Effect of intensive glycemic control on microalbuminuria in type 2 diabetes

OBJECTIVE - Microalbuminuria can reflect the progress of microvascular comp lications and may be predictive of macrovascular disease in type 2 diabetes . The effect of intensive glycemic control on microalbuminuria in patients in the U.S. who have had type 2 diabetes for several years has not previous ly been evaluated. RESEARCH DESIGN AND METHODS - We randomly assigned 153 male patients to eit her intensive treatment (INT) (goal HbA(1c) 7.1%) or to standard treatment (ST) (goal HbA(1c) 9.1% P = 0.001), and data were obtained during a 2-year period. Mean duration of known diabetes was 8 years, mean age of the patien ts was 60 years, and patients were well matched at baseline. We obtained 3- h urine samples for each patient at baseline and annually and defined micro albuminuria as an albumin:creatinine ratio of 0.03-030. All patients were t reated with insulin and received instructions regarding diet and exercise. Hypertension and dyslipidemia were treated with similar goals in each group . RESULTS - A total of 38% of patients had microalbuminuria at entry and were evenly assigned to both treatment groups. INT retarded the progression of microalbuminuria during the 2-year period: the changes in albumin:creatinin e ratio from baseline to 2 years of INT versus ST were 0.045 vs. 0.141, res pectively (P = 0.046). Retardation of progressive urinary albumin excretion was most pronounced in those patients who entered the study with microalbu minuria and were randomized to INT. Patients entering with microalbuminuria had a deterioration in creatinine clearance at 2 years regardless of the i ntensity of glycemic control. In the group entering without microalbuminuri a, the subgroup receiving ST had a lower percentage of patients with a macr ovascular event (17%) than the subgroup receiving INT (36%) (P = 0.03). Use of ACE inhibitors or calcium-channel blockers was similarly distributed am ong the groups. CONCLUSIONS - Intensive glycemic control retards microalbuminuria in patien ts who have had type 2 diabetes for several years but may not lessen the pr ogressive deterioration of glomerular function. Increases in macrovascular event rates in the subgroup entering without albuminuria who received INT r emain unexplained but could reflect early worsening, as observed with micro vascular disease in the Diabetes Control and Complications Trial.