The Mediating Role of Oxidative Stress on the Association Between Oxidative Balance Score and Cancer-Related Cognitive Impairment in Lung Cancer Patients: A Cross-Sectional Study.

Objectives: To explore the association between the oxidative balance score (OBS) and cancer-related cognitive impairment (CRCI) in patients with lung cancer, as well as the oxidative stress biomarkers involved.

Methods: In this cross-sectional study, 315 lung cancer patients were recruited, from whom 142 blood samples were collected to determine oxidative stress biomarkers. Dietary intake was assessed using 3-day, 24 h dietary recalls. The OBS was calculated by summing up pro- and antioxidant factors from a diet and lifestyles assessment. CRCI was evaluated using the Montreal Cognitive Assessment (MoCA) test.

Results: A total of 103 patients (32.7%) developed CRCI, with significantly lower OBS and dietary OBS and lower superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities than non-CRCI patients ( < 0.05). For every 1-point increase in OBS, the risk of CRCI was reduced by 10.6% (OR = 0.894; 95% CI 0.819, 0.977; = 0.013). Both vitamin E (OR = 0.922; 95% CI 0.868, 0.980; = 0.009) and dietary fiber (OR = 0.909; 95% CI 0.832, 0.992; = 0.032) were significantly inversely related to CRCI. The association between the total OBS and CRCI was mediated by SOD (ACME = -0.0061; 95% CI -0.0170, -0.0004; = 0.015) and GPx (ACME = -0.0069; 95% CI -0.0203, -0.0002; = 0.032), respectively.

Conclusions: Lung cancer patients with a greater balance of antioxidant to pro-oxidant diet, especially rich in dietary fiber and vitamin E, may decrease their CRCI in part by affecting SOD and GPx activities.