Osteoporosis in Systemic Lupus Erythematosus - Correlations with Disease Activity and Organ Damage

Purpose: to assess the incidence of osteoporosis in a cohort of SLE patients and to determine the possible correlations with disease activity, organ damage and glucocorticoid therapy. Material and methods: We analyzed a cohort that included 25 consecutive SLE patients, diagnosed according to ACR revised criteria, and 21 controls, with the same demographic characteristics. We assessed demographic, life style related, clinical, biologic and immunologic data; also, we registered information about the treatment and calculated disease activity and damage scores. Bone mineral density was measured both in lumbar spine and total hip, using dual-energy X-ray absorptiometry. Results: Evaluation of T score profile, both in lumbar spine and total hip, established a percentage of 36 (9) patients with osteoporosis, 40 (10) patients with osteopenia and 24 (6) cases with normal values. Mean T score in lumbar spine was -1.28+1.31 SD and for the total hip -1.21+1.34 SD. Analysis of correlation between T score, both in lumbar spine and total hip, and SLEDAI, established a moderate, negative correlation; for SDI we obtained a moderate correlation, both for lumbar spine and total hip, statistically significant. Conclusions: our results show an increased percentage of osteoporosis among SLE patients and a relation to disease and treatment variables, imposing a periodic evaluation, in order to establish an early diagnosis, the proper therapeutic measures, and to prevent the major consequence, vertebral and non-vertebral fractures.