Evaluation of bone mineral density and vitamin D in patients with systemic lupus erythematosus and their relation to disease activity

Background Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that affects multiple systems and is associated with an inflammatory status. The aim of our study is to estimate the serum level of vitamin D and bone mineral density (BMD) in SLE patients and their relation to disease activity. Patients and methods Ninety SLE patients, fulfilling the updated American College of Rheumatology criteria 2012 and 60 age-matched and sex-matched controls were included in this study. The level of serum 25-hydroxyvitamin D (25(OH)D3) and dual-energy radiograph absorptiometry were done for patients and controls. Results There was significant difference between systemic lupus erythematosus disease activity index (SLEDAI) score and vitamin D (P 0.02). There were significant difference (P 0.01) between SLE and control with BMD of total lumbar (L1–L4) and total hip and highly significant difference (P 0.001) with neck of the femur, Ward’s angle of the femur, trochanter of the femur, and the radius. There was significant difference (P 0.05) between SLE and control groups regarding T score of lumbar spine (L1–L4) (P 0.03), neck of the femur (P 0.01), and total hip bone (P 0.02). Our results showed that there was significant difference between SLEDAI score and T score of neck of the femur (P 0.02) and radius bone (P 0.012), while there was no significant difference between SLEDAI score and T score of total hip, lumbar spine (L1–L4), Ward’s angle of the femur, and the trochanter of the femur. Conclusion Vitamin D deficiency and low BMD are common in SLE patients. There was significant difference between SLE patients and control group regarding vitamin D, BMD, and T score at different sites.