To analyze the influence of cyclosporine A (CYA) on bone using data from a large multicenter, cross-sectional study on bone mineral density (BMD) in rheumatoid arthritis (RA).
We selected 558 female patients with RA and divided them into two groups on the basis of CYA use: those who had never used CYA (n = 467) and CYA users (n = 91; users for < 24 months n = 50; users for > 24 months n = 41). Demographic, disease and treatment-related variables were collected for each patient. BMD was measured at the lumbar spine and proximal femur using dual x-ray absorptiometry. Data was analyzed by means of a univariate and multivariate statistical procedure. Osteoporosis (OP) was defined as BMD < -2.5 T score.
The frequency of OP among non-CYA users and CYA users was 28.2% and 33.3% (p=NS) for the lumbar spine, and 34.2% and 31.3% (p=NS) for the femoral neck, respectively. The prevalence of fragility fractures was not significantly different between the two groups. Mean values for the T-score at either the lumbar spine or the femoral neck were comparable in the two groups, even after adjustment for age, menopausal status, body mass index (BMI), Health Assessment Questionnaire (HAQ) score and steroid use. The generalized linear model showed that age, BMI and the HAQ score were significant independent predictors of BMD at the lumbar and femoral levels, whereas CYA use was not. Logistic analysis showed that only age, the HAQ score and BMI were significantly associated with the risk of OP. However, the duration of CYA therapy > 24 months was associated with an adjusted decreased lumbar BMD and a significantly decreased femoral neck BMD (p = 0.01). The frequency of femoral neck OP in patients on CYA for > 24 months was significantly higher than in patients on CYA for < 24 months: 46.4% vs. 19.44% (p=0.03), while the prevalence of fragility fractures did not differ significantly: 23.1% vs. 16.6%, respectively (p=NS). Logistic analysis showed that CYA use was an independent predictor of osteoporosis at the femoral site.
Long-term CYA therapy may have negative effects on BMD in female RA patients.