Association between indoor air pollution exposure and dyslipidemia among Chinese adults: The role of leisure-time physical activity

Dyslipidemia, a major factor for cardiovascular diseases, has been linked to air pollution exposure. However, evidence on the association between indoor air pollution (IAP) from solid fuel use and dyslipidemia remains limited, as does the potential mitigating role of leisure-time physical activity (LTPA). This cross-sectional study analyzed data from 69,680 adults in the China Multi-Ethnic Cohort (CMEC). IAP exposure was assessed based on self-reported solid fuel use for cooking and heating. Dyslipidemia was defined using blood lipid measurements. LTPA was quantified in metabolic equivalent task-hours per week (MET-h/week). Multivariable logistic regression and interaction analyses were conducted to evaluate associations and synergistic effects. Each 10 MET-h/day increase in LTPA was associated with a 9 % reduction in the prevalence of high non-HDL-C (OR = 0.91, 95 % CI: 0.84-0.98) and a 13 % reduction in hypertriglyceridemia (OR = 0.87, 95 % CI: 0.82-0.92). Solid fuel use for cooking was significantly associated with an increased prevalence of hypertriglyceridemia (OR = 1.14, 95 % CI: 1.09-1.20) and hyperbetalipoproteinemia (OR = 1.20, 95 % CI: 1.13-1.28), while, solid fuel use for heating was linked to higher prevalence of hypertriglyceridemia (OR = 1.34, 95 % CI: 1.27-1.42) and hypoalphalipoproteinemia (OR = 1.13, 95 % CI: 1.05-1.21). LTPA attenuated these associations, with significant multiplicative and additive-scale interactions observed (e.g., for heating fuel use and LTPA on dyslipidemia: P-interaction < 0.05, RERI = 0.18, 95 % CI: 0.08-0.27). Participants using solid fuels and engaging in low LTPA had the highest prevalence of dyslipidemia. Moreover, subgroup analyses confirmed stronger adverse effects of IAP in low-LTPA individuals. Household solid fuel use is associated with dyslipidemia, particularly hypertriglyceridemia and hyperbetalipoproteinemia. LTPA may mitigate these associations, highlighting the dual importance of clean energy adoption and physical activity (PA) promotion in reducing dyslipidemia burden. Public health strategies should target high- populations, such as rural communities with limited access to clean fuels.