Potassium supplementation and heart rate: A meta-analysis of randomized controlled trials

•Little is known about the effect of increased potassium intake on heart rate.•We summarized 22 trials of potassium supplementation and heart rate in a meta-analysis.•Potassium doses of 0.9-4.7 g/d for 2-24 weeks changed heart rate by 0.2 bpm (95% CI: −0.4, 0.8).•Doubling the intake of potassium is unlikely to affect heart rate in healthy adults.

Background and aimsIncreasing the intake of potassium has been shown to lower blood pressure, but whether it also affects heart rate (HR) is largely unknown. We therefore assessed the effect of potassium supplementation on HR in a meta-analysis of randomized controlled trials.Methods and resultsWe searched PubMed (1966-October 2014) for randomized, placebo-controlled trials in healthy adults with a minimum duration of two weeks in which the effect of increased potassium intake on HR was assessed. In addition, reference lists from meta-analysis papers on potassium and blood pressure were hand-searched for publications. Two investigators independently extracted the data. We performed random effects meta-analyses, subgroup and meta-regression analyses for characteristics of the study (e.g. design, intervention duration, potassium dose and salt type, change in potassium excretion, sodium excretion during intervention) and study population (e.g. gender, age, hypertensive status, pre-study HR, pre-study potassium excretion). A total of 22 trials (1086 subjects), with a median potassium dose of 2.5 g/day (range: 0.9-4.7 g/day), and median intervention duration of 4 weeks (range: 2-24 weeks) were included. The meta-analysis showed no overall effect of increased potassium intake on HR (0.19 bpm, 95% CI: −0.44, 0.82). Stratified analyses yielded no significant effects of potassium intake on HR in subgroups, and there was no evidence for a dose-response relationship in meta-regression analyses.ConclusionA chronic increase in potassium intake with supplemental doses of 2-3 g/day is unlikely to affect HR in apparently healthy adults.