Does microalbuminuria predict diabetic nephropathy?

OBJECTIVE - To describe risk factors associated with microalbuminuria (MA) in subjects with diabetes. investigate the predictive value of MA as a mark er of risk for diabetic nephropathy (DN), and define risk factors associate d with the development and progression of MA. RESEARCH DESIGN AND METHODS - We conducted a prospective longitudinal study of 23 diabetic subjects with persistent MA and 209 diabetic subjects witho ut KA who attended diabetes clinics at the University of Michigan Medical C enter in 1989 and 1990. Both ps were examined at baseline and after 7 years . At baseline, urinary albumin-to-creatinine groups ratios were studied in random, first morning, and 24-h urine samples. At follow-up, a 12-h overnig ht urine sample was collected and analyzed for albumin and creatinine. At b aseline, MA was defined by at least two separate urine specimens with album in-to-creatinine ratios between 30 and 299 mug albumin per milligram of cre atinine. RESULTS - MA regressed in 56% of subjects with baseline MA without systemat ic application of corrective measures and developed in 16% of subjects with out baseline MA. The predictive value positive of MA as a marker of risk fo r DN was 43%, and the predictive value negative,was 77%,. In the combined c ohort, the incidence and progression of MA were significantly associated wi th poor glycemic control and duration of diabetes between 10 and 14 years. CONCLUSIONS - MA may not be as sensitive and specific a predictor of DN as previously suggested. Other markers of risk, for DN are needed for optimal clinical management.