diabetologia 1981:20:87-93. Tuomilehto J, Tanskanen A, Pietinen P, Aro A, Salonen J, Happonen P. Nissinen A, Puska P: Cof fee consumption is correlated with serum choles terol in middle-aged Finnish men and women. J Epidemiol Community Health 1987:41:237-242. Thelle DS. Heyden S. Fodor JG: Coffee and cho lesterol in epidemiological and experimental stud ies. Atherosclerosis 1987;67:97-103. Aro A, Tuomilehto J, Kostiainen E, Uusitalo U, Pietinen P: Boiled coffee increases serum lowdensity lipoprotein concentration. Metabolism 1987;36:1027-1030. Tverdal A. Stensvold 1. Solvoli K. Foss OP, LundLarsen P. Bjartveit K: Coffee consumption and death from coronary heart disease in middle-aged Norwegian men and women. Br Med J 1990:300: 566-569. Tuomilehto J, Tuomilehto-Wolf E. Virtala E. LaPorte R: Coffee consumption as trigger for insulin dependent diabetes mellitus in childhood. Br Med J 1990:300:642-643. Haglund B. Tillgren P: Implementation strategies in community intervention. A report from a con ference in April 1986 on the role of community analysis and focus groups in community interven tion studies. Scand J Prim Health Care 1988 (suppl 1):7—129.
Prof. Jaakko Tuomilehto Department of Epidemiology National Public Health Institute Elimaenkatu 25 A 6th floor SF-00510 Helsinki (Finland)
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15 Tuomilehto J. Pietinen P, Uusitalo U, Korhonen H, Nissinen A: Changes in sodium and potassium intake in Finland during the 1980s; in Yamori Y, StrasserT (eds): New Horizons in Preventing Car diovascular Diseases. Amsterdam. Elsevier, 1989, pp 229-239. 16 Reunanen A, Akerblom HK. Tuomilehto J: High incidence of insulin-dependent diabetes mellitus (IDDM) in children in Finland. Arct Med Res 1988;47(suppl l):535-539. 17 Tuomilehto J, Piha T, Nissinen A, Geboers J, Puska P: Trends in stroke mortality and in antihypertensive treatment in Finland from 1972 to 1984 with special reference to North Karelia. J Human Hypertens 1987;1:201-208. 18 Laakso M. Pyorala K: Age of onset and type of diabetes. Diabetes Care 1985:82:114-117. 19 Ostman J. Arnqvist H. Blohme G. et al: Epidemi ology of diabetes mellitus in Sweden. Results of the first year of a prospective study in the popula tion age group 15-34 years. Acta Med Scand 1986;220:437-445. 20 King H. Zimmet P: Trends in the prevalence and incidence of diabetes: Non-insulin dependent dia betes mellitus. World Health Stat Q 1988:41:190— 196. 21 WHO Expert Committee on Diabetes Mellitus: Second report. WHO Tech Rep Ser. 1980, No 646. 22 Tuomilehto J, Nissinen A, Kivela SL. et al: Prev alence of diabetes mellitus in elderly men aged 65 to 84 years in eastern and western Finland. Diabetologia 1986:29:611-615. 23 Tuomilehto J. Puska P, Korhonen H, Mustaniemi H, Vartiainen E, Nissinen A. Kuulasmaa K, Niemensivu H, Salonen J: Trends and determinants of ischaemic heart disease mortality in Finland: With special reference to a possible levelling off in the early 1980s. Ini J Epidemiol 1989; 18(suppl 1): s 109-s 117. 24 Jalkanen L. Tuomilehto J, Nissinen A. Puska P: Changes in body mass index in a Finnish popula tion between 1972 and 1982. J Int Med 1989:226: 163-170. 25 Marti B, Tuomilehto J. Korhonen HJ. Kartovaara L, Vartiainen E, Pietinen P, Puska P: Smoking and leanness: Evidence for change in Finland. Br Med J 1989:298:1287-1290. 26 Pajak A, Tuomilehto J, Kuulasmaa K. Ruokokoski E / The WHO Monica Project: Geographical
© 1991 S. Karger AG, Basel 0250-6807/91/0357-0041$2.75/0
Health Status in Finland and Other Nordic Countries with Special Reference to Chronic Non-Communicable Diseases Jaakko Tuomilehto Department of Epidemiology. National Public Health Institute, Helsinki, Finland
Key Words. Health patterns • Nordic countries • Non-communicable diseases • Infant mortality • Insulin-dependent diabetes mellitus • Cardiovascular diseases • Cancer Abstract. It is a general belief that the health status of the populations of the Nordic Countries, Denmark, Finland, Iceland, Norway and Sweden is very good. Infant mortality is the lowest in these countries. However, other indicators of the health status such as overall life expectancy and incidence of mortality from chronic non-communicable diseases demon strate a large variation between the Nordic countries. Compared with other countries fre quency of several non-communicable diseases is among the highest worldwide. Moreover, the incidence and mortality trends in non-communicable diseases suggest a heterogeneous development among the Nordic countries.
