To investigate the prevalence of osteopenia/osteoporosis in a group of men with rheumatoid arthritis (RA); and to analyze the relationship between sex hormone status and bone mineral density (BMD), taking into account disease activity, disease duration, and corticosteroid intake.
Clinical and demographic details were collected on 50 consecutive men with RA. BMD at the lumbar spine and femoral neck were measured, together with plasma concentrations of testosterone, sex hormone binding globulin, and luteinizing hormone.
The median age of patients was 67 years, with median disease duration 20 years. Fourteen patients had never been treated with oral corticosteroids, the remaining 36 received a range of prednisone doses over prolonged periods. Plasma testosterone concentration was moderately reduced in 40% (< 10 nmol/l) and severely reduced in 6% of men (< 8 nmol/l), but androgen deficiency was not related to bone density or fractures. Spinal and femoral neck BMD was reduced in 38 and 71% of the men, respectively. Femoral neck BMD was related to age, weight, disability status, and specific disease activity scores. The only predictors of spinal BMD were pack-years of smoking and physician global assessment.
Reduced BMD is common among men with RA. The predictors for spine and femoral neck BMD bear little direct relationship to blood testosterone concentrations despite the relatively high prevalence of low testosterone concentrations in this population. These findings are more consistent with the possibility that low testosterone concentrations in men with RA are a bystander effect of systemic inflammatory disease.