Osteoporosis can be thought of as a 'weakening of the bones'. This weakening of the bones increases the risk of fracture. The ultimate goal of treating osteoporosis is to decrease the risk of fractures. Hip and spine fractures, especially in the elderly, can be debilitating and can decrease ones quality of life significantly.

Osteoporosis affects more than 10 million Americans over the age of 50. Osteoporosis results in 1.5 million fractures that contribute to the placement of 180,000 individuals into nursing homes annually. It also is thought to be responsible for greater than 500,000 hospitalizations annually. This number is expected to double or triple by the year 2020. Perhaps the most unsettling fact is that within one year of a hip fracture, 20% of these individuals will die¹.

Although we can not directly measure bone strength, we do have a test that comes close. By measuring bone mineral density (BMD), we can measure bone mass, which may account for approximately 70% of bone strength. Peak BMD is reached in the first 20 to 30 years of life². BMD is usually measured at the hip and/or spine. A BMD reading, or 'T score', shows us how our bone mass compares to that of a healthy, young, white, female.

Osteopenia

When it comes to T scores, the more negative the number, the greater the risk for osteoporosis. A normal T score reading is considered anything above -1. Anything less than -1 but greater than -2.5 is considered osteopenia. Osteopenia indicates a decrease in bone mass but not necessarily an increase in risk of fracture. Osteopenia is often a prescursor to osteoporosis.

Osteoporosis

A T score less than -2.5 indicates osteoporosis. Osteoporosis is characterized by an increased risk of fractures.

Screening for Osteoporosis

Luckily, there are guidelines for the early detection of osteoporosis. These guidelines were put forth by The National Osteoporosis Foundation (NOF).

Risk Factors

Risk factors are an important part of assessing your risk for osteoporosis. Recent data has shown that while BMD is a good indicator of osteoporosis risk, 82% of women who reported fractures had a T score higher than -2.5 and 67% had a T score higher than -2.0⁵. This data shows us that a T score alone should not be used to determine risk of osteoporosis. We must look also at the risk factors.

Prevention

 Prevention is key with osteoporosis. Once you have osteoporosis, it is difficult to undo. Although there are medications available, they are not necessarily a cure. The main class of medications used to treat osteoporosis, called 'bisphosphonates', help lay down a matrix within the bone to help strengthen it. Medications such as these have now been shown to decrease the risk of fracture, however, they can not get rid of the risk completely, therefore, prevention is key.

Exercise

There are many things you can do to prevent osteoporosis and the risk of fractures. First, the NOF recommends that we get adequate exercise. There are two main types of exercise that are especially beneficial when it comes to getting and keeping bone mass. The first is weight-bearing exercise. Weight-bearing exercises are those in which your bones and muscles work against gravity. This is any exercise in which your feet and legs are bearing your weight. Examples include jogging, walking, and stair climbing. Swimming or bicycling are not weight-bearing.

The second type of exercise is resistance exercises. These are exercises that use muscular strength to improve muscle mass and strengthen bone. Weight lifting would be an example of this kind of exercise. The NOF does not tell us how much exercise we should do to prevent osteoporosis, only that we do it. It is important that you and your doctor decide together how much exercise is right for you.

Calcium

When it comes to preventing osteoporosis, it is imperative that we get enough calcium and vitamin D. Calcium is needed by the body to form bone. Vitamin D is needed to absorb the calcium we take into our bodies. Taking adequate calcium has been shown to slow bone loss over time.⁶ Getting calcium from your diet is preferable because this type of calcium is more easily absorbed than pills. Dietary sources of calcium are listed below. Although vitamin D can be obtained from diet, about 5 to 10 minutes per day of sunlight is a reliable way to obtain vitamin D as going out into the sun triggers our body to make its own vitamin D.

Its important to note that our calcium requirements depend on factors such as age and lactation status:

Notice that the table notes elemental calcium. It is important to read labels carefully and realize many times the milligrams indicated on the front of a bottle of calcium note the milligrams of the whole calcium complex. It is important to look at the 'Drug Facts' label on the back of the bottle to get the real amount of elemental calcium. For example, a bottle of calcium carbonate may say, 'calcium carbonate 1500mg' on the front. However, if you look on the 'Drug Facts' label on the back, it will tell you that this formula only has 600mg of elemental calcium in it.

When taking a calcium supplement, it is also important to decide which kind to take. There are two main choices on the market: calcium carbonate and calcium citrate. Calcium carbonate should be taken with food as it needs the stomach acid produced when we eat to be absorbed. Calcium carbonate is usually not a good choice in the elderly. This is because they usually have decreased stomach acid. Calcium carbonate is also not a good choice if you are taking certain medications that decrease your stomach acid like Zantac, Pepcid or Prevacid. If this applies to you, you may consider calcium citrate. Calcium citrate is best if taken on an empty stomach. Finally, it is usually best to get a supplement that includes vitamin D as well. It is recommended that most adults over 50 years old need 400 to 600IU of vitamin D per day.

It is usually necessary to break up your calcium supplementation throughout the day. This is because out bodies can only absorb about 500-600mg at one time. For example, let's say your daily elemental calcium requirement is 1200mg of elemental calcium per day. Your calcium carbonate supplement contains 600mg of elemental calcium per tablet. You could take one tablet with breakfast and one tablet with lunch.

Treatment

The more negative the number on a T score, the greater the risk of fracture. Women with no risk factors should begin therapy if their T score is -2 or below; and women with risk factors should begin therapy if their T score is -1.5 or below. Remember, osteoporosis medications work best when you take the recommended daily amount of calcium that is right for you.

Conclusion

If you do not have osteoporosis, remember that prevention is key and the risk of osteoporosis should be reevaluated on an ongoing basis. If you have osteoporosis, treatment goals and the effects of medications should be reevaluated on an ongoing basis. One should schedule periodic exams, BMD testing and a reevaluation of risk factors with their doctor on a regular basis. Talk to you doctor about a followup schedule that is right for you.

Author: Christi Larson, Pharm. D.

REFERENCES

1. U.S. Department of Health and Human Services. Bone Health and osteoporosis: A Human Services, Office of the Surgeon General, 2004.
2. Optimal Calcium Intake: NIH Consensus Statement, 1994. Bethesda, MD. National Institutes of Health, 1994; 12(4):1-31.
3. National Osteoporosis Foundation. Physician's Guide to Prevention and Treatment of Osteoporosis. Washington, DC: National Osteoporosis Foundation, 2003.
4. Olszynski WP, Davison KS, Adachi JD, et al. Osteoporosis in men, epidemiology, diagnosis, prevention and treatment. Clin Ther. 2004;26(1):15-28.
5. Siris ES, Chen YT, Abbott TA, et al. Bone mineral density thresholds for pharmacological intervention to prevent fractures. Arch Intern Med,. 2004;164:1108-1112.
6. Optimal Calcijm intake: NIH Consensus statement, 1994. Bethesda , MD: National Insitutes of Health 1994; 12(4):1-31.
7. Osteoporosis Prevention, Diagnosis and Therapy. NIH Consensus Statement, 2000. Bethesda, MD: National INsitutes of Health, 2000;27-29:17(1):1-45