Effect of antidiabetic medications on microalbuminuria in patients with type 2 diabetes

The progression of diabetes and hypertension complications is associated with microalbuminuria. Intensive glycemic control prevents or retards microalbuminuria in patients with type 2 diabetes, but little is known about the respective benefits of different antidiabetic drugs. We studied the effect of gliclazide and pioglitazone on microalbuminuria in patients with type 2 diabetes. We excluded patients with very poor glycemic control (glycated hemoglobin [HbA(1c)] >10%), impaired liver function, nondiabetic renal diseases, and those whose urine contained red blood cells, hemoglobin, or casts. Each patient received the designated drug for 12 weeks and their body weight, blood pressure (BP), fasting plasma glucose (FPG), HbA(1c), lipids (triglycerides [TG], total, and high-density lipoprotein-cholesterol [HDL-C]), 1,5 anhidroglucitol (1,5-AG), immunoreactive insulin (IRI), and urinary albumin to creatinine ratio (UACR) were measured every month. The effects of the drugs were analyzed using 2-way repeated measures analysis of variance (ANOVA). The 2 groups of patients were well matched for age, duration of diabetes, retinal status, blood pressure, body mass index (BMI), IRI, FPG, HBA(1c), 1,5-AG, lipids, and UACR, as well as the use of antihypertensive drugs. After treatment, no significant differences were seen in drug efficacy between the 2 groups. Gliclazide and pioglitazone significantly reduced FPG (F = 26.0, P <.0001), HBA(1c) (F = 48.1, P <.0001), and total cholesterol (TC) levels (F = 3.5, P <.05). Decrements in these metabolic parameters were comparable between the groups. 1,5-AG increased in both groups (F = 27.5, P <.0001), and the increment was comparable in both groups. Gliclazide and pioglitazone significantly reduced UACR (F = 15.7, P <.0001) with a comparable decrement in both groups. No other variables changed significantly throughout the 12-week treatment. These results suggest that 12 weeks of treatment with gliclazide or pioglitazone are equally effective in reducing microalbuminuria with similar improvements in blood glucose and cholesterol levels, independent of their mechanisms of actions.