Associations between short-term exposure of ambient particulate matter and hemodialysis patients death: A nationwide, longitudinal case-control study in China

Multiple air pollutant exposure is associated with higher risk of all-cause mortality in dialysis patients: a French registry-based nationwide study

Background

Little is known about the effect of combined exposure to different air pollutants on mortality in dialysis patients. This study aimed to investigate the association of multiple exposures to air pollutants with all-cause and cause-specific death in dialysis patients.

Materials and methods

This registry-based nationwide cohort study included 90,373 adult kidney failure patients initiating maintenance dialysis between 2012 and 2020 identified from the French REIN registry. Estimated mean annual municipality levels of PM2.5, PM10, and NO2 between 2009 and 2020 were combined in different composite air pollution scores to estimate each participant's exposure at the residential place one to 3 years before dialysis initiation. Adjusted cause-specific Cox proportional hazard models were used to estimate hazard ratios (HRs) per interquartile range (IQR) greater air pollution score. Effect measure modification was assessed for age, sex, dialysis care model, and baseline comorbidities.

Results

Higher levels of the main air pollution score were associated with a greater rate of all-cause deaths (HR, 1.082 [95% confidence interval (CI), 1.057-1.104] per IQR increase), regardless of the exposure lag. This association was also confirmed in cause-specific analyses, most markedly for infectious mortality (HR, 1.686 [95% CI, 1.470-1.933]). Sensitivity analyses with alternative composite air pollution scores showed consistent findings. Subgroup analyses revealed a significantly stronger association among women and fewer comorbid patients.

Discussion

Long-term multiple air pollutant exposure is associated with all-cause and cause-specific mortality among patients receiving maintenance dialysis, suggesting that air pollution may be a significant contributor to the increasing trend of CKD-attributable mortality worldwide.

Clearing the air: a review of the effects of air pollution on dialysis outcomes

PURPOSE OF REVIEW

An evolving body of literature indicates exposure to air pollutants is associated with adverse health outcomes in dialysis patients. As the prevalence of kidney disease increases, understanding the role of environmental agents on the health of dialysis patients is critical to reducing global morbidity and mortality.

RECENT FINDINGS

We identified 16 publications that investigated associations between pollutants including particulate matter (PM 2.5 and PM 10 ), carbon monoxide (CO), nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), and ozone (O 3 ) and health outcomes among dialysis patients. Eight studies examined the effects of particulate matter (PM) and four studies examined the effects CO exposure on dialysis patients. Exposure to PM was consistently associated with outcomes including all-cause mortality and a smaller body of literature suggested relationships with subclinical outcomes. Exposure to CO was associated with all-cause mortality, generalized inflammation, and uremic pruritus. An additional four studies examined multiple pollutant exposures including NO 2 , SO 2 , and O 3 and reported associations with all-cause mortality in dialysis patients.

SUMMARY

This review emphasized the nascent literature that demonstrates consistent relationships between air pollutant exposure and adverse outcomes among dialysis patients. Further research is needed to assess the impact of air pollutants, including how co-exposures will impact dialysis patient health.

The impact of long-term exposure to ambient air pollution in patients undergoing peritoneal dialysis: A cohort study in China

There is increasing evidence for an association of air pollutants and the incidence of chronic kidney disease, and the progression to end stage kidney disease (ESKD). Despite the global expansion of peritoneal dialysis (PD), the impact of environmental and climatic factors in PD patients has not been studied in detail. We aimed to assess the association of long-term residential exposure to air pollutants, with patient survival and incidence of hospitalizations. This was a cohort study of all prevalent ESKD patients who were stable on PD therapy for more than 90 days in our PD center from 2013/01/01 to 2018/12/31. The enrolled patients were followed until death, cessation of PD, loss to follow-up, or 2018/12/31. Time-varying pollutant exposures were modeled as the key time-dependent variables. We used time-dependent Cox model to evaluate the risk of mortality and hospitalizations associated with air pollutant exposures adjusted for potential confounders. A total of 886 subjects who meets inclusion criteria with 27,024 patient-months were modeled. Over a mean follow-up of 30.5 ± 21.3 months, we ascertained 246 cases of death and 2611 cases of hospital admission. Significant hazard ratios (HRs) were observed for all four air pollutants including PM_2.5 (hazard ratio [HR] 1.27, 95% confidence interval [95%CI] 1.05-1.54), PM₁₀ (HR 1.31, 95%CI 1.04-1.65), NO₂ (HR 1.45, 95%CI 1.02-2.06), and SO₂ (HR 1.20, 95%CI 1.10-1.32) in fully adjusted model, corresponding to per interquartile range μg/m³ increase of air pollutant concentrations for mortality, and non-significant HRs for incidence of hospitalization. Non-linear associations with respect to different air pollutants were observed in models for all-cause mortality and recurrent hospitalization. The estimates for mortality were significantly higher in certain groups of patients. Our findings suggest long-term exposure to ambient air pollution was associated with higher risk of all-cause mortality in PD patients, but the association with incidence of hospitalizations was less clear.

Surface ozone pollution in China: Trends, exposure risks, and drivers

Introduction

Within the context of the yearly improvement of particulate matter (PM) pollution in Chinese cities, Surface ozone (O₃) concentrations are increasing instead of decreasing and are becoming the second most important air pollutant after PM. Long-term exposure to high concentrations of O₃ can have adverse effects on human health. In-depth investigation of the spatiotemporal patterns, exposure risks, and drivers of O₃ is relevant for assessing the future health burden of O₃ pollution and implementing air pollution control policies in China.

Methods

Based on high-resolution O₃ concentration reanalysis data, we investigated the spatial and temporal patterns, population exposure risks, and dominant drivers of O₃ pollution in China from 2013 to 2018 utilizing trend analysis methods, spatial clustering models, exposure-response functions, and multi-scale geographically weighted regression models (MGWR).

Results

The results show that the annual average O₃ concentration in China increased significantly at a rate of 1.84 μg/m³/year from 2013 to 2018 (160 μg/m³) in China increased from 1.2% in 2013 to 28.9% in 2018, and over 20,000 people suffered premature death from respiratory diseases attributed to O₃ exposure each year. Thus, the sustained increase in O₃ concentrations in China is an important factor contributing to the increasing threat to human health. Furthermore, the results of spatial regression models indicate that population, the share of secondary industry in GDP, NOx emissions, temperature, average wind speed, and relative humidity are important determinants of O₃ concentration variation and significant spatial differences are observed.

Discussion

The spatial differences of drivers result in the spatial heterogeneity of O₃ concentration and exposure risks in China. Therefore, the O₃ control policies adapted to various regions should be formulated in the future O₃ regulation process in China.