The health situation in the Nordic coun tries, Denmark, Finland. Iceland. Norway and Sweden, is often considered good, even excellent today. Control of infectious dis eases has been successfully carried out dur ing the past decades and the infant mortality is the lowest worldwide in these countries. The major health problems are related to chronic noncommunicable diseases and the life-style of these populations. In this epidemiological review of the cur rent health situation and past trends in mor bidity and mortality we have selected de-
scriptive characteristics of disease rates and some environmental determinants of noncommunicable diseases in the Nordic coun tries. The main emphasis is on the potential role of diet in the variation of the major noncommunicable diseases and their risk fac tors.
Materials and Methods The data prevented here are collected from many different sources. Due to the differences in data col lection and analytical methods between studies and countries it may not be easy to draw conclusive infer ence from such a variety of data. The primary aim of
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Introduction
the present report is to demonstrate specific features of geographic variation and changes over time. Denmark, Finland, Iceland, Norway and Sweden are located in Northern Europe but only a small pro portion of their population lives north of the arctic circle. Sweden has the largest area, 487,000 km2, and population, 8.3 million inhabitants. The population of Iceland is the smallest. 230.000 in 1980. Between 1950 and 1980 the population in all the Nordic countries grew by approximately 20%, but in Iceland, the increase was about 50%. In 1980, the population density was highest in Denmark. 119 persons/km2, and lowest in Iceland. 2 persons/km2. There are very large variations in the population den sity within the largest countries, Finland, Norway and Sweden. In the south and close to all capital cities the population density approaches the Danish average, whereas the northernmost parts of these three coun tries, the population density is comparable with the average in Iceland. Compared with many other countries, the Nordic countries have a very high availability of medical ser vices. During the past 3 decades the density of these services, measured in various ways, has increased 2to 4-fold. In 1980 there were about 75 persons for each hospital bed in Finland. 90 in Iceland, 125 in Denmark and Sweden, and 140 in Norway [1], In the five Nordic countries there were about 500 persons per physician in 1980. In all Nordic countries there is a population-based cancer registry. The Danish Cancer Registry is the oldest, founded in 1942. The Norwegian, Finnish and Icelandic registries have been working since 19521954, and the Swedish Cancer Registry since 1958. In every Nordic country the aim has been routinely to collect a minimum data set in each centralized registry, which could then be supplemented for special studies, but the data are collected in different forms [2], Trends in cardiovascular diseases can be rela tively accurately assessed using mortality statistics in the Nordic countries which have reliable death certif ication and relatively high autopsy rates. Denmark. Finland and Sweden took part in the first WHO Heart Attack Register [3] and Stroke Register [4] studies, and in addition to these three Iceland is also partici pating in the currently ongoing WHO MONICA pro ject [5, 6]. Data on cardiovascular risk factors have been collected in many surveys of these countries. In Finland, four cross-sectional population surveys (in 1972. 1977, 1982 and 1987) for assessing the levels of
Tuomilehto
coronary heart disease risk factors have been carried out in North Karelia and in the province of Kuopio, another province in eastern Finland. In 1982 and 1987 a survey was carried out also in a third area in southwestern Finland [7. 8]. The incidence of insulin-dependent diabetes mellitus (1DDM) in childhood has been determined in all Nordic countries, except Iceland. Since 1986. the DERI group [9. 10] has collected standardized inci dence data from recognized IDDM registries world wide. Data on non-insulin-dependent diabetes mellitus (NIDDM) are less adequate. However, compara ble national statistics of the consumption of oral antidiabetic drugs are available [11]. Monitoring o f Risk Factor Levels The risk factor levels and dietary habits have been studied by population surveys carried out at 5-year intervals since 1972 in North Karelia and the neigh boring Kuopio province which was used as the refer ence area [7, 12, 13]. Each survey dealt with crosssectional, independent, representative population samples from these two areas. The samples included 6.6% of men and women aged 25-59 years in 1972 and 30-64 years in 1977. Both in 1982 and 1987 the sample was drawn from the age group 25-64 years and was stratified for each sex and 10-year age group to fit the protocol of the international MONICA pro ject. The surveys included a self-administered ques tionnaire filled in at home and measurements of height, weight, and blood pressure at the examination site. A venous blood sample was taken for determina tion of serum cholesterol concentration. Each survey questionnaire had also multiple choice questions about dietary habits [12]. In 1982, a dietary survey using food records was also carried out in a subsample [14]. Most of these were qualitative or frequency questions but the consumption of milk, coffee, tea. and bread as well as the amount of fat spread used on bread were assessed quantitatively. Total fat and sat urated fatty acids derived from milk and fat used on bread were calculated and used as a rough indicator of fat intake. The baseline survey of the Salt project was carried out separately in 1979 but the follow-up was part of FINMONICA both in 1982 and 1987 when salt in take was assessed in a subsample of the survey partic ipants [15]. In all these three surveys. 24-hour urine collections were used for the measurement of Na and K intake in the population.
