Exposure to transportation noise and risk for cardiovascular disease in a nationwide cohort study from Denmark

Background: Transportation noise increases the risk of ischemic heart disease (IHD), but few studies have investigated subtypes of IHD, such as myocardial infarction (MI), angina pectoris, or heart failure. We aimed to study whether exposure to road, railway and aircraft noise increased risk for ischemic heart disease (IHD), IHD subtypes, and heart failure in the entire adult Danish population, investigating exposures at both maximum exposed and silent facades of each residence. Methods: We modelled road, railway, and aircraft noise at the most and least exposed facades for the period 1995-2017 for all addresses in Denmark and calculated 10-year time-weighted running means for 2.5 million individuals age >= 50 years, of whom 122,523 developed IHD and 79,358 developed heart failure during followup (2005-2017). Data were analyzed using Cox proportional hazards models, adjusted for individual and area level sociodemographic covariates and air pollution. Results: We found road traffic noise at the most exposed facade (L-den) to be associated with higher risk of IHD, myocardial infarction (MI), angina pectoris, and heart failure, with hazard ratios (HRs) (95% confidence intervals (CI)) of 1.052 (1.044-1.059), 1.041 (1.032-1.051), 1.095 (1.071-1.119), and 1.039 (1.033-1.045) per 10 dB higher 10-year mean exposure, respectively. These associations followed a near-linear exposure-response relationship and were robust to adjustment for air pollution with PM2.5. Railway noise at the least exposed facade was associated with heart failure (HR 1.28; 95% CI: 1.004-1.053), but not the other outcomes. Exposure to aircraft noise (> 45 dB) seemed associated with increased risk for MI and heart failure. Conclusions: We found road traffic noise and potentially railway and aircraft noise to increase risk of various major cardiovascular outcomes, highlighting the importance of preventive actions towards transportation noise.