TOPLINE:
Long-term exposure to fine particulate matter is associated with higher fasting blood glucose (FBG) levels and an increased type 2 diabetes risk, significantly contributing to the diabetes-related health burden among women of reproductive age.
METHODOLOGY:
- Exposure to fine particulate matter < 2.5 µm (PM2.5) is a known risk factor for type 2 diabetes, but its effect on women of reproductive age, who undergo hormonal fluctuations during reproductive events, is not well studied.
- Researchers evaluated the association of long-term exposure to PM2.5 with FBG levels and diabetes risk in 20,076,032 eligible women of reproductive age (average age, 27.04 years) across 350 cities in China between 2010 and 2015.
- They assessed PM2.5 exposure at the participants’ residential addresses and calculated average long-term exposure at 1 (lag 1 year), 2 (lag 2 years), and 3 years (lag 3 years) before the survey date, as defined by the World Health Organization (WHO).
- The primary outcomes were FBG levels and diabetes prevalence (FBG, ≥ 7 mmol/L, classified as diabetes; FBG, 6.1-7 mmol/L, classified as prediabetes).
- The study also evaluated the diabetes burden attributed to long-term PM2.5 exposure as per the Chinese National Ambient Air Quality Standards (annual mean PM2.5 exposure limit, > 35 µg/m3) and the WHO air quality guideline (annual mean PM2.5 exposure limit, > 5 µg/m3).
TAKEAWAY:
- The median PM2.5 exposure levels over lag periods of 1, 2, and 3 years were 67, 67, and 66 µg/m3, respectively, exceeding the WHO limit by more than 13-fold.
- Each interquartile range increase in the 3-year average PM2.5 exposure by 27 μg/m3 raised FBG levels by 0.078 mmol/L (P < .05), risk for diabetes by 18% (odds ratio [OR], 1.18; 95% CI, 1.16-1.19), and risk for prediabetes by 5% (OR, 1.05; 95% CI, 1.04-1.05).
- Long-term exposure to PM2.5 > 5 µg/m3 and 35 µg/m3 in the previous 3 years corresponded to an additional 41.7 (95% CI, 39.3-44.0) and 78.6 (95% CI, 74.5-82.6) thousand cases of diabetes nationwide, respectively.
- A higher PM2.5 exposure increased FBG levels and risk for diabetes in women with overweight or obesity vs those without and in those aged ≥ 35 years vs < 35 years (P < .001).
IN PRACTICE:
“These findings carry significant public health implications for formulating effective intervention strategies and environmental policies to better protect women’s health, particularly in countries with relatively high levels of air pollution and a large population with diabetes, such as China,” the authors wrote.
SOURCE:
The study, led by Yang Shen, Key Laboratory of Public Health Safety of the Ministry of Education and National Health Commission Key Laboratory of Health Technology Assessment, School of Public Health, Fudan University, Shanghai, China, was published online in Diabetes Care.
LIMITATIONS:
An error in the measurement of particulate matter exposure may have been possible as residential address estimates were used as a proxy for actual personal exposure. Questionnaires were used to retrospectively collect information on parameters such as smoking and alcohol consumption, which may have introduced recall bias. Data on potential confounders, such as diet and physical activity, were not included. Distinction between type 1 and type 2 diabetes was not reported owing to data collection–related limitations.
DISCLOSURES:
The study was supported by the National Key Research and Development Program of China, Henan Key Research and Development Program, State Key Laboratory of Resources and Environmental Information System, and Three-Year Public Health Action Plan of Shanghai. The authors declared no conflicts of interest.
A version of this article first appeared on Medscape.com.