Nephropathy affects about one third of diabetic patients and its onset can be predicted almost a decade in advance by detecting small quantities of albumin in the urine (microalbuminuria). Thus, detection of proteinuria or microalbuminuria in diabetic patients carries important implications and merits intervention. Strategies for delaying the relentless progression of microalbuminuria to diabetic nephropathy and ultimately end-stage renal failure are focused on improving glycemic control and reducing blood pressure. Studies with beta-blockers, calcium antagonists, diuretics, and angiotensin-converting enzyme (ACE) inhibitors in hypertensive diabetics with microalbuminuria have shown a significant reduction in urinary albumin excretion rates (AER), with effective lowering of blood pressure. In a crossover study, we compared the effects of captopril versus indapamide as monotherapy for 12 weeks on AER and blood pressure in 31 diabetic patients with established microalbuminuria. The 2 drugs were equally effective in reducing AER (average reduction 30-40%) and had comparable antihypertensive effects.