Rheumatoid cachexia in early rheumatoid arthritis: prevalence and associated variables

Rheumatoid cachexia (RC) is prevalent among patients with established rheumatoid arthritis (RA). Although changes in muscle mass and fat mass have been reported in early RA, these findings have not been classified according to existing RC definitions. This study aimed to describe the prevalence of RC and associated variables in patients with early RA.

This cross-sectional study included 87 patients. Body composition was evaluated with dual-energy X-ray absorptiometry after a median disease duration of 15 months. RC was defined as a fat-free mass index < 10th percentile and fat mass index > 25th percentile. We also assessed the erythrocyte sedimentation rate (ESR), C-reactive protein, Disease Activity Score in 28 joints, aerobic capacity, physical activity, traditional cardiovascular disease risk factors, functional disability, and sociodemographic data. Associations between RC and the independent variables were determined with logistic regression analyses.

The prevalence of RC was 24%. RC was significantly associated [odds ratio (95% confidence interval)] with aerobic capacity [0.28 (0.09-0.89), p = 0.030], low-intensity physical activity [0.77 (0.60-0.99), p = 0.048], body mass index [0.78 (0.70-0.92), p = 0.002], waist circumference [0.96 (0.92-0.99), p = 0.023], body weight [0.94 (0.90-0.98), p = 0.004], and ESR at the time of diagnosis [1.02 (1.00-1.05), p = 0.033]. All of these associations remained significant after adjusting for age and gender.

RC was highly prevalent in early RA. Patient outcome may be improved by detecting this condition early and applying treatments for improving inflammation, aerobic capacity, physical activity, and body composition.