Bone mineral density in women with systemic lupus erythematosus

The aim of this cross-sectional study was to determine the prevalence of reduced bone mineral density (BMD) in a group of female SLE patients and to identify factors predictive of reduced BMD. Femoral neck (FN) and lumbar spine (LS) dual-energy X-ray absorptiometry results were evaluated in 79 pre- and postmenopausal women with SLE aged (mean, range) 49 (22-73) years). Variables evaluated were disease duration, SLEDAI, current and cumulative corticosteroid dose, Steinbrocker's functional classification, use of immunosuppressive agents, and history of fracture due to minor trauma. A T-score of < or = 1.0 was found in 61.9% at the LS and 48.3% at the FN, and 18 (23.7%) patients belonged to the category of osteoporosis at LS, compared to only three (5.4%) patients at FN. A statistical difference (P = 0.014) was found when comparing LS BMD in pre- and postmenopausal patients. LS BMD had a significant correlation with daily and cumulative steroid dose (P = 0.016 and 0.031, respectively). There was a significant difference in LS BMD between the daily steroid dose group receiving < or = 7.5 and those receiving > 7.5 mg/day (P = 0.008), and also in FN BMD comparing groups on 0 and > 7.5 mg/day (P = 0.022). There was significant difference in LS and FN BMD between patients in Steinbrocker classes I and III (P = 0.016 and 0.005, respectively). No significant correlation was found in either subgroup between BMD and other studied parameters. We concluded that the prevalence of reduced bone mass at LS is pronounced among postmenopausal women with SLE, in those with a high Steinbrocker functional classification and those on a high daily steroid dose. Therefore, these patients should be considered as a high-risk group deserving regular spinal BMD scans and therapy in time to prevent vertebral fractures.