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42
43
Health Patterns in the Nordic Countries
Results Mortality and Incidence The infant mortality rates in the Nordic countries are the lowest in the world. In 1981 the proportion of babies who died before the age of I year was between 0.7 and 0.8% in all the Nordic countries. The lowering of infant mortality has been one of the major factors causing an increase in life expectancy. Dur ing the past 15 years the declining trend in infant mortality was similar in these five countries: mortality is now one third of that in 1960 (table 1). In 1951-1955 the life ex pectancy for males was 63 years in Finland and 70-71 years in the other Nordic coun tries. In 1980 the life expectancy for Finnish males was 69 years and for the other Nordic countries between 71 and 74 years (highest
.
Table 1 Infant mortality (per 1,000 live births) in the Nordic countries Country
I960
1970
1980
1986
Denmark Finland Iceland Norway Sweden
21.5 21.0 13.0 18.9 16.6
14.2 13.2 13.2 12.7 11.0
8.4 7.6 7.7 8.1 6.9
8.2 5.9 5.4 7.9 5.9
in Iceland). For females the life expectancy was 70 years in Finland and between 73 and 75 years in the other Nordic countries in 1951-1955. In 1980 the Finnish women had reached the level of the life expectancy in the other Nordic countries, i.e. 77-80 years (highest in Iceland) (table 2). The main chronic disease among children in the Nordic countries is IDDM. The high est average annual incidence of IDDM has been reported from Finland (table 3), but also other Nordic countries rank high inter nationally. The lowest IDDM incidence within Europe has been found in Poland, about one sixth of that in Finland [9, 10]. The incidence has increased in the Nordic countries, for instance in Finland it has tri pled during the past 30 years [16]. The rea sons for this high incidence and the temporal trend in IDDM in northern Europe are not known. In the middle-aged population the major causes of morbidity and mortality are car diovascular diseases (CVD), cancer, traffic accidents and suicides. The frequency of these largely vary between and even within the Nordic countries. Finland is known for its extraordinarily high mortality from CVD. Compared with other Nordic countries, however, accidents
Table 2. Mean life expectancy (years) at different ages in the Nordic countries in 1984
Denmark Finland Iceland Norway Sweden
At 40 years
At 0 years
At 65 years
men
women
men
women
men
women
71.8 70.4 74.9 73.0 73.9
77.8 78.8 80.6 79.8 80.1
29.6 28.4 32.5 30.6 31.3
34.7 35.3 37.1 36.5 36.6
14.0 13.3 16.1 14.5 14.9
18.0 17.5 19.2 18.8 19.4
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Country
44
Tuomilchto
Table 3. Age-adjusted incidence of IDDM in the Nordic countries [modified from 10] Country
Incidence (95% confidence interval)
Study period
Denmark Finland Norway Sweden
1970-1976 1970-1986 1973-1982 1978-1986
males
females
K.5 (n.a.) 30.4(29.4-31.6) 21.4 (20.1-22.7) 23.8 (22.7-24.9)
13.4 (n.a.) 27.1 (26.0-28.2) 19.4(18.2-20.7) 22.5 (21.4-23.6)
n.a. = not available.
