Longitudinal evidence on the relationship between air pollutants, sarcopenia, and cognitive function in middle-aged and older adults: findings from the CHARLS cohort.

BACKGROUND

The impact of air pollutants on cognitive aging remains uncertain. This study investigates whether sarcopenia mediates the association of ozone (O3), nitrogen dioxide (NO2), and particulate matter (PM10) with cognitive decline.

METHODS

Using data from adults (≥45 years) in the 2015 and 2018 China Health and Retirement Longitudinal Study (CHARLS) waves, we employed linear regression, mediation, and restricted cubic spline analyses to assess the associations of air pollutants and sarcopenia with cognitive function (measured by mental status and episodic memory), controlling for confounders.

RESULTS

O3, NO2, PM10, and sarcopenia demonstrated significant negative associations with cognitive function (all β < 0, all 95% CI excluded 0, all P < 0.05). Sarcopenia mediated 12.79% and 6.65% of the effect of PM10 and O3, respectively. Subgroup analyses identified sex and marital status as significant effect modifiers.

CONCLUSIONS

O3, NO2, PM10, and sarcopenia were negatively associated with cognitive function. Sarcopenia partially mediated the effects of O3 and PM10.