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Hyperinsulinaemia and impaired glucose tolerance in young Australian aborigines SIR,-Non-insulin-dependent diabetes mellitus (NIDDM) is prevalent in rapidly urbanising, previously traditional societies, including Australian Aborigines. There may be a genetic
predisposition
which combines with environmental stresses,
including westernised diets and a sedentary life styled The genetic background might derive from a "thrifty genotype", which had a survival advantage in antiquity in gatherer and hunter-gatherer societies. A hereditary characteristic that was beneficial in the past has now been rendered detrimental by "progress" and the availability of abundant food.3 The age at onset of NIDDM in urbanising societies is unclear. Because NIDDM is a chronic disorder with significant morbidity and mortality if untreated or inadequately treated, we need to be able to detect it as early as possible in vulnerable populations. We have investigated glucose tolerance and plasma insulin levels in 100 consecutive, randomly selected, apparently healthy Aborigines aged 7-18 years who live in remote communities in the Great Sandy Desert and Fitzroy Valley regions in the tropical north of Western Australia. Blood was taken from fasting subjects for measurement of glucose and insulin; samples were taken exactly 60 and 120 min after an oral glucose challenge with 1-75 g/kg body weight (to a maximum of 75 g). On strict World Health Organisation criteria’ 2 Aborigines had impaired glucose tolerance. The median of fasting values for insulin in the 26 children less than 12 years of age was 48 pmol/1 (mean 56 [SD 28 in those older than 12 (n 74) the median was 67 pmol/1 (mean 82 [48]). The median 2 h plasma insulin levels of all children less than 12 years of age was 62 pmol/1 (85 [SD 63]) and for those 12 years of age and over it was 159 pmol/1 (218 [188], figure). With the sample of Aborigines as its own control, 6 of those over 12 years of age were in the 90th percentile for both fasting (> 5-4 mmol/1) and 2 h ( > 6-1mmol/1) glucose values. 5 of those over 12 years of age were in the 90th percentile for both 1 h ( > 720 pmol/1) and 2 h ( > 429 pmol/1) insulin values and 3 individuals were in the 90th percentile for fasting (> 130 pmol/1) and 1 h (> 720 pmol/1) and 2 h (> 429 pmol/1) insulin values. 2 children under 12 were in the 90th percentile for both 1 h ( > 6-5 mmol/1) and 2 h ( > 6-6 mmol/1) glucose and were in the 90th percentile for 1 h ( > 322 pmol/1) and 2 h (> 191 pmol/1) insulin values. The mean fasting and 2 h insulin values for our sample were significantly lower than published values for adult male desert Aborigines, but individuals more than 12 years of age with 2 h insulin values above the 90th percentile had mean insulin values equivalent to the mean for adult male desert =
Aborigines.s The observations that certain people are consistently found to be in the 90th percentile for both glucose and insulin values may reflect a predisposition to NIDDM. Plasma insulin levels and their distribution in these young Aborigines were similar to those reported by King et al6 for a periurban population aged 10-19 years from Papua New Guinea. These findings from rapidly urbanising, previously traditional
populations who
now have very high rates of impaired glucose tolerance and NIDDM indicate that the onset of this disease may be much earlier than previously recognised. Earlier detection and earlier therapeutic and preventive interventions are urgently needed.
Department of Pediatrics, University of California, San Francisco, California 94110, USA
KEITH WHITE
Department of Paediatrics, University of Western Australia, Perth, Western Australia
MICHAEL GRACEY
Department of Pediatrics, University of California
LAURIE SCHUMACHER
Health Department of Western Australia
RANDALL SPARGO
Department of Nutritional Sciences, University of California, Berkeley
NORMAN KRETCHMER
1.
Zimmet P, Dowse G, Laporte R, Finch C, Moy C. Epidemiology—its contribution to understanding of the etiology, pathogenesis and prevention of diabetes mellitus. In: Creutzfeld W, Lefebvre P, eds. Diabetes mellitus: pathophysiology and treatment.
Berlin: Springer, 1989: 5-26. 2. O’Dea K. Marked improvement in carbohydrate and lipid metabolism in diabetic Australian Aborigines after temporary rversion to traditional lifestyle. Diabetes 1984; 33: 596-603. 3. Neel JV. Diabetes mellitus: a "thrifty" genotype rendered detrimental by "progress".
