Association of calcium supplement with risk of incident arrhythmia.

BACKGROUND AND AIMS: Calcium plays a crucial role in cardiac electrophysiology, but the association between calcium supplement and the risk of incident arrhythmia remains unclear.

OBJECTIVE

To investigate the relationship between habitual calcium supplement and incident risk of cardiac arrhythmia.

METHODS

We conducted a prospective study of 480,972 participants from the UK Biobank. Habitual calcium supplement was treated as the main exposure. The primary outcome was the incidence of arrhythmias, including atrial fibrillation/flutter (AF/AFL), ventricular arrhythmia (VA), and bradyarrhythmia. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

After a median follow-up of 11.69 years, 46,609 incident arrhythmia cases were documented, including 36,406 AF/AFL, 5,370 VA, and 14,226 bradyarrhythmia. After multivariable adjustment, calcium supplement was associated with an increased risk of total arrhythmias (HR 1.11, 95% CI 1.05-1.19), AF/AFL (HR 1.20, 95% CI 1.12-1.28), VA (HR 1.14, 95% CI 1.07-1.21), and bradyarrhythmia (HR 1.18, 95% CI 1.11-1.26). Significant interactions were observed between calcium supplement and estimated glomerular filtration rate, diabetes, cardiovascular disease, and polygenic risk score for AF (all p for interaction < 0.05).

CONCLUSIONS

Calcium supplement was associated with an increased risk of incident arrhythmia. Careful evaluation of the potential arrhythmic risk is warranted when considering calcium supplement in individuals with clinical indications.