Association of physical function and sleep with oxidative stress in adults with chronic pain: A pragmatic clinical trial secondary analysis

Objective This study aimed to evaluate the potential utility of 8-hydroxy-2ʹ-deoxyguanosine as a biomarker for pain-related functional outcomes. Methods This is a secondary analysis of a pragmatic clinical trial that recruited active duty service members with chronic pain. Participants underwent a 6-week interdisciplinary pain management program and completed measures of sleep-related function and physical function, including objective measures of treadmill, lift, and carry battery. Urine samples were collected at baseline and 6 weeks. We estimated partial correlations among changes in 8-hydroxy-2ʹ-deoxyguanosine, sleep-related function, and physical function, adjusting for baseline 8-hydroxy-2ʹ-deoxyguanosine and participant demographics. Given the exploratory nature of this study, we used a significance threshold of p < 0.10. Results Changes in 8-hydroxy-2ʹ-deoxyguanosine levels were negatively associated with changes in sleep-related function at both 3 weeks (r = −0.17; 90% confidence interval: −0.3 to −0.03) and 6 weeks (partial r = −0.24; 90% confidence interval: −0.38 to −0.1). Participants’ sleep-related function and physical function improved from baseline to 3 and 6 weeks ( P < 0.001), whereas 8-hydroxy-2ʹ-deoxyguanosine levels decreased over time. Conclusions Among active duty service members with chronic pain, changes in physical function and sleep-related function were associated with changes in oxidative stress. Trial registration: ClinicalTrials.gov identifier NCT03297905