The Dysfunctional Chronic Pain (Dysfunctional CP) phenotype is an empirically-identifiable CP subtype with unclear pathophysiological mechanisms that cuts across specific medical CP diagnoses. This study tested whether the multidimensional pain and psychosocial features that characterize the Dysfunctional CP phenotype are associated broadly with elevated oxidative stress (OS). Measures of pain intensity, bodily extent of pain, catastrophizing cognitions, depression, anxiety, sleep disturbance, pain interference, and function were completed by 84 chronic osteoarthritis patients prior to undergoing total knee arthroplasty. Blood samples were obtained at the initiation of surgery prior to incision or tourniquet placement. Plasma levels of F2-isoprostanes (IsoPs) and isofurans (IsoFs), the most highly specific measures of in vivo OS, were quantified using gas chromatography/negative ion chemical ionization mass spectrometry. Results indicated that controlling for differences in age, sex, and body mass index, higher overall OS (mean of IsoPs and IsoFs) was associated with significantly (p’s .10). Results build on prior case-control findings suggesting that presence of a CP diagnosis is associated with elevated OS, highlighting that it may specifically be individuals displaying characteristics of the Dysfunctional CP phenotype who are characterized by elevated OS. Clinical implications of these findings remain to be determined.
Copyright © 2021 International Association for the Study of Pain.