Microalbuminuria, insulin resistance, diabetes, hypertension, and kidney function: the latest concepts in pathology and pharmacologic treatment.

Microalbuminuria-increased urinary albumin excretion undetectable by traditional urinary dipstick-has been associated with insulin resistance, diabetes mellitus, obesity, and hypertension. It is also a powerful predictor for heart disease and all-cause mortality. In diabetic patients, microalbuminuria has been correlated with the progression of diabetic nephropathy and the development of renal insufficiency. Furthermore, its correlation with markers of inflammation such as C-reactive protein suggests that microalbuminuria may indicate generalized endothelial dysfunction rather than isolated nephropathy. Drugs that block the renin-angiotensin system, such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs), have been shown to reduce albuminuria, resulting in renal protection. Recently, dualaction beta-adrenergic blockers such as carvedilol have been shown to exert favorable effects on albuminuria in diabetic patients with hypertension. Insulin resistance reflects a predictable risk for diabetes, and there appears to be a good correlation between insulin resistance, albuminuria, and progression of renal disease in diabetes with or without hypertension. As in microalbuminuria, ACE inhibitors, ARBs, and dual-action beta-blockers help improve insulin sensitivity.