Albuminuria as a marker of the risk of developing type 2 diabetes in non-diabetic Aboriginal Australians

BACKGROUND: Aboriginal Australians experience a higher risk of diabetes than the general Australian population. In this paper, we conducted a nested case-control study to determine whether the presence of microalbuminuria and macroalbuminuria is associated with the development of diabetes among diabetes-free Aboriginal people at baseline. METHODS: Urine albumin to creatinine ratios (ACRs) were obtained from 882 Aboriginal people aged 20-74 years from one community. Among them 750 were free of either clinical known diabetes or newly diagnosed diabetes according to WHO 1999 criteria. Over an 11 year follow-up period, 117 participants developed diabetes. They were defined as cases. Each case was matched by an individual control with same sex and body mass index (BMI) category, and age within 2 years. Conditional logistic regression was used to assess the association between albuminuria and diabetes. RESULTS: The baseline level of ACR was significantly higher among cases than among controls. The odds ratios for future diabetes were 2.36 [95% confidence interval (95% CI) 1.01-5.50] and 3.27 (95% CI 1.38-7.77) for middle and upper tertiles, respectively, with adjustment for age, BMI, serum total cholesterol, serum C-reactive protein values, and fasting plasma glucose at the baseline. The adjusted odds ratios were 1.90 (95% CI 0.88-4.06) and 2.51 (95% CI 1.08-5.87) for those with microalbuminuria and macroalbuminuria, respectively. CONCLUSIONS: The presence of microalbuminuria and macroalbuminuria predicts diabetes independent of other known risk markers of development of type 2 diabetes in Aboriginal people.