Physical activity attenuated the association of air pollutants with telomere length in rural Chinese adults.

Exposure to air pollutants (nitrogen dioxide (NO 2) and particulate matters (PMs)) or physical inactivity is linked to telomere length (TL) shortening. However, there is a lack of research on combined effects of either NO 2 or PMs and physical activity (PA) on TL. This study aimed to explore the joint associations of air pollutants (NO 2 or PMs) and PA with relative TL in rural Chinese adults. This study was conducted among 2704 participants aged 18–79 years in rural China. Concentrations of NO 2 and PMs (PM with an aerodynamics diameter ≤ 1.0 μm (PM 1), ≤2.5 μm (PM 2.5) or ≤10 μm (PM 10)) were estimated using random forest models incorporated with satellites data, meteorological data, and land use information. Relative TL of each participant was measured by a quantitative real-time polymerase chain reaction. Linear regression models were applied to examine the independent associations between PA, NO 2 or PMs and relative TL. Interaction plots were used to depict the altered associations between NO 2 , PM 1 , PM 2.5 , or PM 10 and relative TL along with increasing PA levels. Each 1 μg/m3 increment in NO 2 , PM 1 , PM 2.5 , or PM 10 was associated with a 0.038 (95% confidence intervals (CI): −0.044, −0.033), 0.036 (95% CI: −0.041, −0.031), 0.052 (95% CI: −0.059, −0.045), or 0.022 (95% CI: −0.025, −0.019) decrease in relative TL among all participants; similar findings were observed among normal glucose tolerance or impaired fasting glucose (IFG) participants as well as type 2 diabetes mellitus (T2DM) patients. PA at certain levels counteracted the association of air pollutants (NO 2 , PM 1 , PM 2.5 , and PM 10) with relative TL among IFG participants or T2DM patients. Long-term exposure to NO 2 and PMs was associated with relative TL shortening and these effects may be counteracted by PA at certain levels in IFG participants or T2DM patients. Unlabelled Image • Exposure to high air pollutants was related to RTL shortening in rural adults. • Physical activity attenuated the negative associations of air pollutants with RTL. • Physical activity counteracted the effect of air pollutants on RTL in T2DM patients. [ABSTRACT FROM AUTHOR]