Association of Protein Energy Wasting and Oxidative Stress Markers in Peritoneal Dialysis

Protein-energy wasting (PEW) is highly prevalent among patients undergoing peritoneal dialysis (PD), and it has been proposed that oxidative stress (OS) may contribute to its pathogenesis. This study was an attempt to determine the association between the presence of PEW and OS levels in PD patients.

This analytical cross-sectional study involved 62 clinically stable PD patients aged ≥ 18 years, between September 2017 and July 2018. PEW was assessed using PEW definition criteria, 7-point Subjective Global Assessment (SGA), and Malnutrition-Inflammation Score (MIS). Redox state was evaluated through oxidants (lipoperoxides, 8-Isoprostane, nitric oxide), antioxidants (superoxide dismutase, catalase, glutathione peroxidase-GPx, total antioxidant capacity), and oxidative DNA damage [8-hydroxy2'-deoxyguanosine-8-OHdG, 8-Oxoguanine-DNA-N-Glycosylase-1(8-OHdG)].

Among study participants, 38 (61.2%) were males and 24 (38.8%) were females; 22 (35.4%) had diabetes mellitus [males 15 (68.1%) and females 7 (31.8%)]. The average PD duration was 11 (4-27) months, body mass index: 23.5 ± 4.1 kg/m2, energy intake: 1138.4 ± 394.2 kcal/day, and protein intake: 50.2 ± 18.5 g/day. Prevalence of PEW varied based on the assessment method used (50-88.7%). Plasma 8-OHdG levels were higher in patients with PEW evaluated by MIS (0.1 [0.1-56.4] vs. 1.8 [0.1-74.7] ng/mL, P = .028), while GPx activity was lower in the presence of PEW as measured by MIS (3.6 [3.1-7.6] vs. 2.8 [1.2-10] nmol/min/mL, P = .021). No significant differences were observed between PEW markers and remaining OS levels.

In PD patients with PEW, assessed by MIS, 8-OHdG was significantly increased, while GPx activity was significantly low.