Age-Related Changes of Calcitonin Secretion in Females*

Calcitonin secretion was studied in 50 normal females from 20--69 yr of age, with 10 subjects in each decade. Hormone measurements were made by RIA during response to a 10-min infusion of calcium (as the chloride salt) at 3 mg/kg BW. There was a progressive decrease of the calcium-stimulated plasma calcitonin with age. Linear regression analysis demonstrated a significant (P less than 0.05) negative correlation (r = 0.29) between calcitonin response and age. Postmenopausal females had a significantly (P less than 0.01) smaller calcitonin response than premenopausal females. The time of maximum calcitonin response progressively shifted from 10 min in the younger subjects to 20 min in the older subjects. These studies demonstrated that calcitonin secretion decreases with age in females. This decrease may play some role in the pathogenesis of the progressive loss of bone mass which occurs with aging in females.