Prevalence Of And Risk Factors For Low Bone Mineral Density In Patients With Systemic Lupus Erythematosus

Objective To determine the prevalence of and risk factors for low bone mineral density (BMD) in patients with systemic lupus erythematosus (SLE).And to measure the change in BMD during follow-up.Methods Two hundred and ten patients with SLE and seventy health controls were included. BMD at total hip, lumbar spine, and subdominant forearm distal area were measured by dual X-ray absorptiometry. Sixty two patients had been followed up. Demographic and clinical data including age, body mass index, menstruation status, age of onset, duration of SLE, clinical and serological profile, disease activity, duration of glucocorticoids (GCs) treatment, cumulative GCs dose, and anti-osteoporosis therapies were collected and analyzed.Results SLE patients were evaluated with a mean age of 34.7±11.6 years, duration of SLE 4.7±4.5 years, duration of glucocorticoids(GCs) treatment 3.4±4.1 years. The prevalence of osteopenia, osteoporosis, and vertebral compressed fractures in patients with SLE was 44.8%, 5.2%, and 1.9%, respectively, higher than that in the control group. Low BMD in femur and lumbar spine was more prevalent and severe than that in forearm. BMD decrease was more severe and more commonly seen in older, low body mass index (BMI), post-menopause, higher cumulative GCs doses and longer duration cases. The presence of anti-SSA, anti-SSB, anti-RNP, and anti-Sm are not associated with a low BMD. In multivariate analysis, low BMD in SLE was correlated with a low BMI, postmenopausal status, and higher cumulative prednisone doses. Postmenopausal status and juvenile-onset are correlated with low BMD in forearm. A 0.5～4 years follow up in 62 patients showed the BMD in the measured sites were not significantly decreased with the use of anti-osteoporosis therapies. Forty four (70.9%) patients'BMD increase or keep stable in lumbar spine, and 85.5%, 91.9% in left hip and subdominant forearm respectively. The patients with a decrease BMD in lumbar after follow-up had higher SLEDAI scores at baseline than the cases with BMD stable or increase. The average daily GCs does are not significantly different among the BMD decrease, BMD stable or increase patients during follow-up, but the cases with increase BMD were treated with more calcitriol.Conclusion Low BMD is commonly seen in SLE patients. The prevalence of osteopenia, osteoporosis was 44.8%, 5.2%. Low BMD was mainly seen at the hip and lumbar spine. The risk factors for low BMD are low BMI, postmenopausal status, and higher cumulative GCs doses. Furthermore, postmenopausal status and juvenile-onset are the risk factors for low BMD in forearm distal area. Anti-osteoporosis therapy is beneficial in avoiding BMD decrease.