Assessment of fracture risk in a cohort of Egyptian female Systemic Lupus erythematosus patients

Aim of the work

To assess the fracture risk in a cohort of Egyptian systemic lupus erythematosus (SLE) females in correlation to some disease variables.

Patients and methods

Seventy female SLE patients ≥40 years old were enrolled with detailed history taking, assessment of disease activity and damage index. Measurement of Serum calcium, phosphorus and alkaline phosphatase, bone mineral density (BMD) by dual emission X-ray absorptiometry (DEXA) at lumbar spine (LS) and femoral neck (FN), serum osteocalcin level and World Health Organization (WHO) fracture risk assessment tool (FRAX®).

Results

20% of the patients had LS osteoporosis, 35.7% LS osteopenia, 8.6% FN osteoporosis, and 42.9% FN osteopenia. Ten-year risk of major and hip fractures was high in SLE patients evidenced by FRAX-Major ≥20% in 10% of patients, and FRAX-Hip ≥3% in 27.1% of patients. Serum osteocalcin level was significantly decreased in SLE patients with lower BMD than those with normal BMD, and significantly decreased in patients with osteoporosis than those with osteopenia. A significant negative correlation was found between osteocalcin level and age of patients, disease duration, disease activity and damage index scores, current intravenous pulse and cumulative steroids, immunosuppressants, anticoagulants, but there was a positive correlation with antimalarials and calcium supplements.

Conclusion

Ten-year risk of major and hip fractures was high in SLE patients. Increasing age, disease duration, high anti-DNA titres, higher disease activity and damage index were associated with a higher fracture risk. FRAX predicted fractures among SLE patients with normal and low bone mass not just those with frank osteoporosis. Physicians should be alerted to the higher risk of future fractures in SLE patients for periodic monitoring.