Bone Mineral Density Change in Systemic Lupus Erythematosus: A 5-year Followup Study

Abstract

To determine changes of bone mineral density (BMD) over a 5-year period in a cohort of female patients with systemic lupus erythematosus (SLE) and to identify factors predictive of BMD loss. Our longitudinal study involved 125 female patients with SLE with a mean (SD) age of 46.5 years (10.1) and a median disease duration of 10.4 years. Demographics and clinical data were collected and BMD at the femoral neck, total hip, and lumbar spine (L1-4) was performed by using dual-energy x-ray absorptiometry at baseline and followup. Average percentage changes of BMD over a mean followup of 5 years were -2.41% at the femoral neck, -1.63% at the total hip, and -0.62% at the lumbar spine, with significant changes at both the femoral neck (p < 0.0001) and total hip (p < 0.0005), but not at the lumbar spine (p = 0.128). Disease flare, new organ damage, and use of glucocorticoids during followup were significantly associated with larger decreases in BMD. BMD loss was arrested at the femoral neck and BMD increased at the total hip and lumbar spine in patients receiving antiosteoporosis therapy. In multivariate analyses, use of antiosteoporosis therapy was independently associated with increased BMD at any site and new organ damage was an independent predictor of BMD loss at the femoral neck. Significant BMD loss at the hip over a period of 5 years was found in patients with SLE. Disease activity, disease damage, and use of glucocorticoids are the disease-specific variables that contribute to bone loss in SLE.