Systemic inflammation and painful joint burden in osteoarthritis: A Matter of Sex?

Abstract Objective We investigated the association between serum levels of C-reactive protein (CRP) and the extent of multijoint pain among individuals with hip/knee osteoarthritis (OA) and determined whether the association differs by sex. Design Serum CRP and cartilage oligomeric matrix protein (COMP) were determined by ELISA in 189 individuals (101 female, 88 male) scheduled for total hip/knee arthroplasty for OA. Patients indicated on a homunculus all painful joints; a summed count was derived. A series of negative binomial regression models was used to investigate the cross-sectional association between painful joint count (outcome) and serum CRP concentrations, adjusting for age, sex, BMI, comorbidity count and COMP. An interaction between sex and these biomarkers was tested. Results Mean age: 66 among women, 65 among men. Women had higher mean joint count (3.7 vs 2.5, p