This article was downloaded by: [Memorial University of Newfoundland] On: 26 January 2015, At: 23:39 Publisher: Routledge Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Journal of Nutrition For the Elderly Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/wjne20
Dietary Calcium Intake and Other Risk Factors a
Iris Chi DSW & K K Pun MD
b
a
Lecturer, Department of Social Work, The University of Hong Kong, Monterey Park, CA, 91754 b
Lecturer, Department of Medicine, University of Hong Kong Published online: 18 Oct 2008.
To cite this article: Iris Chi DSW & K K Pun MD (1991) Dietary Calcium Intake and Other Risk Factors, Journal of Nutrition For the Elderly, 10:4, 73-89, DOI: 10.1300/J052v10n04_05 To link to this article: http://dx.doi.org/10.1300/J052v10n04_05
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-andconditions
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Dietary Calcium Intake and Other Risk Factors: study of the Fractured Patients in Hong Kong Iris Chi, DSW K. K. Pun, MD
ABSTRACT. Osteoporosis has become a major health problem among theqlderly in Hong Kong. This study compares the level of dietaly calcium intake and the differences in various risk factors among elderly fracture patients and elderly without fractures. Furthermore, this study identifies the relationship between the risk factors and the amount of calcium intake; and classifies the fracture patients and the low calcium intake group. Although the design of the present study precludes testing causal hypotheses, the findings are suggestive of factors that are likely to be important in a program to reduce fractures among elderly populations.
INTRODUCTION Osteoporosis is an age-related disorder characterized by decreased bone mass and increased susceptibility to fractures (MorIris Chi is Lecturer at the Deaartment of Social Work, Universitv of Hong Kong. K. K. Pun is Lecturer at thk Department of ~edicine,university of ~ o n g Kong. The data used in this analysis come from astudy: Social Aspects of Osteoporosis among the Elderly in Hong Kong, which is supported by CCRG Research Grant, University of Hong Kong. The research is administered by the Department of Social Work and Social Administration, University of Hong Kong. Address correspondence to Dr. Iris Chi, 296 Mesa Way, Monterey Park, CA 91754. Journal of Nutrition for the Elderly, Vol. 10(4) 1991 73 O 1991 by The Haworth Press, Inc. All rights reserved.
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
74
JOURNAL OF NUTRITION FOR THE ELDERLY
gan, 1973). The impact of such age-related fractures on the elderly and overall public health will become more significant considering recent increases in life expectancy. Fractures in elderly, particularly hip fractures, are associated with considerable medical care, prolonged impairment, and an elevated mortality. Thus, osteoporosis has been identified in western societies to be a great public health problem deserving intense investigation (Gennari, 1987). Osteoporosis is also becoming a major health problem among the elderly in Hong Kong. It is estimated that a total of 25,000 fractures every year occur as a result of it (Pun, 1988). In one of the major local hospitals, Queen Mary Hospital, and its affiliated emergency department which care for about 1.0 million people living on Hong Kong Island, there are, on the average, 6 new admissions with femoral neck fracture every day. Although there are no statistics available on the age distribution of the patients, it is believed the majority of them are elderly. As many as 5 to 20 percent of those patients die of cardiopulmonary complications, thus making hip fracture due to osteoporosis one of the major indirect causes of death in Hong Kong. Furthermore, up to 50 percent of hip fracture survivors require prolonged nursing home care. In addition to femoral neck fracture, spine and Colles' fractures also cause significant morbidity in the elderly population. These two additional types of fracture are also associated with osteoporosis. Spine and Colles' fractures outnumber the incidence of femoral neck fracture by several fold. Fair skin, small bones, smoking, consuming alcoholic beverages, stressful daily routines, milk allergy, ovary removal and lack of exercise, have been identified as risk factors for the disease in Western societies. Inadequate calcium intake has been documented as one of the major causes of osteoporosis (Avioli, 1987a). Many studies have found that the dietary calcium intake of osteoporotic patients is lower than controls (Riggs et al., 1976; Nordin et al., 1979). In a Hong Kong study, patients with fractures had significantly lower calcium intake than matched controls (Pun, 1989a). Calcium supplements can be utilized to maximize bone health and to decrease the rate of bone loss (Avioli, 1987b). This study compares the levels of dietary calcium intake and the differences in various risk factors among elderly fracture patients
