Serum osteocalcin levels in normal subjects and patients with primary hyperparathyroidism

The serum concentrations of osteocalcin were measured by a radioimmunoassay method in 95 apparently healthy subjects of both sexes with ages from 20 to 80 years and in 16 patients with primary hyperparathyroidism. There were no differences for the values between healthy males and females before the age of fifty, whereas the levels were higher in postmenopausal females. The osteocalcin levels were inversely related to age in premenopausal females but not in elder females or in males. The serum osteocalcin levels were raised in patients with primary hyperparathyroidism but with a large overlap against normal values. In all groups there was a positive correlation with the serum alkaline phosphatases. Variations with age should be considered in the interpretation of measurements in females. Furthermore, the increase in the immediate postmenopausal period might have implications for postmenopausal bone loss.