Long-Term Exposure to Noise and the Development of Diabetes and Hypertension in Toronto, Canada: A Cohort Study

Background: Exposure to noise has been linked to cardiovascular disease risk factors, such as elevated blood pressure and glucose dysregulation. However, epidemiologic evidence linking road traffic noise and cardiovascular disease and its risk factors remains scarce in North America. We assessed associations between road traffic noise and the incidence of diabetes and hypertension in Toronto, Canada, which is the fourth largest city in North America.Methods: We conducted a population-based cohort study of ~1 million individuals, who were aged 35-100 years and long-term residents of Toronto. Noise levels were derived using SoundPLAN Acoustics software as equivalent A-weighted sound pressure level from traffic for nighttime (LAeqNight) and 24-hour day (LAeq24h). Three-year average levels of noise were assigned to subjects’ annual residential postal codes. To estimate the association between noise and outcomes, we used random-effect Cox proportional hazards models adjusting for personal and area-level ...