Abstract

Objectives Dedicated studies aimed at investigating the relationship between walking pace and arrhythmia are limited. This study assessed associations between self-reported and accelerometer measured walking pace and incident cardiac arrhythmias, overall and by subtype, and explored metabolic and inflammatory markers as possible mediators. Methods Self-reported average walking pace was available for 420 925 UK Biobank participants, and accelerometer measured time spent walking at different paces was available for 81 956 participants. Outcomes were incident cardiac arrhythmias: all, atrial fibrillation (AF), other (including bradyarrhythmias and ventricular arrhythmias), bradyarrhythmias and ventricular arrhythmias. Cox proportional regression models were used to investigate the associations. Results Compared with slow walking pace, average and brisk walking pace were associated with significantly lower risks of all cardiac arrhythmias (hazard ratio (HR) 0.65, 95% confidence interval (CI) 0.62 to 0.68; HR 0.57, 95% CI 0.54 to 0.60), AF (HR 0.62, 95% CI 0.58 to 0.65; HR 0.54, 95% CI 0.50 to 0.57) and other arrhythmias (HR 0.69, 95% CI 0.64 to 0.73; HR 0.61, 95% CI 0.57 to 0.65). Overall, 36.0% of the association between walking pace and all arrhythmias was mediated via metabolic and inflammatory markers. The associations were stronger in women, in those aged <60 years, in those with a body mass index <30, in those who had hypertension and in those with >= 2 long term conditions. Conclusions Average and brisk self-reported walking pace and time spent walking at moderate and brisk pace were associated with a decreased risk of cardiac arrhythmias, in part mediated via metabolic and inflammatory pathways. Our findings suggest brisk walking may be a safe and effective exercise to reduce arrhythmias, especially for higher risk groups.