When the American College of Physicians (ACP) recently updated its guidelines for treating osteoporosis (Qaseem et al, 2017), tucked in with the usual recommendations for drug therapy was something major: The ACP reversed its position on estrogen therapy for osteoporosis.
In 2008, ACP guidelines supported estrogen therapy based on “high-quality evidence that estrogen therapy was associated with reduced risk for … fractures in postmenopausal women.” In direct contrast to this, the new guidelines state that “[m]oderate-quality evidence showed no difference in reduced fracture with estrogen treatment in postmenopausal women with established osteoporosis.”
How is it possible to have “high-quality evidence” that something works and a few years later, it somehow doesn’t? It’s all about how you look at the data. The 2008 guideline based its recommendation on studies showing estrogen decreased fracture risk—but, as the 2017 guideline points out, “many of these studies focused on postmenopausal women with low bone density, or on postmenopausal women in general rather than those with established osteoporosis.” In other words, the 2008 evidence came from women who did not have osteoporosis — the problem the guidelines are meant to address.
In the intervening years, a bunch of randomized clinical trials were done examining estrogen’s effects on women with osteoporosis to offer better information. Since estrogen offers little benefit and has known harms, like increased risk of stroke or breast cancer, the ACP’s decision to change their recommendation makes perfect sense. It also highlights two important points when it comes to science — one, it’s always changing with new information, and two, a lot depends on the assumptions of the people looking at the evidence.
It’s enlightening to look at the ACP osteoporosis guidelines side-by-side with the 2013 European Union osteoporosis guidelines (Kanis et al., 2013). The European recommendations start by discussing mobility, falls, and diet and nutrition before weighing the pros and cons of bone drugs. The ACP guideline starts with drug therapy and mentions nutrition only in passing (the usual suspects, calcium and vitamin D, nothing more) and devotes only three lines to exercise.
The ACP’s guideline assumes that drug therapy is the best approach. The Europeans look at it differently — and so do I. My Better Bones, Better Body approach has stayed pretty consistent over the years because it’s based on the understanding that the body knows how to heal itself if it has the resources it needs!
References
Qaseem A, Forceia MA, McLean RM, Denberg TD, for the Clinical Guidelines Committee of the American College of Physicians. Treatment of Low Bone Density or Osteoporosis to Prevent Fractures in Men and Women: A Clinical Practice Guideline Update from the American College of Physicians. Ann Intern Med 2017;166(11):818-839.