Meta-analysis for effect modification by sex on the associations between fine particulate matters and cardiovascular outcomes in adults

Abstract

BACKGROUND AND AIM: Exposure to particulate matter with aerodynamic diameter no larger than 2.5 µm (PM2.5) can cause cardiovascular diseases (CVDs) but evidence for more vulnerable sex remains unclear in aiding clinical recommendations or public health approaches. We systematically reviewed observational studies and conduct meta-analysis to assess whether certain sex/gender is more vulnerable. METHODS: English-written studies published between 1995 and 2020 were searched from 4 databases. Population-based observation studies conducting sex subgroup analysis for the impacts of short-term or long-term ambient PM2.5 exposure on target CVDs were included. Random-effects meta-regression analyses were used to pool risk ratios (RRs) for long-term exposure and percent changes in outcomes for short-term exposure for a 10 µg/m³ increase in PM2.5 concentration. Quality of evidence of risk differences by sex was rated following the Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS:Data were synthesized for 5 outcomes. The difference in RRs of all CVD mortality for a 10 µg/m³ in long-term PM2.5 concentration between men and women was not significant (1.02; 95% CI, 0.97 to 1.08). The difference in percent changes in daily mortality associated with a 10 µg/m³ increase in short-term PM2.5 concentration between men and women was not significant (-0.09; 95% CI, -0.38 to 0.19). The differences in percent changes in hospitalization/ER visits between men and women were not significant for ischemic heart disease (0.07; 95% CI, -0.83 to 0.98) and cardiac arrest (1.85; 95% CI, -1.48 to 5.30). The GRADE assessment found that there was low quality of evidence for gender difference for the risks of CVD outcomes from PM2.5 exposure. A major limitation of the studies was the lack of measuring disparities in exposure between sex groups. CONCLUSIONS:This review of observational studies indicates there is currently very limited evidence of effect modification by sex/gender for the effects of PM2.5 on CVD outcomes in adults. KEYWORDS: Environmental disparities, Particulate matter, Long-term exposure, Short-term exposure, Cardiovascular diseases