Bone mineral density in women with systemic lupus erythematosus, its association with bone turnover markers, levels of estradiol and interleukin-6

Abstract

Introduction: Osteoporosis is frequently diagnosed in patients with systemic lupus erythematosus (SLE). Potential causes and mechanisms of the development of this disease in patients with SLE are still being studied. Aim: To study bone mineral density (BMD) of women with SLE in Ukraine, evaluate its association with the level of bone turnover markers, interleukin-6 (IL-6) and serum estradiol levels. Material and methods: In total, 91 SLE women and 29 healthy individuals were examined. Apart from clinical risk factors for osteoporosis development, the levels of IL-6, bone formation and resorption markers, serum estradiol and their association with reduced BMD were evaluated. The deterioration of BMD was detected by dual-energy X-ray absorptiometry. Results and discussion: Reduced BMD in women with SLE is found in 35.2%. In the study group, 28 women with SLE (48.3%) have decreased levels of bone formation markers, while 30 women (51.7%) have increased bone resorption markers. Imbalance of bone metabolism is highly associated with the severity of the disease, IL-6, and an exposure dose of glucocorticoids. The level of estradiol in women with SLE is 1.8 times lower than in individuals from the control group. The deterioration of the BMD is closely related to the bone turnover disorder, level of IL-6 and estradiol. Conclusions: Independent predictors of BMD disorder in SLE women are levels of osteocalcin and C-terminal telopeptide of type I collagen as well as IL-6 and decreased level of serum estradiol.