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Iris Chi and K K. Pun
75
and elderly without fractures. The objectives of this study are: (1) to explore the differences between these two groups in the amount of daily calcium intake; (2) to compare the risk factors of osteoporosis between these two groups; (3) to identify the relationship between these risk factors and the amount of calcium intake; and (4) to classify the fracture patients and the low calcium intake group. RESEARCH DESIGN A sample of 105 elderly people in Hong Kong were examined. The experimental group was made up of 41 patients who were admitted to the Queen Mary Hospital with diagnosis of fracture problems (such as Colle's fracture; Distal Radium Fracture; Distal Radium and u/n fracture; Lumber collapse; hip fracture; and others). The matched group was 64 members of an elderly social center. Queen Mary Hospital is one of the largest local hospitals, fracture patients represent roughly one third of the total population. However, this study cannot be claimed to be representative of the total elderly population of Hong Kong because no rigorous random sampling method was applied. Subjects from both groups were interviewed using a questionnaire administered bv a trained research assistant. The auestionnaire contained five major areas: (1) demographics; (2) medical history; (3) daily dietary calcium intake assessment; (4) health habits and (5) selected risk factors for osteoporosis. The patients were interviewed either in the hospital or outpatient clinics. The matched group was interviewed in the elderly social center. Daily dietary calcium intake was determined by a food frequency assessment scale (Appendix 1). Twenty-four different types of food rich in calcium and commonly consumed by Southern Chinese in Hong Kong were included in the scale. The calcium content of these common food items in the Chinese diet has been studied previously (Pun, 1989b) and the scale values used in this project were adapted from that study. These foods included milk, bean curd, vegetables, fish, and other foods. The food frequency ranged from daily, weekly, monthly to never.
76
JOURNAL OF NUTRITION FOR THE ELDERLY
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
FINDINGS
Table 1 shows no significant differences between the patients and the matched group in the distribution of sex, level of education, marital status, and living arrangement. However, significant differences were found in the distribution of age, working status, and total daily dietary calcium intake, The matched group was older and less likely to work compared with subjects with fractures. The matched group's age ranged from 53 to 83 (mean age is 67.7) while the patient group's age ranged from 50 to 88 (mean age is 65.7). In the present study, we used an intake of 500 mg or below of dietary calcium per day as a cutoff point for low intake. Although international standards for calcium intake are higher than ours, the decision on a cutoff level of 500 mg was based on local clinical observations and previous research findings. In previous studies (Lau, 1987; Pun, 1989a), it was found that the average intake of calcium in young adults was approximately 500 mg per day, 300 mg in those aged above 60, and even lower in fracture patients. In the present study, close to 83 percent of the patients had daily calcium intake of 500 mg or below. Over half (58%) of the matched controls had low calcium intakes as well. Table 2 examines risk factors such as current smoking, past smoking, regularly drinking alcoholic beverages andlor soft drinks, and regularly exercising. Other risk factors included having stressful daily routines, fair-skin, small-bones, allergies to milk, and having ovaries removed. Amongst these factors, only past smoking and exercise were found to be significantly different between the two groups. The matched group had more past smokers. Regular exercise was defined as having exercise at least once a week. More of the matched group regularly exercised compared to their patient counterparts. It is noteworthy that over a quarter of the patients did not exercise at all. Table 3 compares different levels of total daily dietary calcium intake with the same list of risk factors examined in Table 2. These data show that consumption of alcoholic beverage and soft drink are associated with different levels of calcium intake. The questionnaire item for alcohol drinking was: "How often do you drink wine, beer, or liquor?" Drinking alcohol more than twice a week was
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
I& Chi and K. K. Pun
77
