Increased levels of urinary albumin: A cardiovascular risk factor and a target for treatment

Abstract

Excretion of albumin in the urine is highly variable, ranging from nondetectable quantities to grams. Increased levels of albuminuria are highly prevalent in healthy individuals and even more so in hypertensive and diabetic populations. The variable excretion of albumin in the urine is related to the risk for the individual to develop cardiovascular disease (CVD): absence or very low levels of albuminuria is associated with low risk, whereas the risk continuously increases (with no thresholds) with increasing amount of urinary albumin. The predictive power of urinary albumin levels for CVD risk is independent of other CVD risk factors. Leakage of albumin appears to be associated with a defect in vascular permeability, most likely caused by a defect in the glycocalyx layer. This defect appears to be not only present in the kidneys but also in other vascular beds, providing a potential explanation as to why increased albuminuria not only predicts renal disease risk but also CVD risk. Treatments that lower albuminuria are associated with cardiovascular protection, as demonstrated in randomized controlled trials of diabetic as well as hypertensive patients. There is preliminary evidence that albuminuria lowering also protects healthy individuals with elevated albumin excretion rates. In conclusion, albuminuria appears to be a sensitive marker for the susceptibility of an individual to develop CVD. Lowering albuminuria appears to be associated with cardiovascular protection.-It may therefore be a suitable target for early primary prevention using cardiovascular protective therapy regimens. © 2010 Springer-Verlag Milan.