Influence of Inflammation on Red Blood Cell Lifespan in Peritoneal Dialysis Patients

Background and hypothesis: Renal anemia is linked to a decreased lifespan of red blood cells. The factors influencing red blood cell lifespan (RBCLS) in peritoneal dialysis patients, particularly the connection between inflammation and RBCLS, are still not well understood. This cross-sectional study was conducted to investigate these relationships. Methods: Patients who had been undergoing peritoneal dialysis for more than 3 months were selected for this study. The carbon monoxide exhalation method was used to detect the life span of red blood cells. The patients were then divided into two groups based on whether the RBCLS was shorter than 75 days. General information, anemia-related indicators, and other laboratory indicators along with their treatment were compared between the two groups. The different indicators were then included in a logistic regression analysis to identify independent risk factors that influence the shortening of RBCLS. Results: A cohort of 59 peritoneal dialysis patients was examined, revealing a median RBCLS of 88 days. Of these patients, 39 exhibited a normal RBCLS, while 20 had a shortened lifespan. A comparison of the two groups indicated that patients with a shorter RBCLS exhibited lower levels of PD vintage (29.5 vs. 56.0, p = 0.031), albumin (34.62 ± 3.01 vs. 37.41 ± 3.60, p = 0.004), cholesterol (4.02 ± 0.54 vs. 4.55 ± 1.21, p = 0.026), and low-density cholesterol (2.19 ± 0.43 vs. 2.75 ± 0.87, p = 0.002), and a higher neutrophil-to-lymphocyte ratio (NLR) (3.05 vs. 2.61, p = 0.026) compared to those with a normal RBCLS. The logistic regression results indicated that PD vintage (OR 0.976, CI 0.958-0.999), albumin (OR 0.668, CI 0.514-0.867), low-density lipoprotein cholesterol (OR 0.046, CI 0.002-0.953), and NLR (OR 1.792, CI 1.016-3.162) were identified as independent risk factors influencing the shortening of RBCLS. Conclusion: Hypoalbuminemia, low LDL, and high NLR in peritoneal dialysis patients are identified as independent risk factors associated with a shortened RBCLS. Key learning points: RBCLS is reduced in both peritoneal dialysis and hemodialysis patients. The neutrophil-to-lymphocyte ratio (NLR) in peripheral blood, a simple and readily available laboratory indicator, can reflect the inflammatory status. This study adds: Nutritional status (albumin and LDL) and inflammatory status (NLR) are significant factors that impact the lifespan of red blood cells in peritoneal dialysis patients. Potential impact: This study presents novel findings on the relationship between chronic inflammation and RBCLS in patients with chronic kidney disease, highlighting the need for additional research in this area.