Is it time to change the definition of normal urinary albumin excretion?

Abstract

This Practice Point commentary discusses a recent study by Forman et al. that examined the association between baseline urinary albumin:creatinine ratio and the risk of developing hypertension among 2,179 women in the first and second Nurses' Health Studies who did not have hypertension or diabetes at baseline and had normoalbuminuria by conventional definitions. The study showed that quartiles of albuminuria beyond the lowest quartile were increasingly predictive of subsequent hypertensive disease, even at levels well below what is conventionally considered to be the normal range. This commentary highlights the importance of evaluating albuminuria as an indicator of target organ damage and a risk factor for cardiovascular disease. Patients without hypertension, diabetes or other cardiovascular diseases who have albuminuria should be considered at risk of cardiovascular disease and should undergo intensive follow-up. In addition, although previous studies have indicated that cardiovascular risk increases exponentially with increasing levels of albuminuria, the definition of the threshold for albuminuria should be dependent on concomitant cardiovascular disease (i.e. lower levels of albuminuria should be considered pathologic if concomitant cardiovascular disease is not present).