considered an undesirable response. The questionnaire item for soft drinks was: "How often do you consume soft drink?" Drinking soft drinks more often than three times a week was considered a negative response. Persons with low calcium intake were three times more likely to be alcohol drinkers than those who ingested more than 500 mg of calcium per day. However, high calcium intake was associated with more frequent consumption of soft drinks. Table 4 reports data from a discriminate analysis classifying fracture patients and also low calcium intake. The model for classifying fracture patients included four criteria: past smoking, exercise, working, and age. These were identified as significant variables in the bivariate analysis (Table 2). Seventy one percent of the patients in this group met all four criteria. The model classifying low calcium intake also included the four items found to be significant in Table 3 (alcohol, soft drinks, working, and age). Over 68 percent of the persons with low calcium intake met all four of these criteria. Both models were significant and indicated good discriminary power. CONCLUSION
The design of the present study precludes testing causal hypotheses. However, the data are suggestive of factors that are likely to be important in a program to reduce fractures among elderly populations. For example, fracture patients in our study had much lower daily dietary calcium intake than non-patients, even though the nonpatients were older. The risk factors that distinguished fracture patients from non-patients were two life style habits, namely smoking in the past and inadequate exercise. As shown in previous studies, regular exercise was associated with lower incidence of fractures. Somewhat surprising was the finding that the non-patients were more likely to have a history of smoking. Age differences may have played a part, because the matched group was older and the antismoking campaign in Hong Kong is a recent local phenomenon. Persons with low dietary calcium intake levels were more likely to drink alcoholic beverages. From these observations, it is tempting to speculate that a health education program focusing on consuming high dietary calcium and maintaining a healthy life style
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
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NNU)
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Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
TABLE 3. Comparison of Risk Factors Between Different Calcium Intakes (percentage distribution)
Current smoker:
N.S.
Fast smker:
N.S.
Drinker:
0.10
Ekmise:
no few daily
N.S.
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
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86
JOURNAL OF NUTRITION FOR THE ELDERLY
would be helpful in reducing the potential for fracture in the elderly. Elderly persons should be advised to eat food with high calcium content, regularly exercise, and restrict their alcohol consumption. Finally, it is likely that dietary calcium intake in Hong Kong is lower than the threshold for maintaining normal bone mass. Thus calcium supplementation may be a useful practice for this population.
Received: November 1989 Revised: May 1990 Revised: August 1990 Revised: December 1990 Accepted: January 1991 REFERENCES Avioli, L. V. (1987a) Calcium, the menopause and osteoporosis. In D. V. Cohn & T. I. Martin (Eds.), Osteoporosis (pp. 7-10). Elsevier Science Publishers BV (Biomedical Division), The Netherlands. Avioli. L. V. (1987b) The calcium controversy and the recommended dietary allowance. In The Osteoporotic Syndrome (pp. 57-66). Grune & Stratton, Inc. Gennari, C. (1987) Epidemiology and financial aspects of osteoporosis. In D. V. Cohn & T. J. Martin (Eds.), Osteoporosis (pp. 1-2). Elsevier Science Publishers BV (Biomedical Division), The Netherlands. Horseman, A., Gallaghar, J. C., Simpson, M., & Nordin, B. E. C. (1977) Prospective trial of oestrogen and calcium in osteoporosis. British Medical Journal, 2:789-792. Lau, E. M. C., & Donnan, S. P. B. (1987) Physical labour and fractured proximal femur in Chinese. American Journal of E~idemiolopv.126(4):753. Lau, E. M. C. (1988) The prevention of hip fraciure in ~ o & ~ o n g . ~Kong on~ Journal of Gerontology, 2(1):16-18. Morgan, Brian (1973) Osteomalacia, Renal Osteodystrophy, and Osteoporosis. Chapter 11: Effect of Ageing on the Bone, Thomas Publishing Company, pp. 248-259. Nordin, B. E. C., Horseman, A., Marshall, D. H., Simpson, M., & Waterhouse, G. M. (1979) Calcium requirement and calcium therapy. Clinical Orthopaedics and related research, 140:216-239. Pun, K. K. (1988) Osteoporosis-The Treatable and Preventable Epidemic. Hong Kong Practitioner, 10(4):3132-3135. Pun, K. K., Chan, L. W. L., Chung, V., & Wong, F. H. W. (1989a) Calcium and Other Dietary Constituents in Hong Kong Chinese in Relation to Age and Osteoporosis. Journal of Applied Nutrition. (in press).