Tabic 4. Standardized mortality ratio among men aged 35-44 years in the Nordic countries as compared to Finland (Finland = 100)
All causes Cancer IHD Cerebrovascular disease Traffic accidents Suicides
Sweden
Denmark
Finland
Norway
1970
1984-1985
1970
1984-1985
1970
1984-1985
1970
1984-1985
51 105 34 24 58 71
76 126 56 47 86 82
100 100 100 100 100 100
100 100 100 100 100 100
54 93 66 36 58 71
65 115 34 24 86 82
49 75 22 27 44 80
64 92 45 36 66 59
and suicides are also common in Finland (ta ble 4). In men aged 35-44 years the cause of death which is most evenly distributed among countries is cancer, whereas the between-country differences for CVD were large. During the past 15 years the differ ences in mortality from all causes and from CVD between Finland and other Nordic countries have markedly decreased. Table 5 shows the changes in mortality from all causes and from CVD for the two 15-year periods 1952-1967 and 1970-1985 in people aged 30-69 years. During the first period all causes of mortality in men in creased in Denmark and Norway, but in
women they decreased in all Nordic coun tries. During 1970-1985 all causes of mor tality decreased in all the countries and both sexes (except in Danish males), and the rela tive changes were largest in Iceland and Fin land. Trends in mortality from CVD and ischaemic heart disease (IHD) followed the same pattern: in men, there was a steep increase, during the first period, most pro nounced in Denmark and Norway, whereas during the second period the decrease was most pronounced in Iceland and Finland. The trends in CVD and IHD in women dif fered from those of men: during both periods there was a decline which accelerated over
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Cause of death
Health Patterns in the Nordic Countries
45
Table 5. Percentage change in age-standardized mortality among men and women aged 30-69 years Country
Change per 15 years. % men
women
1952-1967 All causes
All CVD
IHD
Cerebrovascular disease
Denmark Finland Iceland Norway Sweden
9.5 -4 .7
Denmark Finland Iceland Norway Sweden
21.2 8.6
-
13.6 -2 .9
-
49.7 2.0
Denmark Finland Iceland Norway Sweden
60.8 23.8
Denmark Finland Iceland Norway Sweden
-29.7 -4.7
-
98.6 32.0
-
10.2 -33.5
time and was especially steep in Finnish women. Stroke mortality decreased in all countries and during both periods (except in Norwegian men during 1952-1967). During 1970-1985 the declines in stroke mortality were rather similar in men and women, and they were considerable for Iceland and Fin land. However, it is important to note that stroke mortality in Finland did not decrease during the 1980s anymore [17], It was put forward that only about half of all cases of IDMM in the population have the onset before the age of 15 years [18]. Recent data from Sweden [19] suggest that in the age group 15-34 years 78% of new
1970-1985
1952-1967
1970-1985
0.5 -25.0 -28.9 -11.9 -8.3
-15.3 -25.6
-4.1 -32.4 -37.7 -15.2 -19.4
-9.7 -27.5 -35.0 -16.6 -6.4
-23.7 -23.4
-
-17.3 -28.0
-
-15.3 -38.0
-24.1 -45.6 -30.1 -33.5 -30.3
-8.0 -23.0 -23.6 -13.6 -2.5
16.4 -7.5 27.2 -9 .9
-20.9 -31.1 -19.8 -23.3 -25.3
-17.2 -35.2 -48.0 -39.2 -26.3
-56.5 -28.5 -30.8 -54.4
-23.8 -50.1 -60.5 -43.5 -40.8
-
cases of diabetes were IDDM and 15% NIDDM. In older age groups the main type of diabetes is NIDDM, the frequency of which can be best assessed by prevalence studies [20]. Standardized survey methods and criteria for diabetes were not available before the WHO Expert Committee report in 1980 [21]. This may be one of the reasons why comparative prevalence data on NIDDM are not available in the Nordic countries. The best estimates from the existing reports suggest that the prevalence of ‘known dia betes' among population aged 30 years and above varies between 3 and 5% [11]. The
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Cause of death
Tuomilehto
Table 6. Estimated consumption of insulin and oral antidiabetic drugs (defined daily dose/1.000 inhabitants/day) in the Nordic countries in 1976 and 1986 based on the sales statistics [from 11] Country
1976 Denmark Finland Iceland Norway Sweden
Oral antidiabetics
Insulin
4.0 6.0 1.5 4.0 8.2
1986 6.4 6.7 3.2 5.6 10.8
1976
1986
4.3 11.9 2.1 5.0
6.0 13.5 3.5 5.4 10.8
11.0
proportion of diabetics over 30 years of age is about 2-3% in the Nordic countries. The recent study in Finland using the WHO sur vey criteria gave a prevalence of NIDDM of 5.7% in men and 4.6% in women aged 4564 years [Tuomilehto, unpubl. data]. In the elderly population of Finland the prevalence of diabetes was found to be high [22], The sales statistics of antidiabetic drugs show an overall increase in drug use, both insulin and oral antidiabetic drugs (table 6). These data also suggest that both IDDM and NIDDM are more common in Finland and Sweden than in the other Nordic countries. The incidence of cancer has slowly in creased in both sexes in all Nordic countries [2], Until 1973 Finland had the highest can cer incidence in men. but now Denmark is ranking first for both sexes (table 7). In wom en, Finland has clearly lower incidence than other Nordic countries. Internationally, the Nordic countries are in the middle of the list of 80 countries for which data are available. The change in cancer incidence in Finland has been less steep than in other Nordic countries. In men aged less than 60 years the incidence did not increase at all due to the
