Abnormal Glucose Tolerance and Other Coronary Heart Disease Risk Factors in an Isolated Aboriginal Community in Central Australia

Abstract

OBJECTIVE To determine the age- and sex-specific prevalence of diabetes, impaired glucose tolerance (IGT), and coronary heart disease risk factors in a remote central Australian Aboriginal community maintaining some degree of traditional lifestyle, living in homeland communities on their ancestral land. RESEARCH DESIGN AND METHODS A cross-sectional survey of 437 subjects ≥ 15 years of age (189 men, 248 women), representing 80% of the adult population residing in the community at the time of the survey, was performed and the following parameters measured: BMI, glucose tolerance, circulating insulin and lipids, and blood pressure. RESULTS The mean BMI for this population was 22.9 ± 4.8 kg/m2. The prevalence of diabetes in the age group of 15–34 years (103 men and 140 women) was 2 and 6% for men and women, respectively. In the 35-years-and-older age group (86 men and 108 women), diabetes prevalence was 19 and 13% for men and women, respectively. Over half the diabetic subjects did not exhibit fasting hyperglycemia. IGT occurred in 8 and 15% of younger men and women, respectively, and in 17 and 32% of older men and women, respectively. Smoking was common among men (53% current smokers) but rare among women (2% current smokers). The prevalence of hypercholesterolemia, hypertriglyceridemia, hypertension, and overweight rose with increasing degrees of glucose intolerance. The two communities adjacent to the only store in the area had a higher prevalence of abnormal glucose tolerance than did the more remote homeland communities (odds ratio for abnormal glucose tolerance: 2.92; 95% CI 1.51−5.63). CONCLUSIONS Despite their relative leanness, this Aboriginal population exhibited relatively high prevalences of IGT and diabetes without fasting hyperglycemia. The data suggest a protective effect of a decentralized mode of living, as opposed to a more urbanized lifestyle, on the occurrence of glucose intolerance. Abnormal lipid profiles (particularly high triglycerides and low HDL cholesterol) and the high prevalence of smoking in men indicated a high-risk profile for coronary heart disease in this population.