OBESITY, DIABETES, AND HYPERLIPIDEMIA IN A CENTRAL AUSTRALIAN ABORIGINAL COMMUNITY WITH A LONG HISTORY OF ACCULTURATION

OBJECTIVE - To determine the age- and sex-specific prevalence of diabetes and to examine associations between related anthropometric and metabolic abnormalities in an Aboriginal community in central Australia with a long history of acculturation. RESEARCH DESIGN AND METHODS - We used a cross-sectional survey of 353 adults >15 yr of age (87% response rate) and measured the following parameters: weight, height, circumferences of waist and hips; glucose, insulin, cholesterol, triglyceride, and high-density lipoprotein cholesterol in fasting plasma; and plasma glucose and insulin 2 h after 75 g oral glucose. RESULTS - The prevalence of diabetes was 29.6% in survey participants >35 yr of age and 5.3% in those <35 yr of age. Impaired glucose tolerance also occurred with higher frequency in those >35 yr of age (14.8 vs. 4.7%). Of those >35 yr of age, 75% of the women and 5 1% of the men were overweight or obese, with a body mass index greater-than-or-equal-to 25 kg/m2. A large insulin response to oral glucose was evident, with the upper tertile of the 2-h insulin response six times higher than the lower tertile (113 +/- 43 vs. 19 +/- 8 mU/L). Hyperinsulinemia showed a strong, positive association with impaired glucose tolerance, body mass index, waist-to-hip ratio, cholesterol, and triglyceride levels and a negative association with high-density lipoprotein cholesterol levels. Cholesterol levels were on average 0.5 mM higher in men than in women. Deteriorations in carbohydrate and lipid metabolism occurred before 40 yr of age: diabetes, body mass index, waist-to-hip ratio, and fasting triglycerides and cholesterol concentrations peaked and high-density lipoprotein cholesterol concentrations reached their nadir at the end of the fourth decade. CONCLUSIONS - These data suggest that any intervention programs developed to prevent or reduce diabetes prevalence in this population should be targeted at adolescents and young adults.