Iris Chi and
K. K. f i n
87
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Pun, K. K., Chan, L. W. L., Chung, V., & Wong, F. H. W. (1989b) Calcium Content o f Common Food Items in Chinese Diet. Calcif. Tissure Int. (in press). Riggs, B. L., Kelly, P. J., Kinney, V. E., Sholz, D. A,, & Bianco, A. J. (1976) Calcium deficiency and osteoporosis: observations in 166 patients. The Journal of .Bone and Joint Surgery, 49A(5):15-25.
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Appendix 1 Food Frequency Assessment Scale
Frequency is checked by:
0
1 2 3
Food T v ~ e
Standard Servinq
Milk Soybean milk Broccoli Chinese broccoli Greenpea Lettace Wong Are Pak Shellfish
1 cup 1 cup gram gram gram gram gram gram
Never Once a month Once a week Once a day or more
Usual Servinq
Freuuencv
Calcium content1
Total Intake
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Fish Egg Beans Orange Bread Rice Pancake Lotus Nuts Peanuts Beancurd p l a i n Beancurd d r i e d Dried f i s h Sardine f i s h Mackerel f i s h Shark f i n Sesame p a s t e
1
gram 1 large gram 1 medium 1 piece 1 cup 1 piece 1 bowl gram 1 piece gram gram gram gram gram gram
Calcium c o n t e n t is measured by mg/100g f o r s o l i d food i t e m s , mg/100/ml f o r l i q u i d food items.
Journal of Nutrition For the Elderly Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/wjne20
Dietary Calcium Intake and Other Risk Factors a
Iris Chi DSW & K K Pun MD
b
a
Lecturer, Department of Social Work, The University of Hong Kong, Monterey Park, CA, 91754 b
Lecturer, Department of Medicine, University of Hong Kong Published online: 18 Oct 2008.
To cite this article: Iris Chi DSW & K K Pun MD (1991) Dietary Calcium Intake and Other Risk Factors, Journal of Nutrition For the Elderly, 10:4, 73-89, DOI: 10.1300/J052v10n04_05 To link to this article: http://dx.doi.org/10.1300/J052v10n04_05
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-andconditions
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Dietary Calcium Intake and Other Risk Factors: study of the Fractured Patients in Hong Kong Iris Chi, DSW K. K. Pun, MD
ABSTRACT. Osteoporosis has become a major health problem among theqlderly in Hong Kong. This study compares the level of dietaly calcium intake and the differences in various risk factors among elderly fracture patients and elderly without fractures. Furthermore, this study identifies the relationship between the risk factors and the amount of calcium intake; and classifies the fracture patients and the low calcium intake group. Although the design of the present study precludes testing causal hypotheses, the findings are suggestive of factors that are likely to be important in a program to reduce fractures among elderly populations.
INTRODUCTION Osteoporosis is an age-related disorder characterized by decreased bone mass and increased susceptibility to fractures (MorIris Chi is Lecturer at the Deaartment of Social Work, Universitv of Hong Kong. K. K. Pun is Lecturer at thk Department of ~edicine,university of ~ o n g Kong. The data used in this analysis come from astudy: Social Aspects of Osteoporosis among the Elderly in Hong Kong, which is supported by CCRG Research Grant, University of Hong Kong. The research is administered by the Department of Social Work and Social Administration, University of Hong Kong. Address correspondence to Dr. Iris Chi, 296 Mesa Way, Monterey Park, CA 91754. Journal of Nutrition for the Elderly, Vol. 10(4) 1991 73 O 1991 by The Haworth Press, Inc. All rights reserved.
