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

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. 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. O₃, NO₂, PM₁₀, and sarcopenia demonstrated significant negative associations with cognitive function (all <i>β</i> &lt; 0, all 95% CI excluded 0, all <i>P</i> &lt; 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. O₃, NO₂, PM₁₀, and sarcopenia were negatively associated with cognitive function. Sarcopenia partially mediated the effects of O₃ and PM₁₀.