Bone mineral density in premenopausal systemic lupus erythematosus patients: influence of serum leptin, disease related variables and use of corticosteroids

ABSTRACT

To evaluate bone mineral density [BMD] in premenopausal female patients with SLE and to assess the influence of serum leptin, disease related variables and use of corticosteroids. We analyzed only the premenopausal SLE patients to eliminate the confounding effect of menopause on bone loss. Forty pre-menopausal systemic lupus erythematosus patients [SLE] who fulfilled the revised criteria for classification of SLE of the American College of Rheumatology [ACR] and twenty healthy control subjects apparently free from any relevant disease were included in this study. All patients were subjected to full history taking, thorough clinical examination and assessment of disease activity using the SLE disease activity index [SLEDAI], assessment of functional status using Steinbrocker grades as well as measurement of serum leptin level with ELISA. Bone densitometry was performed by Dual Energy X-Ray Absorptiometry [DEXA] at the lumbar spine from L2-4 and left hip [femoral neck, trochanter]. Our results showed a high frequency of low BMD at the lumbar spine [L2-L4] and left hip [femoral neck, trochanter] as diagnosed by using DEXA in premenopausal female patients with SLE as compared to controls. BMD correlated negatively with age, disease activity, functional capacity, and corticosteroid treatment and correlated positively with bone mass index [BMI] and serum leptin level. Premenopausal SLE patients had significantly lower BMD than controls. Also, a high incidence of osteopenia and osteoporosis was found in premenopausal patients with SLE. Bone diminution in SLE seemed to be attributable to age, BMI, disease activity, functional capacity and serum leptin level and corticosteroid treatment. Regular DEXA screening, controlling of disease activity, improving of functional capacity and reduction of steroid dose as much as possible may be of beneficial effects upon BMD in SLE patients. Leptin may be useful in the future for further research in the treatment of osteoporosis