Initial urinary albumin excretion determines the progression of microalbuminuria in patients with type-2 diabetes and normotensive blood pressure values despite improved metabolic control

Abstract

Persistent increased urinary albumin excretion rate (UAER) is associated with increased cardiovascular mortality in type-2 diabetes, however, there are no conclusive data about the progression of advanced UAER in these patients. The present study has investigated the effect of metabolic intervention on the progression in UAER in relation to initial UAER levels. A total of 20 patients with type-2 diabetes and secondary failure to sulfonylurea were observed during 1 year (age, 60±8 years; HbA 1c, 10.8±1.4%; and duration of diabetes, 17±10 years) and divided into two groups: group 1 ( n=10; UAER: 51±35 mg/24 h); and group 2 ( n=10; UAER: 191±175 mg/24 h). Despite a significant improvement of metabolic control by insulin treatment in both groups (HbA 1c: group1: 11±1.5 vs. 7.9±1.2%; group 2: 10.6±0.9 vs. 9.1±1.3%, P<0.001), a progression of UAER was observed in group 2 (191±175 vs. 331±237 mg/24 h, P<0.02), but not in group 1 (51±35 vs. 41 + ̄ 24 mg/24 h). Still serum creatinine levels remained normal in all patients during the observation period. The 24 h blood pressure (RR) values in the two groups remained normal under antihypertensive therapy throughout the study (group 1: RR syst: 130 vs. 136 mmHg; RR diast: 80 vs. 81 mmHg, mean arterial pressure (MAD): 89 vs. 93 mmHg; group 2: RR syst: 139 vs. 134 mmHg; RR diast: 78 vs. 75 mmHg, MAD: 97 vs. 90 mmHg). The data shows that in type-2 diabetic patients with normotensive blood pressure values the initial urinary albumin excretion levels determine the progression of UAER. When metabolic control is improved incipient UAER remains constant, but advanced UAER shows progression.