Central obesity is an independent risk factor for albuminuria in nondiabetic South Asian subjects.

OBJECTIVE: South Asians have a high prevalence of central obesity. When the diagnosis of diabetes is made, they have a very high risk of developing renal failure. In the current study, we explored the hypothesis that central obesity is associated with the development of renal injury, before the manifestation of diabetes. RESEARCH DESIGN AND METHODS: We invited first-degree nondiabetic relatives of South Asian type 2 diabetic patients for investigation of microalbuminuria and diabetes. Subjects who used antihypertensive or antidiabetic medication were excluded. We performed a glucose tolerance test according to the classic World Health Organization criteria. A total of 205 subjects were normoglycemic; we excluded 25 subjects because of impaired glucose tolerance, and 30 subjects were excluded because of de novo diabetes. Central obesity was measured by waist-to-hip ratio (WHR). Albuminuria was measured as albumin-to-creatinine ratio (ACR) in the early-morning urine.
RESULTS: Central obesity was independently related with albuminuria in the 205 normoglycemic subjects. We found no relation of fasting blood glucose or systolic blood pressure with albuminuria. Multivariate analysis for the presence of increased albuminuria (median ACR >0.31 mg/mmol) showed a relative risk of 4.1 for the highest versus the lowest tertile of WHR (P = 0.002).
CONCLUSIONS: Central obesity is an early and independent risk factor for increased albuminuria in normoglycemic South Asian subjects. This could explain the high incidence of diabetic renal disease in South Asians, probably by the mechanism of insulin resistance and endothelial dysfunction in the pre-diabetic state.