, Volume 56, Issue 1, pp 36-46
Date: 24 Aug 2012

Long-term exposure to traffic-related air pollution and diabetes-associated mortality: a cohort study

Abstract

Aims/hypothesis

The aim of this study was to investigate whether air pollution from traffic at a residence is associated with mortality related to type 1 or type 2 diabetes.

Methods

We followed up 52,061 participants in the Danish Diet, Cancer and Health cohort for diabetes-related mortality in the nationwide Register of Causes of Death, from baseline in 1993–1997 up to the end of 2009, and traced their residential addresses since 1971 in the Central Population Registry. We used dispersion-modelled concentration of nitrogen dioxide (NO2) since 1971 and amount of traffic at the baseline residence as indicators of traffic-related air pollution and used Cox regression models to estimate mortality-rate ratios (MRRs) with adjustment for potential confounders.

Results

Mean levels of NO2 at the residence since 1971 were significantly associated with mortality from diabetes. Exposure above 19.4 μg/m3 (upper quartile) was associated with a MRR of 2.15 (95% CI 1.21, 3.83) when compared with below 13.6 μg/m3 (lower quartile), corresponding to an MRR of 1.31 (95% CI 0.98, 1.76) per 10 μg/m3 NO2 after adjustment for potential confounders.

Conclusions/interpretation

This study suggests that traffic-related air pollution is associated with mortality from diabetes. If confirmed, reduction in population exposure to traffic-related air pollution could be an additional strategy against the global public health burden of diabetes.

K. Overvad and Z. J. Andersen contributed equally to this study.