Association between long-term exposure to particulate matter 2.5 and the risk of rapid renal function decline: a prospective study from CHARLS

This study investigated the association between PM2.5 exposure and rapid renal function decline in Chinese adults aged ≥ 45. We used data from the China Health and Retirement Longitudinal Study data from 2011–2015 (four-year follow-up period). The study outcome was rapid estimated glomerular filtration rate (eGFR) decline, defined as a decrease of ≥ 33% in eGFR from baseline. The associations between PM2.5 and rapid renal function decline were analyzed by logistic regression models and logistic generalized additive models. Among 4,365 participants, higher PM2.5 exposure was linked to increased incidence of rapid eGFR decline (P = 0.037 for trend). Higher PM2.5 concentrations, older age, a higher baseline eGFR, and elevated HbA1c and SBP levels were identified as independent risk factors for rapid renal function decline (P < 0.05). Logistic regression demonstrated that higher long-term PM2.5 exposure was associated with rapid eGFR decline (per 10-unit increase; OR = 1.158 [95% CI 1.025–1.308], P = 0.018), particularly in participants with eGFR < 90 mL/min/1.73 m2 (per 10-unit increase; OR = 1.298 [95% CI 1.066–1.582], P = 0.010). Moreover, effect modification indicated that the association between PM2.5 and rapid eGFR decline was significantly stronger in participants with hypertension than in those without hypertension (P = 0.009 for interaction). An estimated 18.8% of rapid eGFR decline cases were attributable to PM2.5. Furthermore, logistic generalized additive model analysis demonstrated non-linear associations between PM2.5 and rapid eGFR decline, with significant associations observed at higher PM2.5 concentrations (P < 0.05), especially in individuals with hypertension. Long-term exposure to high PM2.5 is associated with an increased risk of rapid renal function decline, particularly in individuals with low baseline eGFR and hypertension. This finding highlights the need for public health policies to reduce PM2.5 levels and protect vulnerable populations.