Characteristics of Bone Tissue in Postmenopausal Women with Systemic Lupus Erythematosus

Introduction. Osteoporosis is one of the most common systemic diseases of the skeletal system that is characterized by decreased bone mass per unit volume, increased bone fragility and risk of fractures. The prevalence of low bone mineral density in patients with systemic lupus erythematosus (SLE) is high, compared to the general population: osteopenia is diagnosed in 25.0–75.0 % of patients with SLE and osteoporosis – in 1.4–68.0 % of patients with SLE. According to the results of prospective studies, it was found that the combination of increases in bone resorption markers or bone formation markers in postmenopausal women with low bone mineral density (BMD) is associated with the increased risk of fractures – by a factor of 2.0–2.5. Aim. To characterize bone tissue in postmenopausal women with systemic lupus erythematosus. Materials and methods. SLE patients were randomized in the study, stratified by sex and postmenopausal status. 71 women (experimental group) aged 47 to 68 years (mean age at the time of the study – 54.08 ± 0.72 years) with SLE diagnosed according to the criteria set by the American College of Rheumatology (1982, 1997) were included in the study. The mean disease (SLE) duration was 13.83 ± 0.97 years; all the women at the time of the study were in postmenopausal status. 100.0 % of the patients received methylprednisolone at a dose of 8.0 to 24.0 mg/day (mean dose – 11.94 ± 0.55 mg/day) and calcium supplements at a daily dose of 1000.0 mg in conjunction with vitamin D supplement at a daily dose of 400.0 IU. The mean duration of glucocorticoid treatment in conjunction with calcium and vitamin D supplements corresponded to the mean duration of disease. The control group comprised 30 almost healthy women aged 49 to 62 years (mean age at the time of the study – 54.67 ± 0.79 years) in postmenopausal status. Two bone formation markers (osteocalcin and P1NP) and one bone resorption biochemical marker (β-crossLaps) were used to assess the rate of bone remodeling. The ultrasound bone densitometry of the calcaneus was conducted in order to evaluate the structural and functional state of bone tissue. The densitometry was performed using the ultrasound bone densitometer SONOST–2000 (OsteoSys Co., Ltd, Seoul, Korea). The statistical analysis was performed using Statistica 6.0 package (Stat Soft Inc, USA). Results and discussion. In all patients with SLE (100.0 %), changes in bone tissue were found: the first stage of osteopenia – in 16 patients (22.5