Choi, Jiwon

Background Antibiotic use may alter gut microbiota, which could be associated with various diseases, including cardiovascular disease (CVD). Accordingly, further epidemiological evidence is needed to clarify the potential risk of CVD associated with antibiotic exposure. We evaluated the association between long‐term antibiotic exposure and CVD risk in South Korea. Methods and Results This nationwide retrospective cohort study used data from the Korean National Health Insurance Service database. A total of 2 159 965 individuals aged 40 to 79 years who had no history of antibiotic prescriptions from 2004 to 2005 were included and followed through December 31, 2021. Antibiotic exposure was defined as the cumulative days of antibiotic prescriptions from 2006 to 2010. The primary end point was incident CVD with 2 or more days of hospitalization from 2011 to 2021. Adjusted hazard ratios (aHR) and 95% CIs for CVD according to antibiotic exposure were estimated using multivariable Cox proportional hazards models, adjusting for a range of covariates. Longer cumulative antibiotic prescription days were associated with an increased risk of CVD. The aHRs for CVD associated with 1 to 14, 15 to 90, 91 to 180, 181 to 364, and ≥365 days of antibiotic exposure were 0.98 (95% CI, 0.96–1.01), 1.01 (95% CI, 0.99–1.03), 1.05 (95% CI, 1.03–1.08), 1.06 (95% CI, 1.04–1.09), and 1.10 (95% CI, 1.07–1.13) compared with those with no antibiotic prescriptions. Conclusions In this large population‐based cohort study of Korean adults, long‐term antibiotic exposure may be associated with a higher risk of CVD. Further research is warranted to establish causality and elucidate the underlying mechanisms for this association.