Prevalence and Possible Risk Factors of Low Bone Mineral Density in Untreated Female Patients with Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by chronic inflammation. Different studies have shown decreased bone mineral density (BMD) in patients with SLE. The objective of this study was to investigate the prevalence and possible risk factors of low BMD in untreated female patients with SLE in Chinese population. A total of 119 untreated female patients with SLE were included. BMD was measured at lumbar spine and at total hip by dual-energy X-ray absorptiometry. The associations between decreased BMD and demographic variables, clinical variables, and bone metabolism variables were analyzed. These SLE patients had the following characteristics: mean age was 32.6 ± 11.9 years, mean disease duration was 22.1 ± 34.5 months, and mean SLEDAI was 11.4 ± 5.4. Osteopenia was present in 31.1% of the patients and osteoporosis in 8.5%. A significant negative association between low density lipoprotein cholesterol (LDL-c) and BMD at the lumbar spine (correlation coefficient = −0.242; P = 0.023) and total hip (correlation coefficient = −0.259; P = 0.019) was shown. These results seem to indicate that increased LDL-c may be an important risk factor for low BMD at lumbar spine and total hip in untreated female SLE patients.