Long-term exposure to road traffic noise and stroke incidence: a Danish Nurse Cohort study

Abstract

Background Road traffic noise has been linked to increased risk of ischemic heart disease, yet evidence on stroke shows mixed results. We examine the association between long-term exposure to road traffic noise and incidence of stroke, overall and by subtype (ischemic or hemorrhagic), after adjustment for air pollution. Methods Twenty-five thousand six hundred and sixty female nurses from the Danish Nurse Cohort recruited in 1993 or 1999 were followed for stroke-related first-ever hospital contact until December 31st, 2014. Full residential address histories since 1970 were obtained and annual means of road traffic noise (Lden [dB]) and air pollutants (particulate matter with diameter < 2.5 μm and < 10 μm [PM2.5 and PM10], nitrogen dioxide [NO2], nitrogen oxides [NOx]) were determined using validated models. Time-varying Cox regression models were used to estimate hazard ratios (HR) (95% confidence intervals [CI]) for the associations of one-, three-, and 23-year running means of Lden preceding stroke (all, ischemic or hemorrhagic), adjusting for stroke risk factors and air pollutants. The World Health Organization and the Danish government’s maximum exposure recommendations of 53 and 58 dB, respectively, were explored as potential Lden thresholds. Results Of 25,660 nurses, 1237 developed their first stroke (1089 ischemic, 148 hemorrhagic) during 16 years mean follow-up. For associations between a 1-year mean of Lden and overall stroke incidence, the estimated HR (95% CI) in the fully adjusted model was 1.06 (0.98–1.14) per 10 dB, which attenuated to 1.01 (0.93–1.09) and 1.00 (0.91–1.09) in models further adjusted for PM2.5 or NO2, respectively. Associations for other exposure periods or separately for ischemic or hemorrhagic stroke were similar. There was no evidence of a threshold association between Lden and stroke. Conclusions Long-term exposure to road traffic noise was suggestively positively associated with the risk of overall stroke, although not after adjusting for air pollution.

Association between Noise and Cardiovascular Disease in a Nationwide U.S. Prospective Cohort Study of Women Followed from 1988 to 2018

“…In addition, positive associations of traffic noise, but not railway noise, with stroke were found in a pooled analysis of nine Scandinavian cohorts [ traffic-noise adjusted- 1.06 (95% CI: 1.03, 1.08), per 10-dBA increment], but several other cohort studies found no evidence for the association of traffic noise with stroke or stroke subtypes after the models were adjusted for air pollution. 26 , 54 In fully adjusted models that included adjustment for , we generally found positive associations with stroke and stroke subtypes. Finally, in contrast to other cohort studies that explored associations of stroke subtypes with noise, 21 , 26 , 53 – 55 we found suggestions of stronger associations for hemorrhagic stroke compared with ischemic stroke in anthropogenic noise models, although hemorrhagic stroke CIs were wide in our study.…”

“… 4 In agreement with other cohort studies, our study found increased risk of CHD (nonfatal MI or fatal CHD) associated with noise, but relatively smaller associations for stroke or stroke subtypes. 26 , 27 , 52 – 54 Similarly, a nationwide cohort study of the entire Danish population found positive associations of traffic noise with CHD [ traffic-noise adjusted- 1.04 (95% CI: 1.03, 1.05), per 10-dBA increment]. In addition, positive associations of traffic noise, but not railway noise, with stroke were found in a pooled analysis of nine Scandinavian cohorts [ traffic-noise adjusted- 1.06 (95% CI: 1.03, 1.08), per 10-dBA increment], but several other cohort studies found no evidence for the association of traffic noise with stroke or stroke subtypes after the models were adjusted for air pollution.…”

A cohort study evaluating the risk of stroke associated with long-term exposure to ambient fine particulate matter in Taiwan

“…Discrepant findings among studies may reflect variations in characteristics of study populations, methods of exposure assessments, and the covariates considered. For example, evidence has shown a positive association between road traffic noise and risk of stroke, independent [ 39 ] or not independent [ 40 ] of air pollution. However, most studies, including ours, did not consider the potential confounding effect of noise exposure in assessing stroke risk associated with PM 2.5 exposure.…”

Risk Associations between Vehicular Traffic Noise Exposure and Cardiovascular Diseases: A Residential Retrospective Cohort Study

“…Other authors found that road traffic noise increased the risk of stroke independently from other factors (NO x air concentration, smoking habits, diet, and alcohol consumption) [ 28 , 60 , 61 , 62 , 63 ]. Cole-Hunter et al (2021) reported a positive association between long-term exposure to road traffic noise and the risk of overall stroke, but without adjusting for air pollution (PM 2.5 and NO 2 ) [ 64 ]. Furthermore, positive, but not statistically significant, associations with mortality for cardiovascular and ischemic cardiopathy and stroke in both adults and the elderly were observed [ 40 ].…”