levelling off of the increasing trend in lung cancer in Finnish men around 1970. In the 1950s there was a 5.5-fold differ ence in lung cancer mortality between the highest (Finland) and lowest (Norway) inci dence, but in 1978-1980 the range was re duced to 2.8-fold. In women, lung cancer incidence has increased in all Nordic coun tries and the differences between countries have also increased. Iceland and Denmark had all the time about 2.5 times higher rates than the others. Breast cancer incidence is lowest in Finland, but the between-country difference has become smaller. Stomach can cer incidence had steadily decreased in all Nordic countries, but is still relatively high in Iceland and Finland. The 2.5-fold differ ence between the highest (Denmark) and the lowest (Finland) colon cancer rate in the early 1960s has now diminished to about 2.0. The incidence of colon cancer has in creased in both sexes in all Nordic countries, more steeply in Finland than elsewhere. Risk Factor Trends in North Karelia, Finland The reductions of all major coronary risk factors, smoking, blood pressure, and serum cholesterol were most remarkable in the province of North Karelia during 1972 to 1977 [23], Thereafter, changes were modest except for smoking in men, and the differ ences between North Karelia and the neigh boring province almost disappeared. During 1972 to 1987, the mean serum cholesterol in men decreased 0.86 mmol/1 in North Karelia [8], In 1972. in North Karelia 24.3% of men and 22.4% of women had both high choles terol and high blood pressure, but by 1982 the proportion of such high-risk subjects had fallen to about 10% [23]. These surveys sug gest that the P:S ratio of North Karelians
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46
47
Health Patterns in the Nordic Countries
Table 7. Age-adjusted incidence per 100,000 of cancer of selected sites in the Nordic countries in two time periods by sex [modified from 2] Men
Women
1956-1960
1976-1980
change. %
1955-1960
1976-1980
change, %
199 232 202 169 173
263 258 231 228 229
32 11 14 35 32
214 159 187 161 187
242 175 230 206 213
13 10 23 28 14
Lung cancer Denmark Finland Iceland' Norway Sweden2
29 60 12 12 15
56 75 27 28 26
93 25 125 133 73
5 4 6 3 4
15 7 20 6 7
200 75 233 100 75
Prostate/breast3 Denmark Finland Iceland' Norway Sweden2
19 17 17 26 27
28 33 34 40 45
47 94 100 54 67
45 27 36 38 45
62 43 58 50 58
38 59 61 32 29
30 14 16 15 18
19 6 9 17 10
-3 7 -5 7 -4 4 13 -4 4
All sites Denmark Finland Iceland Norway Sweden-
Cervix uteri Denmark Finland Iceland' Norway Sweden2 Stomach Denmark Finland Iceland' Norway Sweden2
29 56 72 36 28
15 25 29 19 16
-4 8 -5 5 -6 0 47 -4 3
18 32 31 21 14
7 13 14 10 8
-61 -5 9 -5 5 -5 2 -4 3
Colon Denmark Finland4 Iceland' Norway Sweden2
14 7 9 10 13
21 10 15 17 16
50 43 67 70 23
17 8 10 10 13
20 10 13 17 15
18 25 30 70 15
1 2 3 4
The first period in Iceland was 1955-1960. The first period in Sweden was 1958-1960. In the case of men prostate, in the case of women breast. The first period for colon cancer in Finland was 1961-1965.
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Cancer site Country
Tuomilehto
48
Table 8. Mean values of selected characteristics of male current non-smokers and smokers in Finland in 1982 and 1987 [from 25] 1982
Alcohol consumption1, g/week Saturated fat intake2, g/day Leisure time exercise3 Education, years Resting heart rate, beats/min Age, years Cigarettes smoked daily
1987
non-smokers (n = 2,779)
smokers (n = 1,729)
non-smokers (n = 1,911)
smokers (n = 1,002)
46.0 28.2 2.01 9.1 69.0 45.2 -
95.3 32.8 1.75 8.8 74.8 42.9 18.2
45.5 24.0 2.00 9.8 70.0 46.1 -
95.8 30.9 1.78 9.4 75.9 43.3 18.3
increased during the early 1970s from 0.20 to 0.28 in urban areas whereas in rural areas the P:S ratio stayed below 0.20 [12, 13]. The FINMONICA dietary survey in 1982 showed that the P:S ratio had stayed at the same level of 0.28 among urban people but there was an increase from 0.15 in 1969-1972 to 0.23 in 1982 among rural people [14]. In North Kar elian men fat provided 38.0% and in women 36.0% of total energy. The available dietary data support the findings for trends in serum cholesterol val ues in the 1970s. The major decrease in the intake of saturated fatty acids took place during 1972 to 1977 parallel with a decline in the serum cholesterol values [12. 13]. The trends in the 1980s seem to be different from those in the 1970s. Serum cholesterol values decreased significantly only in women but not in men during 1982 to 1987. The mean body mass index increased during 1972 to 1982 in eastern Finland in men from 26.0 to 26.5 kg/m2 whereas in
women it decreased from 26.9 to 26.4 kg/m2 [24] , During the 1980s smoking did not de crease further despite major national efforts to control it [23], Interestingly, we found out that smokers in our 1987 survey were not anymore much leaner than non-smokers [25] . Smokers seem to have increasingly a cluster of unhealthy habits (table 8). Blood pressure levels in North Karelia de creased considerably during 1972 to 1977, but no further improvement in the blood pressure control has taken place since the late 1970s [ 17], This observation is in accord with the trends in dietary determinants of blood pressure in Finland: body mass index has increased in men and recently also in women, alcohol consumption has increased, P:S ratio has remained low and salt intake has de creased only modestly. About 12% of the Fin nish population aged 25-64 years are cur rently under antihypertensive drug therapy. The recent comparison of risk factor data between the populations in the WFIO
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1 Self reported alcohol consumption during week preceding surveys. 2 Saturated fat from milk and fat used on bread only (see text for results of analysis of variance). 3 Four-point scale from sedentary to training for competitive endurance sports.
