Osteoporosis and why we should all be thinking about it »
I am currently travelling in Japan, the country of tremendous beauty but also one where the prevalence of osteoporosis is quite high due to the genetically thinner bone of the people here as a whole. I figured, I’d write about osteoporosis in North America as it is actually very prevalent there as well.
What is osteoporosis? According to the 1991 Consensus Development Conference it is, ““A loss of bone mass and micro-architectural deterioration of the skeleton leading to increased risk of fracture.” There are 1.5 million fragility fractures every year, half with diagnosis of osteopenia which is a milder version of osteoporosis in the spectrum of bone density deterioration. It costs the U.S. more than 18 million dollars per year in health care costs and its incidence is increasing with our aging population.
Why is it important to you? The development of osteopenia and osteoporosis puts you at higher risk for fractures, many of which prevent you from doing the things you love. In fact, if you develop a hip fracture, you are at higher risk of death itself, due to complications from the fracture. This risk increases with the age at the time of the hip fracture. To understand why even children and young adults should be thinking about preventing osteoporosis, you have to understand how bone develops.
As we grow and age as children and young adults, our bone density and micro-architecture goes up, giving us stronger bones to allow our skeleton to carry more weight. Unfortunately, we achieve peak bone mass when we are around 30 years old. I usually tell patients that our bones are a reservoir for calcium. We have 30 years to most effectively fill that reservoir and after that we are able to focus merely on reducing the rate of bone density loss. Both women and men lose 0.4% of peak bone mass per year after age thirty. 70% of this process is genetic, 30% we can actually control.
What are the key risk factors? In order of the relative risk for hip fractures, the most dangerous type of fracture, they are: 1) parental history of hip fracture, 2) history of systemic steroid use like prednisone, 3) rheumatoid arthritis, 4) drinking more than 2 glasses of alcohol per day, 5) prior fracture after age 50, 6) current smoking, and 7) having a lower body mass index of 20 versus 25.
How is it measured? Bone density is usually measured with a machine called “Dual bean x-ray absorptimoetry (DEXA)” or rarely with a specific kind of quantitative computed tomography (qCT) machine. All post menopausal women and/or greater than age 60, as well as pre-menopausal women and men with risk factors should be screened. See your primary care physician or health care provider to discuss if this is appropriate for you.
My hope is to convince everyone to actively prevent osteoporosis and the resultant fractures. To do this we have to 1) maximize bone density if you are younger than 30, 2) prevent bone loss, and 3) prevent fractures. To maximize bone density, young adults and children should consume 1300mg of calcium and 200-800mg of calcium per day depending on age. Adequate vitamin D and weight bearing physical activity like running, walking or weight lifting are required as well to help stick the consumed calcium onto the bones.
To prevent bone loss, adults should consume 800 IU of Vitamin D and 1500 mg of Calcium per day as well as weight bearing physical activity. Everyone should avoid the risk factors that I listed above, especially systemic steroid use, excessive alcohol intake and smokers should aim to quit as soon as possible. Women who have irregular or missed menstrual periods need to discuss this with their primary care physician because it could be a sign of poor bone health as well.
To prevent fractures, those who have been diagnosed with osteopenia or osteoporosis should undergo formal or informal training for gait stability, use appropriate gait assistance like canes if needed, and make active fall precautions like reducing the number of stairs or landings in the home, avoid clutter on the floor and reduce the step over height in the shower or bath. Regular physical activity is critical, especially weight bearing exercises as listed above. Talk to your health care provider to see if screening is appropriate for you.
If you are diagnosed with osteopenia or osteoporosis, treatment is critically important to prevent fractures and death. Again, see your physician or health care provider to discuss treatment options.
References:
1) Bauer DC, Garnero P, Bilezikian JP, Greenspan SL, et al. Short-term changes in bone turnover markers and bone mineral density response to parathyroid hormone in postmenopausal women with osteoporosis. J Clin Endocrinol Metab 2006;91(4):1370-5.
2) Black D, et al. Once-yearly zolendronic acid for treatment of postmenopausal osteoporosis. N Engl J Med 2007;356:1809-22.
3) Consensus Development Conference: prophylaxis and treatment of osteoporosis. Am J Med 1991;90:107-10.
