Long-term exposure to ambient fine particulate matter and mortality from renal failure: a retrospective cohort study in Hong Kong

Abstract

Numerous studies have indicated the ambient particulate matter is closely associated with increased cardiovascular disease, yet the evidence for its association with the renal disease remains under-recognized. We aimed to estimate the association between long-term exposure to fine particulate matter (PM2.5) and renal failure (RF) mortality among participants of the Elderly Health Service Cohort in Hong Kong from 1998 to 2010. PM2.5 concentration at the residential address of each participant was estimated based on a satellite-based spatiotemporal model. We used Cox proportional hazards regression to estimate the risks of overall renal failure (RF) and cause-specific mortality associated with PM2.5. After excluding 5,373 subjects without information on the residential address or relevant covariates, a total of 61,447 participants were included in data analyses. We totally identified 443 RF deaths during the 10 years of follow-up. For an interquartile-range increase in PM2.5 concentrations (3.22 μg/m3), hazard ratios of RF mortality were 1.23 (95% confidence interval (CI): 1.06 to 1.43) among all cohort participants and 1.42 (95% CI: 1.16 to 1.74) among patients with chronic kidney disease. Long-term exposure to atmospheric PM2.5 might be an important risk factor of RF mortality in the elderly population, especially among participants with existing renal diseases.