Cardiovascular benefit of statin use against air pollutant exposure in older adults.

Aims: Little is known about the cardiovascular benefit of statin use against ambient air pollution among older adults who are at higher risk of cardiovascular disease (CVD) potentially owing to age-related declines in cardiovascular functions along with other risk factors.

Methods and results: This retrospective, population-based cohort study consisted of adults aged 60 years and older free of CVD at baseline identified from the National Health Insurance Service database linked to the National Ambient Air Monitoring Information System for average daily exposure to PM10 and PM2.5 in 2015 in the major metropolitan areas in the Republic of Korea. The follow-up period began on 1 January 2016 and lasted until 31 December 2021. The Cox proportional hazards model was used to evaluate the association of cardiovascular benefit with statin use against different levels of air pollutant exposure. Of 1 229 444 participants aged 60 years and older (mean age, 67.4; 37.7% male), 377 076 (30.7%) were identified as statin users. During 11 963 322 person-years (PYs) of follow-up, a total of 86 018 incident stroke events occurred (719.0 events per 100 000 PYs). Compared to statin non-users exposed to high levels of PM10 (>50 µg/m3) and PM2.5 (>25 µg/m3), statin users had 20% [adjusted hazard ratio (HR), 0.80; 95% confidence intervals (CI), 0.75-0.85] and 17% (adjusted HR, 0.80; 95% CI, 0.80-0.86) lower adjusted risk of incident stroke for PM10 and PM2.5, respectively. A similar risk reduction for incident CVD was also found among statin users exposed to low or moderate levels of PM10 (≤50 µg/m3) and PM2.5 (≤25 µg/m3) exposure.

Conclusion: Among adults aged 60 years and older with high and low or moderate levels of exposure to PM10 and PM2.5, statin use was associated with a significantly lower risk of stroke.