Updated exposure-response relationship between road traffic noise and coronary heart diseases: a meta-analysis.

A meta-analysis of 14 studies (17 individual effect estimates) on the association between road traffic noise and coronary heart diseases was carried out. A significant pooled estimate of the relative risk of 1.08 (95% confidence interval: 1.04, 1.13) per increase of the weighted day-night noise level L DN of 10 dB (A) was found within the range of approximately 52-77 dB (A) (5 dB-category midpoints). The results gave no statistically significant indication of heterogeneity between the results of individual studies. However, stratified analyses showed that the treatment of gender in the studies, the lowest age of study subjects and the lowest cut-off of noise levels had an impact on the effect estimates of different studies. The result of the meta-analysis complies quantitatively with the result of a recent meta-analysis on the association between road traffic noise and hypertension. Road traffic noise is a significant risk factor for cardiovascular diseases.