by Marcelle Pick, OB/GYN NP
The brief acceleration of bone loss (also called resorption) that every woman experiences during menopause indicate that a dip in estrogen levels promotes bone resorption—and research has borne this out. It’s one reason many doctors prescribe Hormone Replacement Therapy (HRT). Furthermore, evidence shows that low doses of estrogen does slow bone loss, inhibiting osteoclast activity, but plateaus at about seven years post-menopause. What’s more, progesterone seems to be just as beneficial for bone formation, encouraging osteoblast activity.
However, once HRT is discontinued, bone loss accelerates to reach its age-appropriate rate. Most of these studies are rarely carried out for longer than a few years, at which point bone loss may have stabilized itself. So HRT may hold the train at the station, but it will eventually depart. And there’s no indication that HRT therapy has any long-term effect on fracture risk in women over 75—when most fractures occur.
Remember that bone function is a two-way street; if resorption is delayed, then so is formation—so no bone is lost, but no new bone is made. What effect does this have on bone strength (an answer the makers of Fosamax have yet to discover). No studies have been done to examine what the long-term side effects on bone are following HRT therapy.
Evista (raloxifene) is a selective estrogen receptor modulator similar to tamoxifen. It is often prescribed to women with osteoporosis. Developers claim it reduces fractures without the risks of HRT. Side effects include increased hot flashes, leg cramps, flu-like symptoms, blood clots and peripheral edema, among others.
What’s appears to be more important is to promote your bodies natural hormonal balance throughout adulthood so that bone growth stays consistent or only slightly slower than bone loss. This can be difficult during perimenopause, when progesterone levels fluctuate, or if you’ve had your ovaries removed at an early age.