Long-term exposure to ambient air pollution with sarcopenia among middle-aged and older adults in China

Abstract

Background: Few studies have examined the role of outdoor air pollution exposure in sarcopenia in Asia. We aimed to investigate the association of outdoor air pollutants exposure with sarcopenia among Chinese adults.

Methods: This nationally population-representative study used data from the China Health and Retirement Longitudinal Study (CHARLS) in 2015, 11,700 participants at least 45 years old from 125 Chinese cities were included. Sarcopenia status was identified according to the Asian Working Group for Sarcopenia 2019 (AWGS 2019) criteria. Ambient annual average air pollutants including fine particulate matter (PM_2.5), inhalable particles (PM₁₀), coarse particulate matter (PM_coarse), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and carbon monoxide (CO) were estimated by satellite models and ground-based measurements. Multinomial logistic regression models were performed to examine the associations of air pollutants exposure with different status of sarcopenia (including possible sarcopenia and sarcopenia). Stratified analyses were utilized to assess the effect modifiers.

Results: Among the 11,700 participants (52.6% women), the average age was 61.0 years. Each 10 μg/m³ increment of annual PM_coarse was associated with a higher risk of possible sarcopenia (odds ratio (OR) = 1.08, 95% confidence interval (CI) 1.04-1.11). Stratified analyses showed a positive risk of possible sarcopenia in women after exposure to PM₁₀, PM_coarse, and NO₂. Ambient NO₂ exposure was positively associated with sarcopenia (OR = 1.13, 95% CI 1.04-1.22) in those aged 65 years and older. However, we have not observed differences by sex, age, residence, smoking, and drinking. Robustness results were found for PM_coarse in the sensitivity analyses.

Conclusion: This nationwide study suggested that long-term exposure to outdoor air pollution, especially for PM_coarse, was associated with the risk of sarcopenia among Chinese adults. Our findings provide epidemiological implications for protecting healthy ageing by improving air quality.

Keywords: Air pollution; Exposure; Muscle mass; Nitrogen dioxide; Particulate matter; Sarcopenia.