Microalbuminuria in essential hypertension

Microalbuminuria (urinary albumin excretion equal to 30-300mg/24h) is a reliable indicator of premature cardiovascular mortality in diabetic patients and in the general population. In insulin-dependent and non-insulin-dependent diabetes mellitus microalbuminuria Is a marker of initial diabetic nephropathy and predicts the evolution toward renal insufficiency. In essential hypertension the clinical and prognostic role of microalbuminuria is more controversial. While it is a recognised marker of cardiovascular complications and a reliable predictor of ischaemic heart disease, its prognostic value on the risk of progressive renal alterations is still uncertain because no prospective studies, taking microalbuminuria as a selection criterion and renal Insufficiency as an end point, are available. Blood pressure control with anti hypertensive drugs is accompanied by a reduction in urinary albumin excretion. The favourable effects of anti hypertensive agents on microalbuminuria appear to be proportional to blood pressure reduction, but anglotensin-converting enzyme inhibitors and angiotensin-II-receptor antagonists show an additional beneficial effect on urinary albumin excretion. Whether the reduction of microalbuminuria obtained through pharmacological intervention has favourable prognostic implications remain to be demonstrated. However, screening for microalbuminuria is a relatively easy and inexpensive procedure and reveals a potentially treatable abnormality. Thus, considering that microalbuminuria identifies hypertensive subjects at higher risk than standard, urinary albumin excretion should be routinely measured in hypertensive patients and, in the presence of microalbuminuria, antihypertensive treatment should be intensified in order to obtain an optimal blood pressure control.