Effects of low calcitonin doses on bone remodeling in postmenopausal womenwith high bone turnover rate

Background: Calcitonin is specially indicated for the treatment of osteopor osis ill women that cannot receive estrogen replacement therapy or that hav e a high bone turnover rate. Aim: To study the effects of low intranasal ca lcitonin doses on bone remodeling in postmenopausal women with a high bone turnover. Patients and methods: Forty one healthy women aged 56 +/- 6 years old, with a mean lapse after menopause of 7.6 +/- 6.5 years and with a hig h bone turnover rate, evidenced by an urinary hydroxyproline (mg/dl)/creati nine (g/dl) ratio of 52.4 +/- 7.2, were studied. They were randomly assigne d to receiive 100 or 50 U/calcitonin thrice a week during 3 months or to a control group that received placebo. All received 500 mg/clay calcium carbo nate. Urinary hydroxyproline/creatinine ratio was measured a 0, 15, 30, 60 and 90 days. Plasma bone fraction of alkanine phosphatases was measured at 0, 30 and 90 days. Results: Initial urinary hydroxyproline/creatinine ratio and plasma bone fraction of alkanine phosphatases were similar in all stud y groups and there was no change in these parameters during the study perio d. Conclusions: Intranasal calcitonin in doses of 100 U thrice a week or le ss, does not modify accelerated bone turnover in postmenopausal women.