To assess the degree of interindividual variation in the rate of progression of microalbuminuria and to identify determinants of progression of microalbuminuria in patients with NIDDM.
In a prospective cohort study, 58 microalbuminuric NIDDM patients were followed for a period of at least 24 months. During this period, the level of microalbuminuria in these patients was assessed in triplicate 24-h urine samples on at least four separate visits. All patients had stable metabolic control and controlled blood pressure during follow-up. Microalbuminuria was defined as an albumin-to-creatinine ratio in 24-h urine of between 3 and 30 mg/mmol. The individual rates of progression of microalbuminuria were calculated from linear regression analysis. At baseline, the following data were collected for all patients: age, sex, ethnicity, time since diagnosis of NIDDM, smoking habits, drug use, blood pressure, BMI, HbA1c, serum creatinine, cholesterol, triglyceride, and HDL cholesterol concentrations.
Microalbuminuria was found to progress linearly in time. Considerable differences in rates of progression of microalbuminuria were found, the absolute yearly change in albumin-to-creatinine ratio ranging from −5.2 to 12.9 mg/mmol. In bivariate analyses, serum triglyceride concentration, use of ACE inhibitors, mean arterial blood pressure, HDL cholesterol, and time since diagnosis of NIDDM correlated with progression of microalbuminuria (P ≤ 0.05). In stepwise multiple regression analysis, a high triglyceride-to–HDL cholesterol ratio at baseline (P = 0.006) and the use of ACE inhibitors (P = 0.007) were identified as the only independent predictors of progression of microalbuminuria.
The rate of progression of microalbuminuria in NIDDM differs considerably between subjects. Diabetic dyslipidemia (high serum triglyceride and low HDL cholesterol) is a predictor of more rapid progression of microalbuminuria in patients with well-controlled blood pressure.