What is osteo

Osteoporosis

What is osteoporosis?
Medical vs Health Perspective

What is osteoporosis?

The word "osteoporosis" simply means "porous bones". In the past, osteoporosis was diagnosed only after a person broke a bone in a situation in which normal, healthy bone would not be expected to break. As example of this would be a simple fall. Nowadays, the most common way to diagnose osteoporosis is by measuring bone mineral density (BMD). The bones most likely to break from osteoporosis are the vertebrae, the wrist, and the hip.

Medical vs health perspective on osteoporosis

There are many factors involved in the development of osteoporosis. The medical perspective, however, argues that the lower amount of estrogen associated with menopause is the primary cause and advocates the life-long use of estrogen as the best strategy for prevention. The acceleration of bone loss for about 5 years around the time of menopause and the fact that most studies show that women who take estrogen maintain their bone density as long as they continue taking this drug are used to support this position.

The health perspective argues that there are many factors, far more important than menopause, in the development of osteoporosis and that strategies other than estrogen should be advocated. The tremendous variation of fracture rates among and within countries is used to support this position.

The chart below gives some examples of this variation. The numbers refer to hip fractures per 100,000 per year. (1)

Population	Women	Men
Norway Whites (Central)	1293	551
US Whites (California)	622	291
US Blacks (California)	219	144
Beijing, China	88	97

I recently presented a paper in Tromsø, Norway using the above data. Women in the audience asked me why Norwegian women are at such high risk for hip fractures. I told them the reason is not well understood because very little research has been done exploring this issue.

I learned that Norwegian women are told by their physicians that their high rates are due to menopause and they need to take estrogen to reduce their risk, the same as what U.S. women are told. Yet, as you can see in the above chart, Norwegian women have about twice the rate as U.S. white women and U.S. white women have a seven times higher rate than Beijing women, and all of us experience menopause. Not incidentally, U.S. white men have somewhat higher rates of hip fractures rates than U.S. black women and more than 3 times that of Beijing women. Surely other factors much more important than hormonal levels are responsible for hip fractures. These factors need to be discovered so that women (and men) can have the information needed to reduce their own risks.

(1) Xu Ling, Lu Aimin, Zhao Xihe, Chen Xiaoshu, Steven R. Cumming. Very low rates of hip fracture in Beijing, People's Republic of China: The Beijing Oseoporosis Project. Am J Epidemiol 1996; 114: 901-7.