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

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.

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 17 beta-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).

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).

These findings show that all three treatments are effective in the prevention of postmenopausal loss of bone mass.