Joint Damage and Low Lean Body Mass in a Cohort of Peruvian Patients With Rheumatoid Arthritis

Objectives To determine the association between radiologic joint damage (JD) and a lower lean body mass (LBM) in rheumatoid arthritis (RA) patients. Methods A cross-sectional study from a single center established RA cohort. JD and appendicular LBM (arms and legs) were measured with the Sharp/van der Heijde (SvdH) score and dual x-ray absorptiometry expressed as kg/m², respectively. A univariable analysis was used to determine the association between JD an LBM; then, a multivariable regression model was performed to evaluate the persistence of this association, adjusted by age, gender, disease duration, socioeconomic status (by the Graffar method), tobacco use, anticitrullinated protein antibody levels, Disease Activity Score in 28 joints for RA with erythrocyte sedimentation rate, glucocorticoid use (as prednisone equivalent), disease-modifying antirheumatic drug use, body mass index, and disability (by the multidimensional Health Assessment Questionnaire). Results Two hundred forty-seven patients were included; the average (SD) age was 63.0 (12.8) years, disease duration 20 (15.00) years, the total SvdH was 66 (86.75), and the aLBM was 13.6 (3.82) kg/m². In the univariable analysis, a lower appendicular LBM was associated with higher SvdH score on the female population, in terms of the total (B = -8.6, p < 0.01), bone erosion (-4.4, p < 0.01), and joint space narrowing (-4.2, p < 0.01) scores; this correlation remained in the multivariable analysis in terms of total SvdH (B = -9.5, p < 0.01), bone erosion (-5.2, p < 0.01), and joint space narrowing (-4.3, p < 0.01). Conclusions A lower LBM in female patients was associated with more severe JD independently of other variables examined. Strategies aimed at preserving LBM could have a favorable impact on the course of disease.