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
74
JOURNAL OF NUTRITION FOR THE ELDERLY
gan, 1973). The impact of such age-related fractures on the elderly and overall public health will become more significant considering recent increases in life expectancy. Fractures in elderly, particularly hip fractures, are associated with considerable medical care, prolonged impairment, and an elevated mortality. Thus, osteoporosis has been identified in western societies to be a great public health problem deserving intense investigation (Gennari, 1987). Osteoporosis is also becoming a major health problem among the elderly in Hong Kong. It is estimated that a total of 25,000 fractures every year occur as a result of it (Pun, 1988). In one of the major local hospitals, Queen Mary Hospital, and its affiliated emergency department which care for about 1.0 million people living on Hong Kong Island, there are, on the average, 6 new admissions with femoral neck fracture every day. Although there are no statistics available on the age distribution of the patients, it is believed the majority of them are elderly. As many as 5 to 20 percent of those patients die of cardiopulmonary complications, thus making hip fracture due to osteoporosis one of the major indirect causes of death in Hong Kong. Furthermore, up to 50 percent of hip fracture survivors require prolonged nursing home care. In addition to femoral neck fracture, spine and Colles' fractures also cause significant morbidity in the elderly population. These two additional types of fracture are also associated with osteoporosis. Spine and Colles' fractures outnumber the incidence of femoral neck fracture by several fold. Fair skin, small bones, smoking, consuming alcoholic beverages, stressful daily routines, milk allergy, ovary removal and lack of exercise, have been identified as risk factors for the disease in Western societies. Inadequate calcium intake has been documented as one of the major causes of osteoporosis (Avioli, 1987a). Many studies have found that the dietary calcium intake of osteoporotic patients is lower than controls (Riggs et al., 1976; Nordin et al., 1979). In a Hong Kong study, patients with fractures had significantly lower calcium intake than matched controls (Pun, 1989a). Calcium supplements can be utilized to maximize bone health and to decrease the rate of bone loss (Avioli, 1987b). This study compares the levels of dietary calcium intake and the differences in various risk factors among elderly fracture patients
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Iris Chi and K K. Pun
75
and elderly without fractures. The objectives of this study are: (1) to explore the differences between these two groups in the amount of daily calcium intake; (2) to compare the risk factors of osteoporosis between these two groups; (3) to identify the relationship between these risk factors and the amount of calcium intake; and (4) to classify the fracture patients and the low calcium intake group. RESEARCH DESIGN A sample of 105 elderly people in Hong Kong were examined. The experimental group was made up of 41 patients who were admitted to the Queen Mary Hospital with diagnosis of fracture problems (such as Colle's fracture; Distal Radium Fracture; Distal Radium and u/n fracture; Lumber collapse; hip fracture; and others). The matched group was 64 members of an elderly social center. Queen Mary Hospital is one of the largest local hospitals, fracture patients represent roughly one third of the total population. However, this study cannot be claimed to be representative of the total elderly population of Hong Kong because no rigorous random sampling method was applied. Subjects from both groups were interviewed using a questionnaire administered bv a trained research assistant. The auestionnaire contained five major areas: (1) demographics; (2) medical history; (3) daily dietary calcium intake assessment; (4) health habits and (5) selected risk factors for osteoporosis. The patients were interviewed either in the hospital or outpatient clinics. The matched group was interviewed in the elderly social center. Daily dietary calcium intake was determined by a food frequency assessment scale (Appendix 1). Twenty-four different types of food rich in calcium and commonly consumed by Southern Chinese in Hong Kong were included in the scale. The calcium content of these common food items in the Chinese diet has been studied previously (Pun, 1989b) and the scale values used in this project were adapted from that study. These foods included milk, bean curd, vegetables, fish, and other foods. The food frequency ranged from daily, weekly, monthly to never.
