A meta-analysis and systematic review of randomized clinical trials on the effect of coffee consumption on heart rate

Resting heart rate (HR) is increasingly recognized as an indicator of disease and overall morbidity and mortality. Whether chronic coffee consumption affects resting HR is an important consideration for individual consumers as well as from a public health perspective.A meta-analysis of randomized controlled trials (RCTs) was conducted to examine the effectiveness of coffee consumption on resting HR.Original RCTs assessing the effect of coffee consumption on resting HR and published prior to March 2023 were identified by searching online databases, including PubMed, Web of Science, and Cochrane Library databases.Data searches and extraction and risk-of-bias assessments were performed according to the Cochrane guidelines, and the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews were followed. Data on study characteristics, type, and amount of coffee and net change and measurement resting HR were extracted. A random-effects or a fixed-effects model was used to estimate the pooled effect sizes. Homogeneity was determined with the Cochran Q test, and publication bias was assessed through Begg's test, Egger's test, and funnel plots.A total of 6 RCTs with 11 intervention trials or arms involving 485 individuals were included. The participants were generally healthy, although some had hypertension, hypercholesterolemia, or were overweight. The trial duration ranged from 2 weeks to 24 weeks. The overall pooled analysis showed that coffee consumption resulted in a negligible increase in resting HR of 0.40 beats per minute (95% CI: -0.78 to 1.57; P = 0.506), which was statistically insignificant. Subgroup analysis of all specified categories was consistent with the overall analysis. No heterogeneity was observed among included trials (I2 = 0.0%, P = 0.756).The results of the present meta-analysis study demonstrate that daily coffee consumption of 3 to 6 cups for a period of 2 to 24 weeks has no statistically significant effect on resting HR.