[Bone mineral density and disease activity in untreated systemic lupus erythematosus patients].

OBJECTIVE: To determine the effects of disease activity and other risk factors on bone mineral density (BMD) in untreated systemic lupus erythematosus (SLE). METHODS: Lumbar and hip BMD were determined by dual energy X-ray absorptiometry (DXA) in 50 healthy controls and 120 premenopausal SLE females from Department of Rheumatology & Immunology, Third Hospital of Medical College of Jilin University during the period of 2010 - 2012. The SLE patients were divided into 2 groups, i.e. untreated and treated with glucocorticoid and immunosuppressives. Simple and multiple linear regression analyses were performed to determine the associations between BMD and disease-related variables. To completely eliminate the influences of glucocorticoid treatment on the results, the untreated SLE patients were chosen to investigate the risk factors with regression analysis. RESULTS: In femoral neck, greater trochanter and total hip, both the treated and untreated SLE patients had significantly lower BMD than the healthy controls (P < 0.01). In greater trochanter, the treated SLE group had significantly lower BMD than the untreated group. The BMD of left and right femoral neck of the former were botj -0.06 while that of the later -0.11 and -0.12 respectively (P < 0.05). Regression analysis showed that long disease duration and high (SLE disease activity index) SLEDAI were the risk factors of low BMD (P < 0.05), especially high SLEDAI. CONCLUSION: SLE itself may result in low BMD, especially in patients with high SLEDAI. Hip joints are predominantly affected. Long disease duration is also closely associated with low BMD in SLE.