New insights into the significance of microalbuminuria

This review summarizes recent work that has explored the association between microalbuminuria and adverse clinical outcomes in the presence and absence of diabetes.

Recent investigations have documented the prevalence of microalbuminuria in the general community and have also highlighted the continuous relationship between the level of urinary albumin excretion and clinical endpoints. Even below traditional microalbuminuria thresholds, urinary albumin levels appear to correlate with clinical outcomes. Microalbuminuria is becoming increasingly recognized as an independent risk factor for cardiovascular morbidity and mortality. At least for subjects with type 2 diabetes and microalbuminuria, intensive, multifactorial interventions can reduce the risk of cardiovascular events by about 50%. Although several studies have found an association between microalbuminuria and surrogate measurements of vascular disease, the exact molecular mechanisms linking an increase in urinary albumin excretion and vascular disease are still unknown. Microalbuminuria also has a well-documented association with progressive diabetic renal disease but recent studies have suggested that the prognostic significance of microalbuminuria in this regard may not be as powerful as originally reported.

Aggressive, multifactorial interventions, including the use of drugs that interrupt the renin-angiotensin system are strongly recommended for patients with diabetes and micro-albuminuria to ameliorate the progression of renal and vascular complications. This approach should also possibly apply to microalbuminuric subjects without diabetes. The relationship between microalbuminuria and progressive diabetic renal disease requires re-evaluation given temporal trends in the prevention and treatment of diabetic complications.