I've attached the abstract available on Medline for this particular article. Note the date and strong caveat about making any assumptions about progesterone and bone from this particular research. A recent article pretty much disposes of any notion of osteoporosis as a disease of women of any age since the results of a recent study in Canada finds that osteoporosis is an equal opportunity disease found equally in both men and women. See: http://www.theglobeandmail.com/health and scroll down to the 7 day search box. Put osteoporosis in as your search term. Some quotes from the story: > > The findings of the Canadian Multi-Centre Osteoporosis Study, a program involving almost > 10,000 participants in nine centres across Canada, will almost certainly change the way > medical professionals deal with unexplained bone fractures in men and the way education > about the condition is handled. > > "We didn't think that men fractured," Jonathan Adachi, a rheumatologist and professor of > medicine at St. Joseph's Hospital and McMaster University, said yesterday. > > "This was unheard of in the past. No one had looked at it [osteoporosis in men] with any > seriousness. We used to think that when men fractured their hips, it was due to trauma or > long-time alcohol use, which can weaken bone density." > The study involved x-rays and bone scans on 3,000 men and 6,000 women over the age of > 50. It showed 25 per cent of the men have osteoporosis, which showed itself as spinal > fractures. The figure was the same for women. and > Osteoporosis, a condition of brittle bones caused by bone tissue loss, can be the result of > hormonal changes or lack of calcium. In the past, the condition was believed more common > in women than men because of hormonal changes during menopause. > > This new study is likely to change that belief, and with it the way health professionals educate > their patients about the disease. It should also be noted that Prior never endorsed the use of otc progesterone creams as a treatment for osteoporosis and that most of the sites selling this snake oil (including the "Women's International Pharmacy" have taken a few sentences of her research out of context in an attempt to make their case sound more scientific. Progesterone as a bone-trophic hormone. Prior JC Endocr Rev 1990 May 11:386-98 BROWSE : Endocr Rev • Volume 11 • Issue 2 VIEW : MEDLINE, full MEDLINE, related records Abstract Experimental, epidemiological, and clinical data indicate that progesterone is active in bone metabolism. Progesterone appears to act directly on bone by engaging an osteoblast receptor or indirectly through competition for a glucocorticoid osteoblast receptor. Progesterone seems to promote bone formation and/or increase bone turnover. It is possible, through estrogen-stimulated increased progesterone binding to the osteoblast receptor, that progesterone plays a role in the coupling of bone resorption with bone formation. A model of the interdependent actions of progesterone and estrogen on appropriately-"ready" cells in each bone multicellular unit can be tied into the integrated secretions of these hormones within the ovulatory cycle. Figure 5 is an illustration of this concept. It shows the phases of the bone remodeling cycle in parallel with temporal changes in gonadal steroids across a stylized ovulatory cycle. Increasing estrogen production before ovulation may reverse the resorption occurring in a "sensitive" bone multicellular unit while gonadal steroid levels are low at the time of menstrual flow. The bone remodeling unit would then be ready to begin a phase of formation as progesterone levels peaked in the midluteal phase. From this perspective, the normal ovulatory cycle looks like a natural bone-activating, coherence cycle. Critical analysis of the reviewed data indicate that progesterone meets the necessary criteria to play a causal role in mineral metabolism. This review provides the preliminary basis for further molecular, genetic, experimental, and clinical investigation of the role(s) of progesterone in bone remodeling. Much further data are needed about the interrelationships between gonadal steroids and the "life cycle" of bone. Feldman et al., however, may have been prophetic when he commented; "If this anti-glucocorticoid effect of progesterone also holds true in bone, then postmenopausal osteoporosis may be, in part, a progesterone deficiency disease." |