49
Health Patterns in the Nordic Countries
Table 9. Mean values of systolic (syst) and diastolic (diast) blood pressure (mean of two measurements), serum total cholesterol and body mass index (BM1) in the populations from the Nordic countries included in the WHO MONICA project [from 26] Men. mm Hg
Women, mm Hg
Serum cholesterol mmol/1
BM1, kg/m2
syst
diast
syst
diast
men
women
men
women
Finland North Karelia Kuopio Turku/Loimaa
144 147 142
88 90 87
142 146 137
85 86 82
6.4 6.4 6.2
6.3 6.3 6.1
26.9 26.8 26.8
27.1 26.6 25.8
Sweden Northern Sweden Gothenburg
131 n.a.
83 n.a.
128 n.a.
80 n.a.
6.3 6.2
6.2 6.1
26.0 25.3
25.5 24.3
Denmark Glostrup
127
81
124
77
6.3
6.3
23.8
24.4
Iceland
126
83
120
78
6.2
6.3
25.9
25.9
MONICA project [26] have clearly demon strated that the blood pressure levels among Finnish men and women aged 35-64 years are higher than in the other Nordic countries (table 9). Serum cholesterol levels varied only little between the Nordic MONICA centres, but body mass index was clearly higher in Finland than in other centres.
Comments Despite the very low infant mortality and the good availability of health services which are very similar in all five Nordic countries, the disease patterns amongst the middleaged populations vary markedly between these countries. In many ways Finland seems to be the Nordic country with the most unfa vorable health profile for the middle-aged,
especially among men. The trends in the incidence and mortality from CVD and ma jor cancers in the Nordic countries have been more favorable in women than men. Among women the between-country differ ences have rapidly diminished during the past years. This is mainly due to the steep decrease in coronary heart disease and stroke and lesser increase in cancer inci dence in Finland. Many of the non-communicable diseases which are main causes of morbidity and mortality in the Nordic populations are asso ciated with diet. Many of the geographic dif ferences in non-communicable diseases within the Nordic countries are probably largely determined by dietary factors, but data are not sufficient to estimate precisely the relative contribution of different nu trients to the differences in the occurrence of
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n.a. = not available.
diseases. The diet-related risk factors of noncommunicable diseases such as hypercholesterolaemia, hypertension, obesity and glu cose intolerance are more prevalent in Fin land than elsewhere in the Nordic coun tries. There is good evidence that the favorable disease trends in the Nordic countries that have been observed during the past 10-20 years have been associated with the im provement of the diet. However, the role of effective and early case finding of individu als at high risk for various non-communica ble diseases, especially cervical cancer, high blood pressure and hyperglycaemia should not be underestimated. The implementation of both dietary recommendations and pre ventive primary health care services have varied between the Nordic countries. A good example is cancer of the cervix uteri. In Fin land, Iceland and Sweden nationwide mass screening for cervical smear has been orga nized since the mid-1960s with a steep de cline in the incidence after that. In Denmark where only about 40% of women have been screened the decline has been much smaller, and in Norway where only 5% of women are screened the incidence has remained un changed [2], It can be argued that some of these differ ences might be explained by differences in other factors like genetic predisposition which could make the Finns, for instance, more sensitive to the effects of high satu rated fat intake. Actually, it has been shown that a decrease in saturated fats and an increase in the P:S ratio in the diet will effec tively lower serum cholesterol and blood pressure levels in the Finns [27, 28]. On the other hand, the higher prevalence of obesity among the Finns clearly demonstrates that their overall energy intake in relation to the
Tuomilehto
consumption is higher, and because a large proportion of energy is derived from satu rated fats, it is not unexpected that the risk factor levels in Finland are less satisfactory than in the other Nordic countries. One peculiarity in the occurrence of var ious forms of CVD and cancer in the Nordic countries is the large differential in the rates between men and women. Mortality from IHD is more than 6 times higher in men than women in eastern Finland, and elsewhere in the Nordic countries this differential is about 5-fold [5]. This fact also points to wards environmental rather than genetic origin of CVD and cancer. However, geo graphic differences for both types of dia betes, 1DDM and NIDDM, are relatively small. For instance in Finland, the occur rence of most non-communicable diseases shows a large difference between eastern and western Finland, but not for IDDM and NIDDM which are among a few diseases without such a geographic gradient. Both IDDM and NIDDM have a strong genetic susceptibility [29] and, therefore, it can be argued that genetic differences within Fin land are maybe not so large that they would be the major determinants for large geograph ic differences either for CVD or cancer. Some of the disease patterns and changes may be associated with the typical life-style in the Nordic countries. One example is the very high coffee consumption [30. 