BONE METABOLISM AND ITS REGULATION IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Abstract

Osteoporosis in ankylosing spondylitis (AS) may exacerbate pain and functional disorders and increases the risk of fractures. The mechanisms of its development in AS have not been adequately studied.Objective: to study bone mineral density (BMD) and its regulation in patients with AS.Subjects and methods. 70 patients (mean age, 43.2±9.2 years) with a documented diagnosis of AS (mean disease duration, 17.1±7.8 years) and a control group of 30 healthy individuals were examined. All the patients underwent estimation of BMD and the serum concentrations of osteocalcin, CrossLaps, and key regulators of osteoclastogenesis, such as osteoprotegerin (OPG) and a receptor activator of nuclear factor kappa-B ligand (RANKL) by an enzyme immunoassay. Results and discussion. In patients with AS, bone metabolism was characterized by a decrease in bone formation and by some increase in bone tissue degradation especially in high AS activity. These patients showed the elevated levels of the major blocker of osteoclastogenesis OPG and the OPG/RANKL ratio, which can cause the process of ossification characteristic of AS.

Keywords

• osteoporosis
• ankylosing spondylitis
• bone metabolism
• bone metabolism regulation