Am J Hum Genet 1962; 14: 353-63. Organization. Diabetes mellitus: report of a study group. WHO Tech Rep Ser 1985; no 727. O’Dea K, Trainides K, Hopper JL, Larkins RG. Impaired glucose tolerance, hyperinsulinaemia, and hypertriglyceridemia in Australian Aborigines from the
4. World Health
5.
6.
desert. Diabetes Care 1988; 11: 23-29. King H, Alpers M, Finch C, et al. Future glucose intolerance possibly manifest youth. Lancet 1989; ii: 1098-99.
in
Reflectance meter type and management of
gestational diabetes are commonly used by diabetic patients glucose monitoring, and in this way many patients with gestational diabetes can be managed without being admitted to hospital. In gestational diabetes tight control is required, and insulin treatment is often decided upon on the basis of self-monitoring that reveals even minor hyperglycaemia. Thus small errors in blood glucose results can be significant to management. We noticed that pregnant diabetic patients using the ’Glucometer II’ (Ames) often recorded blood glucose results higher than those found simultaneously in the laboratory; results from patients using ’Reflolux II’ (Boehringer-Mannheim) accorded better with laboratory values. We have done a systematic study to evaluate the
SIR,-Reflectance meters
for blood
accuracy of these two meters in diabetic pregnancy.
26 women with gestational diabetes (gestation 22-39 weeks, diagnosis by Mahan and O’Sullivan criteria) and 35 non-pregnant diabetic patients were studied. Finger capillary blood was collected into heparinised Sarstedt tubes and immediately analysed by two glucometer Imeters and Ames test strips (program number 5 or 6) and by two reflolux II meters and BM 20/800 test strips (batches 873 and 783). Glucose in the same samples was also measured by a ’YSI Glucose Analyzer’ (Yellow Springs Instruments). At the same
Plasma insulin 2 h after
glucose load.
time venous blood was collected for measurement of haematocrit. The reflectance meters were calibrated immediately before use, according to the instructions of the manufacturers. Results were compared by Student’s t-test. For non-pregnant patients, the Ames test strips produced mean blood glucose values 4-6% lower (program 5) and 4-6% higher (program 6) than the capillary glucose concentrations found in the laboratory. The BM strips produced mean blood glucose results which differed by only 1-1% from laboratory values.
Hyperinsulinaemia and impaired glucose tolerance in young Australian aborigines SIR,-Non-insulin-dependent diabetes mellitus (NIDDM) is prevalent in rapidly urbanising, previously traditional societies, including Australian Aborigines. There may be a genetic
predisposition
which combines with environmental stresses,
including westernised diets and a sedentary life styled The genetic background might derive from a "thrifty genotype", which had a survival advantage in antiquity in gatherer and hunter-gatherer societies. A hereditary characteristic that was beneficial in the past has now been rendered detrimental by "progress" and the availability of abundant food.3 The age at onset of NIDDM in urbanising societies is unclear. Because NIDDM is a chronic disorder with significant morbidity and mortality if untreated or inadequately treated, we need to be able to detect it as early as possible in vulnerable populations. We have investigated glucose tolerance and plasma insulin levels in 100 consecutive, randomly selected, apparently healthy Aborigines aged 7-18 years who live in remote communities in the Great Sandy Desert and Fitzroy Valley regions in the tropical north of Western Australia. Blood was taken from fasting subjects for measurement of glucose and insulin; samples were taken exactly 60 and 120 min after an oral glucose challenge with 1-75 g/kg body weight (to a maximum of 75 g). On strict World Health Organisation criteria’ 2 Aborigines had impaired glucose tolerance. The median of fasting values for insulin in the 26 children less than 12 years of age was 48 pmol/1 (mean 56 [SD 28 in those older than 12 (n 74) the median was 67 pmol/1 (mean 82 [48]). The median 2 h plasma insulin levels of all children less than 12 years of age was 62 pmol/1 (85 [SD 63]) and for those 12 years of age and over it was 159 pmol/1 (218 [188], figure). With the sample of Aborigines as its own control, 6 of those over 12 years of age were in the 90th percentile for both fasting (> 5-4 mmol/1) and 2 h ( > 6-1mmol/1) glucose values. 5 of those over 12 years of age were in the 90th percentile for both 1 h ( > 720 pmol/1) and 2 h ( > 429 pmol/1) insulin values and 3 individuals were in the 90th percentile for fasting (> 130 pmol/1) and 1 h (> 720 pmol/1) and 2 h (> 429 pmol/1) insulin values. 2 children under 12 were in the 90th percentile for both 1 h ( > 6-5 mmol/1) and 2 h ( > 6-6 mmol/1) glucose and were in the 90th percentile for 1 h ( > 322 pmol/1) and 2 h (> 191 pmol/1) insulin values. The mean fasting and 2 h insulin values for our sample were significantly lower than published values for adult male desert Aborigines, but individuals more than 12 years of age with 2 h insulin values above the 90th percentile had mean insulin values equivalent to the mean for adult male desert =
Aborigines.s The observations that certain people are consistently found to be in the 90th percentile for both glucose and insulin values may reflect a predisposition to NIDDM. Plasma insulin levels and their distribution in these young Aborigines were similar to those reported by King et al6 for a periurban population aged 10-19 years from Papua New Guinea. These findings from rapidly urbanising, previously traditional
populations who
now have very high rates of impaired glucose tolerance and NIDDM indicate that the onset of this disease may be much earlier than previously recognised. Earlier detection and earlier therapeutic and preventive interventions are urgently needed.