31], which is highest in the Nordic countries worldwide and which may be partly respon sible for the high levels of serum cholesterol in these countries where it has been custom ary to drink boiled coffee which can raise serum cholesterol [32], It has also been sug gested that coffee may increase the risk of IHD [33] over and above the effect mediated through cholesterol. Recently, it has also
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been speculated that high coffee consump tion in the Nordic countries might be associ ated with the extremely high incidence of IDDM in these countries [34], Although the overall population of the Nordic countries is not very large, there are distinct differences both in the genetic back ground and life-style among the populations in these countries. The geographic area cov ered by these countries is relatively large and environmental conditions vary markedly. Traditionally, it has been relatively easy to carry out population-based studies in these countries because all of them have national population registers and well-organized health care systems. Data that have accumu lated about the determinants of non-commu nicable diseases have been used for planning community-based intervention activities, like the North Karelia Project [7, 13, 15, 23], However, there is much variability not only in life-styles but also in implementing health promotion and disease prevention pro grammes among the Nordic countries [35]. The overall health situation in these coun tries is still far from ideal.
References 1 Yearbook of Nordic Statistics 1983. Stockholm. Nordic Council and Nordic Statistical Secretariat. 1984, vol. 22. 2 Hakulinen T. Andersen A, Mahler B. Pukkala E, Schon G. Tulinius H: Trends in cancer incidence in the Nordic Countries. A collaborative study of the five Nordic Cancer Registries. Acta Pathol Microbiol Immunol Scand I986:94(suppl):288. 3 World Health Organization Regional Office for Europe: Myocardial Infarction Community Regis ters. Public Health in Europe, No 5. Copenhagen. 1976. 4 Aho K, Harmsen P. Hatano S, Marquardsen J, Smirnov VE, Strasser T: Cerebrovascular disease
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in the community: Results of a WHO Collabora tive Study. Bull World Health Organ 1980;58: 113-130. 5 Tuomilehto J. Kuulasmaa K, Torppa J: The prin cipal investigators of the MONICA project: WHO MONICA project: Geographic variation in mor tality from cardiovascular diseases - Baseline data on selected population characteristics and cardio vascular mortality. World Health Stat Q 1987; 402: D 1-184. 6 Tuomilehto J. Kuulasmaa K: WHO MONICA Pro ject: Assessing CHD Mortality and Morbidity. Int J Epidemiol 1989; 18(suppl 1):S38—S45. 7 Puska P. Salonen JT. Nissinen A, et al: Change in risk factors for coronary heart disease during 10 years of a community intervention programme (North Karelia Project). Br Med J 1983:287: 1840-1844. 8 Salomaa V, Korhonen HJ, Tuomilehto J, Vartiainen E. Pietinen P. Kartovaara L, Gref C-G, Nissinen A, Puska P: Serum cholesterol distribu tion. measurement frequency and cholesterol awareness in Finland. Eur Heart J 1990:11:294301. 9 Diabetes Epidemiology Research International Group: Geographic patterns of childhood insulindependent diabetes mellitus. Diabetes 1988;37: 1113-1119. 10 Rewers M, LaPorte RE, King H. Tuomilehto J: Trends in the prevalence and incidence of dia betes: Insulin-dependent diabetes mellitus in childhood. World Health Stat Q 1988;4I. 11 Groop P-H. Klaukka T, Reunanen A: Diabeteslakemedel i Norden. Analys av orsaker till variationer i forbruknigen. Publikationer av folkpensionsanstalten ML. Helsingfors 1990. 12 Pietinen P. Nissinen A. Vartiainen E. Tuomilehto J, Uusitalo U, Ketola A, Moisio S, Puska P: Dietary changes in the North Karelia Project (1972-1982). Prev Med 1988:17:183-193. 13 Pietinen P. Vartiainen E, Korhonen HJ. Kartov aara L. Uusitalo U. Tuomilehto J. Puska P: Nutri tion as a component in the community control of cardiovascular disease (the North Karelia Pro ject). Am J Clin Nutr !989;49(suppl 5): 10171024. 14 Pietinen P. Uusitalo U, Vartiainen E, Tuomilehto J: Dietary survey of the FINMONICA project in 1982. Acta Med Scand I988;(suppl 728): 169177.
