Microalbuminuria as a Prognostic Marker in Essential Hypertension

Essential hypertension is a major cardiovascular pathology globally, with an estimated prevalence of approximately 33%, and it is a significant contributor to both mortality and adverse cardiovascular events. Finding early prognostic markers in such individuals could, thus, provide enhanced risk stratification and identification of patients with higher odds of target-organ damage or adverse events. Microalbuminuria is defined as an abnormal excretion of albumin in urine, is well associated with vascular disease, endothelial dysfunction, and low-grade inflammation, and is a marker of subclinical renal damage. Through the years, microalbuminuria at baseline has been well correlated with increasing blood pressure levels and blood pressure patterns, i.e., non-dipping phenotype. At the same time, its presence in hypertensive individuals indicated increased rates of mortality, renal disease progression, and major adverse cardiovascular outcomes, including stroke and myocardial infarction. Thus, microalbuminuria can provide a prognostic marker of future adverse events in hypertensive individuals. Interestingly, standard antihypertensive pharmacotherapy and newer drugs have shown regression of microalbuminuria extent and renoprotection in both diabetic as well as hypertensive individuals, implying that early therapy could decrease the rate of disease progression and limit target-organ damage. Thus, the aim of this review is to analyze the available studies documenting the predictive role of microalbuminuria for both mortality, target- organ damage, and adverse events, as well as describe the impact of pharmacotherapy in the presence and extent of subclinical renal damage, as shown by the levels of this marker.