The Impact of Renal Replacement Therapy on FeNO Levels and Pulmonary Function in End‐Stage Renal Disease Patients

Background Renal replacement therapy (RRT) is crucial for end‐stage renal disease, yet its pulmonary effects remain unclear. Fractional exhaled nitric oxide (FeNO) serves as a biomarker for airway inflammation. This study evaluates FeNO levels in hemodialysis (HD) and peritoneal dialysis (PD) patients and their relationship with pulmonary function. Methods RRT patients aged 18–65, followed for at least 2 years in our nephrology clinic, were included. FeNO tests were performed after routine blood sampling. The study comprised 110 patients: 50 HD, 30 PD, and 30 controls. Results FeNO levels before and after dialysis were statistically significantly higher in HD patients compared to PD patients ( p = < 0.001 for both). Exhaled NO levels measured in the control group were 7.6 ± 5.2 ppb and were statistically significantly lower compared to HD patients before and after dialysis ( p = < 0.001 for both). A negative correlation was observed between FeNO and FEV1 and FVC percent ( R = −0.807, p = 0.01; R = −0.801, p = 0.01, respectively). A positive correlation was observed between exhaled NO levels before and after dialysis and ΔFVC, ΔFEV1, and ΔPEF25–75 ( R = 0.74, p = 0.01; R = 0.74, p = 0.01; R = 0.89, p = 0.01, respectively). Conclusion This study showed that FeNO levels were significantly higher in HD patients before and after RRT compared to PD and healthy controls, suggesting a greater impact of HD on airway inflammation. FeNO measurement may serve as a biomarker for monitoring pulmonary health in RRT patients.