Abstract P324: Effects of Sodium and Potassium Supplementation on Endothelial Function and Inflammation in Untreated (Pre)Hypertensives: A Fully Controlled Dietary Intervention Study

Background: High sodium and low potassium intakes have adverse effects on blood pressure (BP), which increases the risk of cardiovascular and renal diseases. The role of endothelial dysfunction and inflammation in this pathophysiological process is not yet clear.Objectives: In a randomized placebo-controlled crossover study in untreated (pre)hypertensive adults we examined the effects of sodium and potassium supplementation on endothelial function and inflammation.Methods: During the study, subjects were on a fully controlled diet that was relatively low in sodium and potassium. After a one-week run-in period, subjects received capsules with supplemental sodium (3.0 g/d), supplemental potassium (2.8 g/d), or placebo, for four weeks each, in random order. After each intervention, a panel of circulating biomarkers of endothelial function (e.g. nitric oxide, endothelin-1, cellular adhesion molecules) and inflammation (e.g. tumor necrosis factor-α, C-reactive protein, interleukins) were measured. Brachial artery flow-mediated dilation (FMD) and skin microvascular vasomotion were assessed in random subgroups of 22 to 24 subjects.Results: Of 37 randomized subjects, 36 completed the study. They had a mean pre-treatment BP of 145/81 mmHg and 69% had systolic BP ≥140 mmHg. During sodium supplementation serum endothelin-1 was increased by 0.24 pg/ml (95% CI: 0.03, 0.45), but no change was seen in other endothelial or inflammatory biomarkers. FMD and microvascular vasomotion were unaffected by sodium supplementation. Potassium reduced IL-8 levels by 0.28 pg/ml (95% CI: 0.03, 0.53), without affecting the other circulating biomarkers. FMD was 1.16% (95% CI: 0.37, 1.96) higher during potassium supplementation than during placebo, with FMD being improved in 83% (20/24) of the subjects after potassium supplementation. Microvascular vasomotion was unaffected.Conclusions: A four-week increase in sodium intake increased endothelin-1, but had no effect on other markers of endothelial function or inflammation. Increased potassium intake had a beneficial effect on FMD, without affecting circulating endothelial biomarkers. Inflammatory biomarkers, with the exception of IL-8, were unaffected by potassium intake.Trial registration: ClinicalTrials.gov Identifier: [NCT01575041][1] [1]: /lookup/external-ref?link_type=CLINTRIALGOVu0026access_num=NCT01575041u0026atom=%2Fcirculationaha%2F131%2FSuppl_1%2FAP324.atom