Associations between ozone exposure and mortality have been established. However, the relationship between ozone exposure and diabetes mellitus mortality, 1 of the top 10 leading causes of death in the world, remains unclear. In this study, we aim to explore the relationship between ozone exposure and mortality from diabetes.
Between 2006 and 2008, death of diabetic (ICD-9, 250; N = 5767) patients more than 50 years of age taken from National Mortality Registry in metropolitan Taipei, Taiwan, were included for analysis. Average levels of ozone each day were calculated from 15 monitoring stations of Taiwan Environmental Protection Agency in this area. Case-crossover design was applied to examine the odds ratio between the risk and reference periods, whereas daily moving average from zero day (the day of death) to seventh day was used, and 4 reference days were chosen by every 7 days before the day of death for 1 month. Temperature and relative humidity were included in the 1-pollutant model, and PM10 or PM2.5 was further adjusted in 2-pollutant model separately after calculating the correlation of air pollutants.
In 2-pollutant model with PM2.5 adjusted, the trend of accumulative effect of ozone was observed. Diabetic patients were at risk (OR = 1.09, 1.01–1.17) for deaths in an interquartile increase of ozone (11.6 ppb) within 5 days exposure. In ozone-associated deaths from diabetes, male was at higher risk (OR = 1.14, 1.03–1.26), and younger age group (50–65: OR = 1.19, 1.01–1.40) was at elevated risk than older groups. Similar results were also observed when PM10 was controlled in 2-pollutant model.
Mortality from diabetes is associated with increased ozone exposure, and the risk is higher for males and those aged 50–65. The specific causes of diabetes mellitus death need further investigation.