Effect of potassium supplementation on vascular function: A meta-analysis of randomized controlled trials

Background: Effects of potassium supplementation on vascular function remain conflicting. This meta-analysis aimed to summarized current literature to fill the gaps in knowledge. Methods: A literature search was performed on PubMed database through April, 2016. The measurements of vascular function included pulse wave velocity (PWV), augmentation index (AI), pulse pressure (PP), flow mediated dilatation (FMD), glycerol trinitrate responses (GTN), and intercellular cell adhesionmolecule-1 (ICAM-1). Data were pooled as standardized mean difference (SMD) with 95% confidence intervals. Results: Seven randomized controlled trials examining 409 participants were included, with dosage of potassium ranging from 40 to 150 mmol/day, and duration of intervention from 6 days to 12 months. Pooling results revealed a significant improvement in PP (SMD - 0.280, 95% CI - 0.493 to -0.067, p - 0.010), but no improvement in PWV (SMD - 0.342, 95% CI - 1.123 to 0 . 440, p = 0.391), AI (SMD - 0.114, 95% CI - 0.282 to 0.054, p = 0.184), FMD (SMD 0.278, 95% CI - 0.321 to 0.877, p = 0.363), GTN (SMD - 0.009, 95% CI - 0.949 to 0.930, p = 0.984), and ICAM-1 (SMD - 0.238, 95% CI - 0.720 to 0.244, p = 0.333). Conclusions: Potassium supplementation was associated with significant improvement of PP, rather than other measurements of vascular function. However, the small number of researches and wide variation of evidences make it difficult to make a definitive conclusion. (C) 2016 Elsevier Ireland Ltd. All rights reserved.