Body composition in rheumatoid arthritis.

The objectives were to assess bone mineral density (BMD) at different body sites in rheumatoid arthritis (RA) patients related to disease severity parameters, disease duration and corticosteroid intake, and to look for body composition measurements as lean body mass (LBM) and per cent fat as possible prognostic factors in RA. Body composition values were measured cross-sectionally in 89 RA patients and compared with 157 controls. Patients were divided into males and postmenopausal females, ever steroid treated and never steroid treated. BMD values of all body sites were significantly lower compared to normals in all subgroups, except for the lumbar spine (L2 L4) in all postmenopausal women and males never treated with steroids. There was also no clear BMD decrease in the arms of male RA patients. LBM was significantly lower in all body parts compared to controls, whereas the fat distribution ratio (FDR) showed a clear shift to abdominal in all patients. These are parameters of chronic illness and a predictor of cardiovascular disease, respectively. BMD data confirm our previous data in different patient groups (low at appendicular sites, normal lumbar BMD), but no clear influence of disease severity and steroid intake could be found. Body composition data, as LBM and FDR, are also altered in RA patients: decreased LMB and more central FDR. Their usefulness as prognostic markers in early RA patients needs to be clarified prospectively in these patient groups.