Body composition in patients with rheumatoid arthritis

2. SUMMARY BODY COMPOSITION IN PATIENTS WITH RHEUMATOID ARTHRITIS Key words: Arthritis, rheumatoid, body composition, obesity Purpose: Changes in body composition (reduced lean body mass, bone mineral content [BMC] and increased fat mass) in rheumatoid arthritis (RA) have been reported previously. It has been suggested that decreased lean body mass and increased total body fat were related with increased morbidity and mortality in patients with rheumatoid arthritis. This has been explained by changes in cytokine and hormone production and also by decreased physical activity. However, in these studies age and sex but not body mass index (BMI) matched controls were used. Primary objective of this study was to evaluate body composition in RA patients and compare it with age, sex, and BMI matched controls. As body composition changes may cause lipid metabolism disturbances, we also investigated lipid profiles in our patient and control groups and if they were related with body composition parameters. Methods: Sixty-six RA patients (ACR 1987) (56 female and 10 male; mean age 55.14 ± 10.8) and 31 healthy controls (25 female, 6 male; 53.8 ± 8.6) were included in this study. Mean disease duration for RA patients was 9.2 ± 9.6 years and mean ACR functional class was 2.3 ± 1.0. Body composition was measured by anthropometrically, bioimpedance analysis and dual-energyX-ray absorbsiometry (DEXA). Visceral adipose tissue (VFA) was assessed with computed tomography. Results: There was no significant difference between the patient and control groups regarding to BMI (27.5 ± 4.8 vs 28.1 ± 4.8 kg/m2 respectively), total body fat percent (36.3 ± 8.0 vs 35.4 ± 7.8 respectively), lean mass percent (mean 60.9 ± 8.5 vs 61.9 ± 7.8 respectively) and visceral fat area (VFA) (144.2 ± 41.4 cm2 vs 145.9 + 49.4 cm2 respectively). BMC was found to be significantly lower in RA patients (mean BMC in pateints 1805.2 + 358.8 g vs in controls 2074.0 ± 295.8 g; p=0.004). Although serum levels of cholesterol, low density lipoproteins and triglycerides were not different between the patient and control groups, serum levels of high density lipoproteins (HDL) were significantly high in patients (63.9+14.7 mg/dl vs 50.5+13.7 mg/dl respectively; p<0.0001). Conclusion: Factors other than body composition should be related with excess mortality and morbidity in patients with rheumatoid arthritis.