Impact of neighbourhood and environmental factors on the risk of incident cardiovascular disease: a systematic review and meta-analysis.

Summary

Across 28 studies (>41 million individuals), higher PM2.5 and NO2 levels, road traffic noise, and neighborhood deprivation were each associated with modest but significant increases in incident CVD risk. Evidence gaps include limited studies from the Global South and sparse data on green/blue space and retail/health service environments.

Key Findings

• PM2.5 increased incident CVD risk by 16% per 10 µg/m³ (HR 1.16, 95% CI 1.09-1.24).
• NO2 increased incident CVD risk by 5% per 10 ppb (HR 1.05, 95% CI 1.02-1.07).
• Road traffic noise increased incident CVD risk by 3% per 10 dB (RR 1.03, 95% CI 1.02-1.05).
• High neighborhood deprivation was associated with 24% higher incident CVD risk (RR 1.24, 95% CI 1.17-1.31).

Clinical Implications

Clinicians should consider environmental exposures in CVD risk assessment and advocate for policies reducing PM2.5/NO2 and traffic noise and mitigating deprivation, especially for high-risk communities.

Limitations

• Observational nature with potential residual confounding and exposure misclassification.
• Geographic bias with underrepresentation of studies from the Global South; limited data on green/blue spaces.

Future Directions

Prospective studies in low- and middle-income countries and interventional evaluations (e.g., pollution control, noise abatement, urban greening) are needed to test causality and quantify benefits.