Current smoking is associated with a 0.36 beats per minute higher resting heart rate for each additional copy of the smoking increasing allele rs16969968/rs1051730 in current smokers.
Meta-Analysis (n=141,317)
Yes
Does smoking heaviness causally increase blood pressure and resting heart rate in adults?
Mendelian randomization suggests that smoking heaviness causally increases resting heart rate but does not directly alter blood pressure, indicating that smoking's cardiovascular risk may partly operate through elevated heart rate.
Effect estimate: beta-coefficient 0.36 (95% CI 0.18; 0.54)
p-value: p=<0.001
Background— Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. Methods and Results— Data on 141 317 participants (62 666 never, 40 669 former, 37 982 current smokers) from 23 population-based studies were included in observational and Mendelian randomization meta-analyses of the associations of smoking status and smoking heaviness with systolic and diastolic blood pressure, hypertension, and resting heart rate. For the Mendelian randomization analyses, a genetic variant rs16969968/rs1051730 was used as a proxy for smoking heaviness in current smokers. In observational analyses, current as compared with never smoking was associated with lower systolic blood pressure and diastolic blood pressure and lower hypertension risk, but with higher resting heart rate. In observational analyses among current smokers, 1 cigarette/day higher level of smoking heaviness was associated with higher (0.21 bpm; 95% confidence interval 0.19; 0.24) resting heart rate and slightly higher diastolic blood pressure (0.05 mm Hg; 95% confidence interval 0.02; 0.08) and systolic blood pressure (0.08 mm Hg; 95% confidence interval 0.03; 0.13). However, in Mendelian randomization analyses among current smokers, although each smoking increasing allele of rs16969968/rs1051730 was associated with higher resting heart rate (0.36 bpm/allele; 95% confidence interval 0.18; 0.54), there was no strong association with diastolic blood pressure, systolic blood pressure, or hypertension. This would suggest a 7 bpm higher heart rate in those who smoke 20 cigarettes/day. Conclusions— This Mendelian randomization meta-analysis supports a causal association of smoking heaviness with higher level of resting heart rate, but not with blood pressure. These findings suggest that part of the cardiovascular risk of smoking may operate through increasing resting heart rate.
Linneberg et al. (Thu,) conducted a meta-analysis in Cardiovascular disease risk associated with smoking (n=141,317). Smoking status vs. Never smoking was evaluated on Resting heart rate increase associated with smoking heaviness (beta-coefficient 0.36, 95% CI 0.18; 0.54, p=<0.001). Current smoking is associated with a 0.36 beats per minute higher resting heart rate for each additional copy of the smoking increasing allele rs16969968/rs1051730 in current smokers.