Serum osteocalcin in patients with rheumatoid arthritis

Objective To determine serum osteocalcin concentration in patients with rheumatoid arthritis (RA) and study the role of osteocalcin in bone metabolism.Methods Serum concentration of osteocalcin was determined by radioimmunoassay both in 32 patients with RA and 15 healthy controls. Erythrocyte sedimentation rate (ESR) and serum activity of alkaline phosphatase (ALP) were also determined.Results Serum osteocalcin concentration was significantly lower in patients with RA than that in the controls (P0.001).No significant difference in serum concentration of osteocalcin between women aged less than 50 years and those aged equal to or more than 50 years in both groups was found (P0.05). There was no significantly linear correlation between serum osteocalcin and ESR,ALP and duration of disease course in patients with RA (P0.05).There was a significant positive correlation between serum osteocalcin and ESR in female patients with RA aged less than 50 years (P0.05).Conclusions Serum osteocalcin concentration significantly decreased in patients with RA,suggesting reduced osteoblastic activity and rate of bone turnover.There is no correlation between serum osteocalcin and ESR,ALP or the disease course.