Changes to Body Composition in Women With Long-Standing Established Rheumatoid Arthritis: Differences by Level of Disease Activity.

INTRODUCTION: Few studies on rheumatoid arthritis have investigated disease activity and body composition by dual-energy X-ray absorptiometry including evaluation of visceral adipose tissue. Thus, we sought to verify the association between body composition by dual-energy X-ray absorptiometry, including visceral adipose tissue, and inflammatory activity in long-standing established rheumatoid arthritis. METHODS: Seventy-eight postmenopausal women with rheumatoid arthritis (American College of Rheumatology 2010) were studied. Disease activity was assessed by composite indexes (DAS28, CDAI, SDAI) and C-reactive protein. Potential association between body composition and disease activity was analysed by Pearson correlation and Tukey´s test (p < 0.05). RESULTS: There was significant negative correlation between C-reactive protein and appendicular lean mass index (r = -0.234, p = 0.039). After adjusting for confounding variables, women with C-reactive protein >10 mg/L had a lower appendicular lean mass index than those with C-reactive protein 5-10 mg/L and <5 mg/L (6.3 ± 0.8 kg/m2 vs 7.2 ± 1.2 kg/m2 vs 6.8 ± 1.0 kg/m2, respectively; p = 0.013). Women with moderate inflammation (C-reactive protein 5-10 mg/L) had more fat than those with C-reactive protein >10 mg/L and C-reactive protein <5 mg/L (12.4 ± 3.5 kg/m2 vs 9.9 ± 3.6 kg/m2 vs 10.5 ± 2.8 kg/m2, respectively; p = 0.040), as well as more visceral adipose tissue than women with higher and lower C-reactive protein (812.5 ± 266.4 cm3 vs 604.3 ± 236.3cm3 vs 658.9 ± 255.6 cm3; p = 0.009). CONCLUSIONS: High inflammatory activity that persists after a long disease duration was associated with both lower muscle and fat mass (including visceral adipose tissue), which is suggestive of more exuberant rheumatoid cachexia. Conversely, moderate activity was associated with greater visceral adipose tissue, which is associated with increased cardiovascular risk. These results point to the existence of different body composition profiles according to inflammatory status and the importance of individualized approaches to muscle mass and adiposity according to disease activity level in long-standing rheumatoid arthritis.