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variation in the major risk factors of coronary heart disease in men and women aged 35-64 years. World Health Stat Q 1988:41:115-138. Pietinen P, Huttunen JK: Dietary fat and blood pressure. A review. Eur Heart J 1987;8:9-17. Nissinen A. Pietinen P. Tuomilehto J. Vartiainen E, Puska P: Predictors of blood pressure change in a series of controlled dietary intervention studies. J Human Hypertens 1987:1:167-173. Barnett AH. Eff C, Leslie RDG, Pyke DA: Dia betes in identical twins, a study of 200 pairs. Diabetologia 1981:20:87-93. Tuomilehto J, Tanskanen A, Pietinen P, Aro A, Salonen J, Happonen P. Nissinen A, Puska P: Cof fee consumption is correlated with serum choles terol in middle-aged Finnish men and women. J Epidemiol Community Health 1987:41:237-242. Thelle DS. Heyden S. Fodor JG: Coffee and cho lesterol in epidemiological and experimental stud ies. Atherosclerosis 1987;67:97-103. Aro A, Tuomilehto J, Kostiainen E, Uusitalo U, Pietinen P: Boiled coffee increases serum lowdensity lipoprotein concentration. Metabolism 1987;36:1027-1030. Tverdal A. Stensvold 1. Solvoli K. Foss OP, LundLarsen P. Bjartveit K: Coffee consumption and death from coronary heart disease in middle-aged Norwegian men and women. Br Med J 1990:300: 566-569. Tuomilehto J, Tuomilehto-Wolf E. Virtala E. LaPorte R: Coffee consumption as trigger for insulin dependent diabetes mellitus in childhood. Br Med J 1990:300:642-643. Haglund B. Tillgren P: Implementation strategies in community intervention. A report from a con ference in April 1986 on the role of community analysis and focus groups in community interven tion studies. Scand J Prim Health Care 1988 (suppl 1):7—129.
Prof. Jaakko Tuomilehto Department of Epidemiology National Public Health Institute Elimaenkatu 25 A 6th floor SF-00510 Helsinki (Finland)
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15 Tuomilehto J. Pietinen P, Uusitalo U, Korhonen H, Nissinen A: Changes in sodium and potassium intake in Finland during the 1980s; in Yamori Y, StrasserT (eds): New Horizons in Preventing Car diovascular Diseases. Amsterdam. Elsevier, 1989, pp 229-239. 16 Reunanen A, Akerblom HK. Tuomilehto J: High incidence of insulin-dependent diabetes mellitus (IDDM) in children in Finland. Arct Med Res 1988;47(suppl l):535-539. 17 Tuomilehto J, Piha T, Nissinen A, Geboers J, Puska P: Trends in stroke mortality and in antihypertensive treatment in Finland from 1972 to 1984 with special reference to North Karelia. J Human Hypertens 1987;1:201-208. 18 Laakso M. Pyorala K: Age of onset and type of diabetes. Diabetes Care 1985:82:114-117. 19 Ostman J. Arnqvist H. Blohme G. et al: Epidemi ology of diabetes mellitus in Sweden. Results of the first year of a prospective study in the popula tion age group 15-34 years. Acta Med Scand 1986;220:437-445. 20 King H. Zimmet P: Trends in the prevalence and incidence of diabetes: Non-insulin dependent dia betes mellitus. World Health Stat Q 1988:41:190— 196. 21 WHO Expert Committee on Diabetes Mellitus: Second report. WHO Tech Rep Ser. 1980, No 646. 22 Tuomilehto J, Nissinen A, Kivela SL. et al: Prev alence of diabetes mellitus in elderly men aged 65 to 84 years in eastern and western Finland. Diabetologia 1986:29:611-615. 23 Tuomilehto J. Puska P, Korhonen H, Mustaniemi H, Vartiainen E, Nissinen A. Kuulasmaa K, Niemensivu H, Salonen J: Trends and determinants of ischaemic heart disease mortality in Finland: With special reference to a possible levelling off in the early 1980s. Ini J Epidemiol 1989; 18(suppl 1): s 109-s 117. 24 Jalkanen L. Tuomilehto J, Nissinen A. Puska P: Changes in body mass index in a Finnish popula tion between 1972 and 1982. J Int Med 1989:226: 163-170. 25 Marti B, Tuomilehto J. Korhonen HJ. Kartovaara L, Vartiainen E, Pietinen P, Puska P: Smoking and leanness: Evidence for change in Finland. Br Med J 1989:298:1287-1290. 26 Pajak A, Tuomilehto J, Kuulasmaa K. Ruokokoski E / The WHO Monica Project: Geographical
