Risk factors for the progression of microalbuminuria in Japanese type 2 diabetic patients - a 10-year follow-up study

To clarify risk factors for the progression of microalbuminuria in Japanese type 2 diabetic patients, the longitudinal study for 10 years was conducted on 67 outpatients with type 2 diabetes, who had shown no overt proteinuria at baseline. The urinary albumin index (UAI) has been determined based on the mean of at least two random urine samples each year. Categories were defined as normoalbuminuria (UAI <30.0 mg/g.Cr.), microalbuminuria (30.0 less than or equal to UAI < 300.0), and macroalbuminuria (UAI greater than or equal to 300.0). Progression was defined as worsening of the category and/or more than doubling of the baseline UAI value. Multiple logistic regression analysis was performed using age, duration of diabetes, HbA(1c), blood pressure, BMI, serum lipids, smoking habits, and alcohol consumption as independent variables and the progression of microalbuminuria as a dependent variable. Age and HbA(1c) were estimated as significant and independent variables. Furthermore, genetic polymorphisms of angiotensin I-converting enzyme (ACE) and angiotensinogen were analyzed to evaluate the genetic contribution. The D/D genotype of ACE was significantly more common in progressors than in non-progressors. These results suggest that glycemic control and age are important risk factors and the D/D genotype of ACE acts as a risk factor for the progression of microalbuminuria in Japanese type 2 diabetic patients. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.