Independent and interactive associations of green space and air pollution with blood lipid biomarkers: A longitudinal study

BACKGROUND: Evidence on the independent and interactive associations of green space and air pollution with novel blood lipid biomarkers remains limited. This longitudinal cohort study aimed to examine the independent and interactive associations of green space and air pollution exposure with blood lipid biomarkers. METHODS: The study included 17,242 adults undergoing health examinations in Shijiazhuang, China (2021-2023). Linear mixed-effects models estimated associations of green space and air pollution exposure with blood lipid biomarkers, including the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and the atherogenic index of plasma (AIP). Interaction terms, restricted cubic splines, and mediation analyses evaluated interaction effects, nonlinear exposure-response relationships, and mediation effects. RESULTS: < 0.05). Air pollution mixture indices statistically mediated part of the associations between green space exposure and NHHR (13.5%) and AIP (34%). CONCLUSION: Green space exposure was associated with more favorable lipid biomarkers, whereas air pollution showed adverse associations. Green space is associated with weaker air pollution-related dyslipidemia.