Prophylaxis of osteoporosis with calcium, estrogens and/or eelcatonin: comparative longitudinal study of bone mass

Objective: To evaluate three different therapeutic regimens for the prevention of osteoporosis in natural and surgical postmenopausal women who had been found to have rapid bone loss in analytical studies. Methods: A total of 104 naturally or surgically postmenopausal women were studied, and subsequently followed-up during 1 year for avoidance of the influence of seasonal variation on bone mass, a factor overlooked in several studies. They were randomized into four groups of 26 patients each: the untreated control group (mean age 50 ± 5 years); the hormonal replacement treatment (HRT) group (mean age 48 ± 6 years), which was treated for 24 days each month with transdermal 17β-estradiol, 50 mg/day, together with medroxiprogesterone, 10 mg during 12 days; the calcium group (mean age 50 ± 4 years), which was treated with elemental calcium, 1 g/day; and the calcitonin group (mean age 50 ± 5 years), which was treated for 10 days each month with eel calcitonin, 40 IU/day and with elemental calcium, 500 mg/day. Full-body bone densitometry, for measuring total body bone mineral content (TBBMC), was carried out in all the women at baseline and 1 year. TBBMC was corrected for body weight by dividing its value by body weight (TBBMC/W). Results: After 1 year TBBMC/W was lower in every group: −2.14% ( P < 0.001) in the control group; −0.14% ( P = NS) in the HRT group ( P < 0.05 vs. controls); −0.18% ( P = NS) in the calcium group ( P < 0.05 vs. controls); and −0.06% ( P = NS) in the calcitonin group ( P < 0.01 vs. controls; P < 0.05 vs. calcium and HRT). Conclusions: These findings show that all three treatments are effective in the prevention of postmenopausal loss of bone mass.