ISSN:
1433-2965
Keywords:
Key words:Calcitriol therapy – Calcium absorption – Hormone replacement therapy – Osteoporosis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract: In a randomized trial involving 71 postmenopausal osteoporotic women with vertebral compression fractures, radiocalcium absorption studies using the 45Ca single isotope method (α) were performed at baseline and after 8 months of treatment with either continuous combined hormone replacement therapy (HRT, as piperazine estrone sulfate 0.625–0.937mg daily ± medroxyprogesterone acetate 2.5 mg daily depending on uterine status) or HRT plus calcitriol 0.25 μg twice daily. A calcium supplement of 600 mg nocte was given to only those women who had a daily calcium intake of less than 1 g per day at baseline, as assessed by recalled dietary intake. There was a significant decrease [0.74 (± 0.35 SD) to 0.58 (± 0.22), Dα=−0.17 (± 0.26), p〈0.0005] in α at 8 months compared with baseline in the HRT-treated group, but a significant increase [0.68 (± 0.31) to 0.84 (± 0.27), Dα=+0.16 (± 0.30), p〈0.003] in the HRT-plus-calcitriol treated patients, resulting in α being significantly higher after 8 months in the latter group than in the HRT-only group. Although 72% of the patients had been supplemented with calcium between the first and second studies, separate analyses revealed that the change in calcium intake had not affected the result. Further breakdown of the groups into baseline ‘normal’ absorbers (α≥0.55) and ‘malabsorbers’ (α 〈0.55) revealed that α decreased with HRT treatment only in the normal absorbers, and remained stable in the malabsorbers. Conversely, following HRT plus calcitriol treatment, α increased only in the malabsorbers, the normal absorbers in this group remaining unchanged. In conclusion, our data show that HRT, of the type and dose used in this study, did not produce an increase in absorption efficiency; it was in fact associated with a fall. Increased absorption efficiency cannot be achieved unless calcitriol is used concurrently, and then only in patients with malabsorption. Calcitriol also had a significant effect in normal absorbers in that it prevented the decline in α seen with HRT alone, and thus should be considered in all patients with postmenopausal osteoporosis treated with HRT.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s001980050005
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