Effect of sodium and potassium supplementation on vascular and endothelial function: a randomized controlled trial.
What this study found
Adding potassium to the high-sodium meal attenuated the postprandial decline in endothelial function. The largest between-meal difference in flow-mediated dilatation occurred at 30 minutes, when FMD differed by -3.58 ± 0.85%, and the potassium-containing meal blunted the sodium-associated reduction in FMD. Potassium also altered low-flow-mediated constriction, while the meals did not differ significantly for central augmentation index, pulse wave velocity, or blood pressure over time. Serum potassium rose after the HKHN meal, with a maximum increase of 0.6 ± 0.3 mmol/L at 90 minutes,…
- Study & population
- Healthy normotensive adults in Australia were studied in a randomized crossover design.
- Intervention
- This randomized crossover trial compared a single oral high-potassium, high-sodium meal with a low-potassium, high-sodium meal.
- Key limitation
- The trial tested only acute, single-meal effects, so long-term cardiovascular implications remain unknown.
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Open PDFOriginal abstract
BACKGROUND It is known that increased potassium and reduced sodium intakes can improve postprandial endothelial function. However, the effect of increasing potassium in the presence of high sodium in the postprandial state is not known. OBJECTIVE We aimed to determine the effect of high potassium and high sodium on postprandial endothelial function as assessed by using flow-mediated dilatation (FMD) and arterial compliance as assessed by using pulse wave velocity (PWV) and central augmentation index (AIx). DESIGN Thirty-nine healthy, normotensive volunteers [21 women and 18 men; mean ± SD age: 37 ± 15 y; BMI (in kg/m(2)): 23.0 ± 2.8] received a meal with 3 mmol K and 65 mmol Na (low-potassium, high-sodium meal (LKHN)], a meal with 38 mmol K and 65 mmol Na [high-potassium, high-sodium meal (HKHN)], and a control meal with 3 mmol K and 6 mmol Na (low-potassium, low-sodium meal) on 3 separate occasions in a randomized crossover trial. Brachial artery FMD, carotid-femoral PWV, central AIx, and blood pressure (BP) were measured while participants were fasting and at 30, 60, 90, and 120 min after meals. RESULTS Compared with the LKHN, the addition of potassium (HKHN) significantly attenuated the postmeal decrease in FMD (P-meal by time interaction < 0.05). FMD was significantly lower after the LKHN than after the HKHN at 30 min (P < 0.01). AIx decreased after all meals (P < 0.05). There were no significant differences in AIx, PWV, or BP between treatments over time. CONCLUSION The addition of potassium to a high-sodium meal attenuates the sodium-induced postmeal reduction in endothelial function as assessed by FMD. This trial was registered at http://www.anzctr.org.au/ as ACTRN12613000772741.