76
JOURNAL OF NUTRITION FOR THE ELDERLY
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
FINDINGS
Table 1 shows no significant differences between the patients and the matched group in the distribution of sex, level of education, marital status, and living arrangement. However, significant differences were found in the distribution of age, working status, and total daily dietary calcium intake, The matched group was older and less likely to work compared with subjects with fractures. The matched group's age ranged from 53 to 83 (mean age is 67.7) while the patient group's age ranged from 50 to 88 (mean age is 65.7). In the present study, we used an intake of 500 mg or below of dietary calcium per day as a cutoff point for low intake. Although international standards for calcium intake are higher than ours, the decision on a cutoff level of 500 mg was based on local clinical observations and previous research findings. In previous studies (Lau, 1987; Pun, 1989a), it was found that the average intake of calcium in young adults was approximately 500 mg per day, 300 mg in those aged above 60, and even lower in fracture patients. In the present study, close to 83 percent of the patients had daily calcium intake of 500 mg or below. Over half (58%) of the matched controls had low calcium intakes as well. Table 2 examines risk factors such as current smoking, past smoking, regularly drinking alcoholic beverages andlor soft drinks, and regularly exercising. Other risk factors included having stressful daily routines, fair-skin, small-bones, allergies to milk, and having ovaries removed. Amongst these factors, only past smoking and exercise were found to be significantly different between the two groups. The matched group had more past smokers. Regular exercise was defined as having exercise at least once a week. More of the matched group regularly exercised compared to their patient counterparts. It is noteworthy that over a quarter of the patients did not exercise at all. Table 3 compares different levels of total daily dietary calcium intake with the same list of risk factors examined in Table 2. These data show that consumption of alcoholic beverage and soft drink are associated with different levels of calcium intake. The questionnaire item for alcohol drinking was: "How often do you drink wine, beer, or liquor?" Drinking alcohol more than twice a week was
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
I& Chi and K. K. Pun
77
considered an undesirable response. The questionnaire item for soft drinks was: "How often do you consume soft drink?" Drinking soft drinks more often than three times a week was considered a negative response. Persons with low calcium intake were three times more likely to be alcohol drinkers than those who ingested more than 500 mg of calcium per day. However, high calcium intake was associated with more frequent consumption of soft drinks. Table 4 reports data from a discriminate analysis classifying fracture patients and also low calcium intake. The model for classifying fracture patients included four criteria: past smoking, exercise, working, and age. These were identified as significant variables in the bivariate analysis (Table 2). Seventy one percent of the patients in this group met all four criteria. The model classifying low calcium intake also included the four items found to be significant in Table 3 (alcohol, soft drinks, working, and age). Over 68 percent of the persons with low calcium intake met all four of these criteria. Both models were significant and indicated good discriminary power. CONCLUSION
The design of the present study precludes testing causal hypotheses. However, the data are suggestive of factors that are likely to be important in a program to reduce fractures among elderly populations. For example, fracture patients in our study had much lower daily dietary calcium intake than non-patients, even though the nonpatients were older. The risk factors that distinguished fracture patients from non-patients were two life style habits, namely smoking in the past and inadequate exercise. As shown in previous studies, regular exercise was associated with lower incidence of fractures. Somewhat surprising was the finding that the non-patients were more likely to have a history of smoking. Age differences may have played a part, because the matched group was older and the antismoking campaign in Hong Kong is a recent local phenomenon. Persons with low dietary calcium intake levels were more likely to drink alcoholic beverages. From these observations, it is tempting to speculate that a health education program focusing on consuming high dietary calcium and maintaining a healthy life style
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
$
V
Y
I-i 7
d cO m \D
1?
'0. -?
\D
mm ro
? ?1 Or-I-i m
m
???
-4'7.4
mmm
EON
..
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
U)
d &4 Nm 4 d'd
t? 'I?
CO d OI 0
I-
N I-
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Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
NNU)
u; m 0
q 0
d
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
TABLE 3. Comparison of Risk Factors Between Different Calcium Intakes (percentage distribution)
Current smoker:
N.S.
Fast smker:
N.S.
Drinker:
0.10
Ekmise:
no few daily
N.S.
