According to researchers who conducted a study of more than 1 million long-term Toronto residents between ages 35 and 100 over a 15-year period, the risk of developing diabetes or high blood pressure increased as people were chronically exposed to elevated traffic-related noise.

For each 10-decibel increase in average traffic noise, there was an 8 percent increase in new cases of diabetes, and a 2 percent increase in new cases of high blood pressure.

The risks remained heightened even after adjusting for environmental and socioeconomic factors, and the link was stronger in women and younger people.

The study’s senior author, Hong Chen, a research scientist with Health Canada, said noise exposure can instigate multiple stress responses, increasing the level of stress hormones. Repeated exposure over time may contribute to metabolic problems and insulin resistance.

The study, published in the Journal of the American Heart Association, is part of a growing body of research about the possible negative health impacts of traffic noise.