Department of Pediatrics, University of California, San Francisco, California 94110, USA
KEITH WHITE
Department of Paediatrics, University of Western Australia, Perth, Western Australia
MICHAEL GRACEY
Department of Pediatrics, University of California
LAURIE SCHUMACHER
Health Department of Western Australia
RANDALL SPARGO
Department of Nutritional Sciences, University of California, Berkeley
NORMAN KRETCHMER
1.
Zimmet P, Dowse G, Laporte R, Finch C, Moy C. Epidemiology—its contribution to understanding of the etiology, pathogenesis and prevention of diabetes mellitus. In: Creutzfeld W, Lefebvre P, eds. Diabetes mellitus: pathophysiology and treatment.
Berlin: Springer, 1989: 5-26. 2. O’Dea K. Marked improvement in carbohydrate and lipid metabolism in diabetic Australian Aborigines after temporary rversion to traditional lifestyle. Diabetes 1984; 33: 596-603. 3. Neel JV. Diabetes mellitus: a "thrifty" genotype rendered detrimental by "progress".
Am J Hum Genet 1962; 14: 353-63. Organization. Diabetes mellitus: report of a study group. WHO Tech Rep Ser 1985; no 727. O’Dea K, Trainides K, Hopper JL, Larkins RG. Impaired glucose tolerance, hyperinsulinaemia, and hypertriglyceridemia in Australian Aborigines from the
4. World Health
5.
6.
desert. Diabetes Care 1988; 11: 23-29. King H, Alpers M, Finch C, et al. Future glucose intolerance possibly manifest youth. Lancet 1989; ii: 1098-99.
in
Reflectance meter type and management of
gestational diabetes are commonly used by diabetic patients glucose monitoring, and in this way many patients with gestational diabetes can be managed without being admitted to hospital. In gestational diabetes tight control is required, and insulin treatment is often decided upon on the basis of self-monitoring that reveals even minor hyperglycaemia. Thus small errors in blood glucose results can be significant to management. We noticed that pregnant diabetic patients using the ’Glucometer II’ (Ames) often recorded blood glucose results higher than those found simultaneously in the laboratory; results from patients using ’Reflolux II’ (Boehringer-Mannheim) accorded better with laboratory values. We have done a systematic study to evaluate the
SIR,-Reflectance meters
for blood
accuracy of these two meters in diabetic pregnancy.
26 women with gestational diabetes (gestation 22-39 weeks, diagnosis by Mahan and O’Sullivan criteria) and 35 non-pregnant diabetic patients were studied. Finger capillary blood was collected into heparinised Sarstedt tubes and immediately analysed by two glucometer Imeters and Ames test strips (program number 5 or 6) and by two reflolux II meters and BM 20/800 test strips (batches 873 and 783). Glucose in the same samples was also measured by a ’YSI Glucose Analyzer’ (Yellow Springs Instruments). At the same
Plasma insulin 2 h after
glucose load.
time venous blood was collected for measurement of haematocrit. The reflectance meters were calibrated immediately before use, according to the instructions of the manufacturers. Results were compared by Student’s t-test. For non-pregnant patients, the Ames test strips produced mean blood glucose values 4-6% lower (program 5) and 4-6% higher (program 6) than the capillary glucose concentrations found in the laboratory. The BM strips produced mean blood glucose results which differed by only 1-1% from laboratory values.
