ACUTE EFFECTS OF NASAL SALMON-CALCITONIN ON CALCIUM AND BONE METABOLISM

Effects of a single dose of 200 IU of nasal salmon calcitonin (SCT) on calcium metabolism and biochemical markers of bone turnover were investigated in 12 healthy male volunteers in a randomized, placebo-controlled, cross-over design. The nasal spray was given in the morning, and subsequently blood and urine samples were collected for 26 hours. There was a significant decrease in serum ionized calcium with a nadir 4 hours after administration of nasal SCT accompanied by a significant increase in serum parathyroid hormone (P = 0.01) and serum calcitriol (P = 0.04). Nasal SCT did not reduce urinary hydroxyproline/creatinine. Urinary deoxypyridinoline/creatinine was lowered significantly 2 hours after administration of nasal SCT and throughout the first 24 hours, but remained unchanged for the last 2 hours. On a 24-hour basis, urinary deoxypyridinoline/creatinine decreased from 14.1 (3.5) nmol/mmol to 11.7 (3.2) nmol/mmol after nasal SCT (P = 0.04). Nasal SCT did not change the serum levels of alkaline phosphatase, osteocalcin, and the carboxyterminal propeptide of type 1 procollagen. The results indicate that nasal SCT given as a single dose provokes a modest decrease in bone resorption lasting several hours, but leaves bone formation unaffected.