The Associations Between Secondhand Smoke Exposure and Various Cardiovascular Diseases: A Meta-Analysis

Area of Science:

• Environmental Health
• Cardiovascular Medicine
• Public Health Policy

Background:

• Existing meta-analyses on secondhand smoke (SHS) and cardiovascular disease (CVD) present knowledge gaps and inconsistent findings.
• This study addresses the need for a comprehensive examination of SHS associations with specific CVDs, considering moderating factors.

Purpose of the Study:

• To meta-analyze the association between SHS exposure and various individual cardiovascular diseases.
• To investigate potential moderation effects of sex, country/region, and exposure type on the SHS-CVD relationship.

Main Methods:

• Systematic literature search across four major databases (PubMed, CINAHL ultimate, Embase, Web of Science) up to May 2, 2024.
• Meta-analysis using robust variance estimation, with bias assessment via Cochrane ROBINS-E.
• Subgroup analyses conducted for sex, geographic regions, and exposure types; heterogeneity and publication bias were assessed.

Main Results:

• SHS exposure is associated with increased odds of hypertension (OR: 1.28), heart disease (OR: 1.39), myocardial infarction (OR: 1.50), stroke (OR: 1.36), and nonspecific CVDs (OR: 1.50).
• Geographic variations observed: U.S. showed lower odds ratios compared to European countries for various CVDs.
• Home-based SHS exposure demonstrated a higher risk for CVD compared to non-home exposure; no significant sex differences were identified.

Conclusions:

• Elevated risks of multiple CVDs are linked to SHS exposure.
• Public education, government-level smoking bans, and promotion of smoke-free homes are crucial public health recommendations.