To quantify bone mineral density (BMD) in men with rheumatoid arthritis (RA) and to evaluate the influence of various disease-specific and non-disease-specific variables on bone mass.
Dual energy x-ray absorptiometry was performed in 104 male patients with RA and BMD was measured in lumbar spine, femoral neck, trochanter, and Ward's triangle. Inflammatory activity, measured as Disease Activity Score including 28 joints (DAS28), degree of functional impairment measured with the Health Assessment Questionnaire, and sex hormones (bioavailable testosterone, DHEAS, estradiol, and estrone) were estimated. Presence of erosions, rheumatoid factor, and current treatment as well as body mass index and smoking habits were recorded. Correlations were performed with nonparametric tests and multiple regression analyses.
BMD was reduced in both spine and hip compared to an age matched reference population. Erosive disease was the variable with the strongest correlation with BMD. Treatment with sulfasalazine correlated positively with BMD at 3 of the 5 measured bone sites. However, in multivariate analysis significance was sustained only in the trochanter region. There were no correlations between the degree of inflammation, levels of sex hormones, treatment with corticosteroids, or smoking and BMD at any site measured.
A large proportion of the men with RA had reduced bone mass. Sex hormone levels and treatment with corticosteroid did not influence BMD, nor did current degree of disease activity. Erosive disease was closely correlated with low BMD, whereas sulfasalazine was associated with high BMD at least in the trochanter region.