Obesity and changes in urine albumin/creatinine ratio in patients with type 2 diabetes: the DEMAND study.

BACKGROUND AND AIMS: Obesity is a potential risk factor for renal disease in non-diabetic subjects. It remains unclear whether this also applies to diabetic patients. We investigated whether obesity predicted changes in albumin excretion rate in individuals with type 2 diabetes. METHODS AND RESULTS: Fifty Italian diabetes outpatient clinics enrolled a random sample of 1289 patients. A morning spot urine sample was collected to determine urinary albumin/creatinine ratio (ACR) at baseline and after 1 year from the study initiation. Progression of albumin excretion was defined as a doubling in ACR, while regression was defined as a 50% reduction. Multivariate logistic regression analyses were used to evaluate correlates of these outcomes. Data are expressed as odds ratios (OR) with 95% confidence intervals (CI). The risk of progression increased by 7% (OR=1.07; 95%CI 1.00-1.15) for every 5-cm increase in waist circumference measured at baseline, and by 17% (OR=1.17; 95%CI 1.03-1.33) for every one-unit increase in BMI during follow-up. The likelihood of regression was not independently associated with any of the variables investigated. The effect of obesity on progression of ACR was independent of metabolic control, blood pressure, treatment, and baseline level of albumin excretion. CONCLUSIONS: We found a tight link between obesity and changes in albumin excretion in diabetic subjects, suggesting potential benefits of interventions on body weight on end-organ renal damage.