Prognostic significance of microalbuminuria

Diabetic nephropathy is the only increasing cause of renal failure in the Western world. It affects a large proportion of both insulin-dependent (IDDM) and non-insulin-dependent diabetic (NIDDM) patients. A critical stage in the development of diabetic renal disease is the onset of microalbuminuria, defined as an albumin excretion rate of 30 to 300 mg/day. Microalbuminuria predicts progression to renal failure and early cardiovascular mortality in both IDDM and NIDDM patients. Microalbuminuria is associated with a constellation of other risk factors for small and large vessel damage which include raised blood pressure, poor glycemic control, plasma lipid and clotting factor abnormalities, left ventricular hypertrophy, and insulin resistance. Treatment with angiotensin-converting enzyme inhibitors corrects microalbuminuria and prevents progression to persistent proteinuria. Good blood glucose control significantly reduces the risk of progression from normoalbuminuria to microalbuminuria. The treatment of microalbuminuria appears highly cost-beneficial and substantially increases life expectancy. The development of microalbuminuria, for which all diabetic patients aged 12 to 70 years should be screened, should alert the physician to set in motion a program of assessment, monitoring, and correction of all risk factors for renal and cardiovascular disease.