Low serum vitamin D concentration is correlated with anemia, microinflammation, and oxidative stress in patients with peritoneal dialysis.

BACKGROUND Peritoneal dialysis (PD) is a form of dialysis to replace the function of kidney, that uses the peritoneum as a dialysis membrane to remove metabolites and water retained in the body. Vitamin D deficiency is prevalent in patients treated with PD. This research investigated the correlation between serum 25-hydroxyvitamin D [25(OH)D] concentration and anemia, microinflammation, and oxidative stress in PD patients. METHODS 62 PD patients and 56 healthy volunteers were recruited in this research. Serum concentrations of 25(OH)D and basic parameters of anemia were detected. The correlation between serum 25(OH)D concentration with anemia, oxidative stress, and microinflammatory state were analyzed. RESULTS In the PD group, the concentration of 25(OH)D was lower than the healthy control (HC) group (p < 0.001). Hemoglobin, red blood cell count (RBC), and total iron binding capacity (TIBC) in the PD group was significantly lower (all p < 0.001), while high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α) concentrations were significantly higher, than the HC group (all p < 0.001). In the PD group, malondialdehyde (MDA) concentration was higher than in the HC group (p < 0.001), while superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were lower (both p < 0.001). Serum 25(OH)D exhibited positive correlation with hemoglobin (r = 0.4509, p = 0.0002), RBC (r = 0.3712, p = 0.0030), TIBC (r = 0.4700, p = 0.0001), SOD (r = 0.4992, p < 0.0001) and GSH-Px (r = 0.4312, p = 0.0005), and negative correlation with hs-CRP (r = - 0.4040, p = 0.0011), TNF-α (r = - 0.4721, p = 0.0001), IL-6 (r = - 0.5378, p < 0.0001) and MDA (r = - 0.3056, p = 0.0157). CONCLUSION In conclusion, reduced serum 25(OH)D concentrations in PD patients contribute to anemia, oxidative stress and microinflammatory state.