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
Downloaded by [Memorial University of Newfoundland] at 23:39 26 January 2015
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86
JOURNAL OF NUTRITION FOR THE ELDERLY
would be helpful in reducing the potential for fracture in the elderly. Elderly persons should be advised to eat food with high calcium content, regularly exercise, and restrict their alcohol consumption. Finally, it is likely that dietary calcium intake in Hong Kong is lower than the threshold for maintaining normal bone mass. Thus calcium supplementation may be a useful practice for this population.
Received: November 1989 Revised: May 1990 Revised: August 1990 Revised: December 1990 Accepted: January 1991 REFERENCES Avioli, L. V. (1987a) Calcium, the menopause and osteoporosis. In D. V. Cohn & T. I. Martin (Eds.), Osteoporosis (pp. 7-10). Elsevier Science Publishers BV (Biomedical Division), The Netherlands. Avioli. L. V. (1987b) The calcium controversy and the recommended dietary allowance. In The Osteoporotic Syndrome (pp. 57-66). Grune & Stratton, Inc. Gennari, C. (1987) Epidemiology and financial aspects of osteoporosis. In D. V. Cohn & T. J. Martin (Eds.), Osteoporosis (pp. 1-2). Elsevier Science Publishers BV (Biomedical Division), The Netherlands. Horseman, A., Gallaghar, J. C., Simpson, M., & Nordin, B. E. C. (1977) Prospective trial of oestrogen and calcium in osteoporosis. British Medical Journal, 2:789-792. Lau, E. M. C., & Donnan, S. P. B. (1987) Physical labour and fractured proximal femur in Chinese. American Journal of E~idemiolopv.126(4):753. Lau, E. M. C. (1988) The prevention of hip fraciure in ~ o & ~ o n g . ~Kong on~ Journal of Gerontology, 2(1):16-18. Morgan, Brian (1973) Osteomalacia, Renal Osteodystrophy, and Osteoporosis. Chapter 11: Effect of Ageing on the Bone, Thomas Publishing Company, pp. 248-259. Nordin, B. E. C., Horseman, A., Marshall, D. H., Simpson, M., & Waterhouse, G. M. (1979) Calcium requirement and calcium therapy. Clinical Orthopaedics and related research, 140:216-239. Pun, K. K. (1988) Osteoporosis-The Treatable and Preventable Epidemic. Hong Kong Practitioner, 10(4):3132-3135. Pun, K. K., Chan, L. W. L., Chung, V., & Wong, F. H. W. (1989a) Calcium and Other Dietary Constituents in Hong Kong Chinese in Relation to Age and Osteoporosis. Journal of Applied Nutrition. (in press).
Iris Chi and
K. K. f i n
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Pun, K. K., Chan, L. W. L., Chung, V., & Wong, F. H. W. (1989b) Calcium Content o f Common Food Items in Chinese Diet. Calcif. Tissure Int. (in press). Riggs, B. L., Kelly, P. J., Kinney, V. E., Sholz, D. A,, & Bianco, A. J. (1976) Calcium deficiency and osteoporosis: observations in 166 patients. The Journal of .Bone and Joint Surgery, 49A(5):15-25.
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Appendix 1 Food Frequency Assessment Scale
Frequency is checked by:
0
1 2 3
Food T v ~ e
Standard Servinq
Milk Soybean milk Broccoli Chinese broccoli Greenpea Lettace Wong Are Pak Shellfish
1 cup 1 cup gram gram gram gram gram gram
Never Once a month Once a week Once a day or more
Usual Servinq
Freuuencv
Calcium content1
Total Intake
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Fish Egg Beans Orange Bread Rice Pancake Lotus Nuts Peanuts Beancurd p l a i n Beancurd d r i e d Dried f i s h Sardine f i s h Mackerel f i s h Shark f i n Sesame p a s t e
1
gram 1 large gram 1 medium 1 piece 1 cup 1 piece 1 bowl gram 1 piece gram gram gram gram gram gram
Calcium c o n t e n t is measured by mg/100g f o r s o l i d food i t e m s , mg/100/ml f o r l i q u i d food items.
