Tuesday, May 6, 2008

Osteoporosis and Gene Tests

Osteoporosis, or porous bone, is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures, especially of the hip, spine and wrist, although any bone can be affected.In simpler terms, osteoporosis is a condition in which the bones become weak and can break from a minor fall or, in serious cases, from a simple action such as a sneeze.

About 85-90% of adult bone mass is acquired by age 18 in girls and 20 in boys. Building strong bones during childhood and adolescence can help to preventosteoporosis later in life.

In the U.S. today, 10 million individuals are estimated to already have the disease and almost 34 million more are estimated to have low bone mass, placing them at increased risk for osteoporosis.

In 2005, osteoporosis-related fractures were responsible for an estimated $19 billion in costs.By 2025, experts predict that these costs will rise to approximately $25.3 billion

So I ask you.....if we could prevent osteoporosis wouldn't we. Early detection and identification of at risk populations is key. Recently there were some great studies that came out of Lancet and the NEJM identifying patients which might be at risk. They are definitely associated in some sort of way, but not ready for prime time. Why? Because there are better predictors


Significant risk has been reported in people of all ethnic backgrounds.
Twenty percent of non-Hispanic Caucasian and Asian women aged 50 and older are estimated to have osteoporosis, and 52 percent are estimated to have low bone mass.

So more often in Asian and Caucasian women. What are other risk factors?

  • Being female

  • Older age

  • Family history of osteoporosis or broken bones

  • Being small and thin

  • Certain race/ethnicities such as Caucasian, Asian, or Hispanic/Latino although African Americans are also at risk

  • History of broken bones

  • Low sex hormones

  • Low estrogen levels in women, including menopause

  • Missing periods (amenorrhea)

  • Low levels of testosterone and estrogen in men

  • Diet
    Low calcium intake
    Low vitamin D intake
    Excessive intake of protein, sodium and caffeine

  • Inactive lifestyle

  • Smoking

  • Alcohol abuse

  • Certain medications such as steroid medications, some anticonvulsants and others

  • Certain diseases and conditions such as anorexia nervosa, asthma and others

  • Loss of height (which may indicate a spinal fracture)

So what does genetic testing add to this? From the clinical side....Absolutely Nothing. The risk prediction from these above factors is much higher than the non-statistical significance genes in the New England Journal of Medicine. Nor the interesting findings in the Journal Lancet.

The Sherpa Says:

Listen, back to the basics before we hype up these SNPs in Lancet. Odds Ratios less than 2.0 are not very useful for clinical practice.....So why do they get all this hype???? Because "New Gene For X" Always makes headlines and sells papers.


Waqas said...

So why do they get all this hype???? Because "New Gene For X" Always makes headlines and sells papers.

An article from yesterday's guardian that elaborates this point:

Berci Meskó said...

This is so so true, Steve!

You should see how many "Scientists found the gene for ..." articles are being published in Hungary...

Steve Murphy MD said...

Thanks for the article.

"New Gene" always sells.

When can I get the critical thinking gene discovered?