Association of Urinary Sodium Excretion with Vascular Damage: A Local Kidney Effect, Rather Than a Marker of Generalized Vascular Impairment

Abstract EN

Evidence suggests that increased salt consumption induces blood pressure- (BP) mediated organ damage, yet it remains unclear whether it reflects a generalized micro- and macrovascular malfunction independent of BP.

We studied 197 newly diagnosed and never-treated individuals with hypertension, intermediate hypertensive phenotypes, and normal BP, classified by use of 24-hour ambulatory BP monitoring.

Sodium excretion and microalbuminuria were estimated in 24-hour urine samples, dermal capillary density was estimated from capillaroscopy, and arterial stiffness was estimated with pulse wave velocity (PWV) and augmentation index (AIx).

Sodium excretion correlated with microalbuminuria (p<0.001) and 24-hour and day- and nighttime systolic BP, but not with office blood pressure, arterial stiffness, or capillary density.

In the multivariate analysis, the association with microalbuminuria was maintained (p=0.007).

In a population free from the long-standing effects of hypertension, increased salt intake appears to be associated with early signs of vascular kidney damage, rather than a diffuse micro- and macrovascular impairment.