Microalbuminuria: marker of vascular dysfunction, risk factor for cardiovascular disease

Based on the data from large single and multi-center clinical trials, including the Heart Outcomes Prevention Evaluation (HOPE) study, it is clear that the presence of microalbuminuria is a signal from the kidney that cardiovascular risk is increased and that vascular responses are altered. This is exemplified by studies that have demonstrated that the compensatory vasodilation seen following relief from prolonged ischemia or infusion of vasodilators such as nitroglycerin is blunted in people with microalbuminuria. Thus, the presence of between 30 and 299 mg/day of albumin in the urine is associated with abnormal vascular responsiveness, which may be the result of more advanced atherosclerosis and not necessarily related to the presence of hypertension or renal disease. Agents known to reduce the rise in microalbuminuria or actually reduce the level of microalbuminuria, such as ACE inhibitors, angiotensin receptor blockers, HMG-CoA reductase inhibitors, beta blockers, non-dihydropyridine calcium channel blockers and diuretics, have all been shown to reduce cardiovascular mortality and in some cases preserve renal function. This article will present an overview of the data that support the assertion that a reduction in the rise of microalbuminuria is a significant consideration in the selection of agents to treat a given risk factor (cholesterol or blood pressure) to a recommended target goal. Achieving such a goal with agents that also impact microalbuminuria will provide for a more complete cardiovascular risk reduction.