Examining postprandial endothelial function following meals varying in sodium and potassium content in healthy young females

High sodium diets are a major contributor to cardiovascular disease burden. Excess dietary sodium impairs endothelial function, which is the first step in the future development of atherosclerosis and hypertension. Increasing potassium intake is shown to improve endothelial function and may even counteract the deleterious effects of a high sodium diet. Endothelial function is shown to be impaired even after a single high-sodium meal; increasing the potassium content of a high-sodium meal may counteract sodium-induced endothelial dysfunction. However, the effects in young females, who may uniquely benefit from the protective effects of estrogen on the vasculature, are unknown. Our aim is to explore the interactive effects of sodium and potassium on postprandial endothelial function in young females. We hypothesize that a high sodium meal will impair postprandial endothelial function compared to a low sodium meal, but adding potassium to the meal will mitigate sodium-induced impairments. Healthy young females (n=4; age 26±2y, BMI 24.8±6.8kg/m2, BP 107±7/69±10mmHg) consumed three meals in randomized order: a low-sodium (~300mg)/low-potassium (~130mg) meal, a high-sodium (~1500mg)/low-potassium (~130mg) meal and a high-sodium (~1500mg)/high-potassium (~1500mg) meal. Meals were consumed during separate laboratory visits at least one week apart. Endothelial function was assessed via brachial artery flow-mediated dilation (FMD) at baseline and 30, 60, 90, 120, and 180 minutes after meal consumption. Baseline FMD was not different between visits (p=0.49). In our general linear model analyses, there was no significant main effect of time (p=0.43) or meal (p=0.94). The time*meal interaction approached significance (p=0.18). Pairwise comparisons with Bonferroni correction show that after the high-sodium/high-potassium meal, FMD was lower at 30 minutes compared to 180 minutes post-meal (p=0.01) but FMD at all subsequent timepoints was not different (all p >0.05 compared to 180 minutes). After all meals, FMD was not significantly different at 180 minutes compared to baseline (all p >0.05). At 180 minutes, there were no differences in FMD between meals (p=0.26). At each time point, there were no differences in FMD between meals (all p >0.05). These preliminary data provide insight into postprandial changes in endothelial function when varying amounts of sodium and potassium are consumed. This study is ongoing; more data are needed to fully understand the impact of sodium and potassium on vascular health after a single meal. Future analyses will also include comparisons against males and older adults to elucidate age and sex differences. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.