High Dietary Sodium Reduces Flow Mediated Dilation Similarly in Humans with Salt Sensitive & Salt Resistant Blood Pressure

Abstract

Recent studies demonstrate that high dietary sodium (HS) impairs endothelial function in those with salt‐resistant (SR) blood pressure (BP), suggesting that the effect of dietary sodium on endothelial function may be independent of BP. We hypothesized that HS would impair flow mediated dilation (FMD) more in those with salt sensitive (SS) BP compared to those with SR BP. Five SS (2M 3W, 43±5yrs) & 7 SR (3M 4W, 45±2.4yrs) subjects were enrolled in a controlled feeding study consisting of a run‐in diet followed by a two phase randomized crossover 7‐day diet perturbation: low dietary sodium (LS) (20 mmol/d) & HS (300 or 350 mmol/d). Brachial artery FMD and 24‐hr BP were assessed on the last day of each diet. SS BP was defined as a change in 24‐hr mean arterial pressure of >; 5 mmHg between LS & HS diets. HS attenuated FMD in both the SS (LS: 12.8±2.4%, HS: 8.2±1.4%, p<0.05) & SR (LS: 10.5±1.8%, HS: 6.9±1.1%, p<0.05) groups. The decline in FMD was not different between groups for the change in FMD (SS: Δ‐4.6±1.2%, SR: Δ‐3.6±1.2%, p>;0.05). These data indicate a HS diet impairs FMD to a similar extent in SS & SR individuals, providing additional evidence suggesting a BP independent effect of dietary sodium on endothelial function.Research funded by NIH grants 2 P20 RR016472–11 & R01 HL104106.