Daijiworld Media Network – Madrid
Madrid, Jul 2: Exposure to air pollution may significantly increase the risk of hospitalisation and death among patients undergoing haemodialysis, according to a retrospective study conducted on individuals with end-stage kidney disease.
The study analysed 336 patients who received haemodialysis at a hospital in Madrid, Spain, between 2016 and 2024. During the study period, researchers recorded 563 hospital admissions and 90 deaths while examining the impact of air pollution and weather conditions on patient outcomes.
Researchers assessed both short-term spikes and long-term exposure to environmental factors using weekly and monthly averages. They employed multiple statistical models, including Cox proportional hazards and parametric survival models for mortality, as well as recurrent-event models for hospital admissions.

Among the pollutants studied, sulphur dioxide emerged as the strongest and most consistent predictor of adverse outcomes. The study found that exposure to sulphur dioxide was associated with an increased risk of both hospital admission and mortality, suggesting that the pollutant may have both immediate and long-term effects on patients receiving haemodialysis.
Nitrogen dioxide was also linked to a higher risk of death, although the association was observed only with prolonged exposure, indicating that its impact may accumulate over time rather than result from short-term fluctuations.
The researchers also found that certain weather conditions influenced clinical outcomes. Higher levels of solar radiation were associated with increased mortality in non-linear survival models, while higher atmospheric pressure appeared to reduce the risk of hospital admissions.
The findings suggest that environmental factors, including air pollution and weather conditions, play an important role in the health of patients with end-stage kidney disease undergoing haemodialysis.
The authors said incorporating environmental indicators into clinical risk assessment and public health strategies could help identify periods of elevated risk and enable more targeted care for dialysis patients, particularly in regions with high levels of air pollution.
The study adds to growing evidence that environmental exposures can significantly affect outcomes in people with advanced kidney disease and highlights the need to consider these factors in patient care planning.