Microalbuminuria as a risk factor: the influence of renin-angiotensin system blockade.

Microalbuminuria, the increase in urinary albumin excretion, has most often been linked with renal disease in diabetic patients. However, accumulating data demonstrate a link between albuminuria and cardiovascular disease in both diabetic and nondiabetic patients, even at very low levels of urinary albumin excretion once considered to be 'normal'. The reasons for the increase in cardiovascular risk may be linked to generalized vascular and endothelial dysfunction, mediated by the renin-angiotensin system and the angiotensin II type 1 receptor. Accordingly, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers have demonstrated some success in treating microalbuminuria. With the prevalence of microalbuminuria at around 7% in the general population, and as high as 39% in diabetic patients, reducing and preventing microalbuminuria is becoming of increasing interest in helping to reduce cardiovascular risk. Subsequently, international guidelines have recommended screening for the presence of microalbuminuria in all patients with hypertension, diabetes or both.