Ozone serve as mediator and effect modifier in the temperature-eGFR association: A longitudinal study on health...

The precise role of ozone (O₃) in modulating temperature's impact on kidney function remains unclear. This study systematically investigates O₃'s modification and mediation effects on the association between temperature and glomerular filtration rate (eGFR). We collected 26,244 individuals from the First Affiliated Hospital of Jinan University. A Generalized Linear Mixed Model was used to analyze the mediation and interaction effects of O₃ on the temperature-eGFR association, and a Quantile-Based g-Computation model estimated their joint effect. We found that eGFR decreased by 0.29 mL/min/1.73 m² (95 % CI: -0.32, -0.26) per 1 °C increases in temperature and 0.36 mL/min/1.73 m² (95 % CI: -0.39, -0.32) per 10 μg/m³ O₃ increase. An IQR increase in temperature and O₃ led to a 3.25 mL/min/1.73 m² eGFR decline (95 % CI: -3.27, -3.23), with temperature and O₃ contributing 67.53 % and 32.47 %, respectively. A significant synergistic effect of O₃ and temperature was observed, with high temperature-high O₃ (HT-HO) events being associated with the greatest relative risk (RR = 2.71, 95 % CI: 2.36-3.13) of low eGFR, compared to low temperature-low O₃ (LT-LO) events. Approximately 20.56 % of the total effect was partly explained by O₃. Individuals with rapid renal function decline were more vulnerable. Both temperature and O₃ were associated with reduced renal function, with O₃ acting as mediator and modifier.