[Association between low handgrip strength and air pollution among people aged 50 years and over]

Objective: To examine the association between long-term exposure to ambient PM(2.5) combined with indoor air pollution and handgrip strength among people aged 50 and over. Methods: Data were from the first wave of World Health Organization Study on global AGEing and adult health in China. Ambient annual concentration of PM(2.5) was estimated by using the satellite data we also investigated the use of fuels and chimneys as indoor air pollution. A two-level (individual level and community level) linear model was applied to examine the association between long-term exposure to ambient PM(2.5) combined with indoor air pollution and the handgrip strength. Results: A total of 13 175 individuals aged 50 years and over were included for analysis. The handgrip strength was (26.67±0.54) kg. Ambient PM(2.5) was found to be significantly associated with the risk of decreased handgrip strength. Outdoor PM(2.5) concentration was negatively correlated with handgrip strength (β=-0.23, 95%CI: -0.31 - -0.14) decrease in handgrip strength after adjusting for gender, age, residence, education, household assets, intake of vegetables and fruits, smoking and drinking, physical activity. In rural area, compared to those who used solid fuel, use of clean fuel increased (β=1.41, 95%CI: 0.36-2.46) handgrip strength. But in urban area, we did not find any statistically significant association between the use of clean fuel and handgrip strength (β=0.19, 95%CI: -0.95-1.32). Conclusion: This study found that long-term exposure to ambient PM(2.5) combined with indoor air pollution was significantly associated with low handgrip strength among people aged 50 years and over, this suggested that ambient PM(2.5) might serve as one of the risk factors for low physical function seen in the people aged 50 years and over.