Serum osteocalcin concentrations in Paget's disease of bone

Total body scintiscans, serum alkaline phosphatase estimations, and serum osteocalcin radioimmunoassays were performed in 49 consecutive patients with Paget's disease of bone. Eleven were receiving calcitonin (salmon synthetic) at the time of the study. The serum alkaline phosphatase activities were elevated in all but one patient, with the highest value almost 50 times the upper limit of the reference range. Serum osteocalcin concentrations were elevated in 53% of patients and normal in the rest. The highest serum osteocalcin value was 4.2 times the upper limit of the reference range. The correlation coefficient between the extent of skeletal involvement and serum osteocalcin level was .70, while that between skeletal involvement and serum alkaline phosphatase level was .55. In spite of the better correlation between bone scintiscans and serum osteocalcin level, osteocalcin measurements are diagnostically less useful than serum alkaline phosphatase estimations in patients with Paget's disease of bone.