DXA and bisphosphonate use in young, healthy patients

Editor’s note: This blog entry is in response to the following comment made to one of Dr. Kleerekoper’s previous blog entries: "This is really intriguing. I'm a 30-year-old female who was diagnosed with osteopenia at 26. My hip and spine DXA readings were both a –1.7. I'm on 100,000 IU of vitamin D each week plus risedronate. I suddenly feel as though my results have not been interpreted properly, even though I'm told I am working with some of the best in the field." [From: Jenda]

Jenda,

I can think of no good reason why a DXA study should be ordered in a healthy 30-year-old woman or man. Some patients request it at that age because of interest or a recent diagnosis in a family member. This is not a good reason to do an unnecessary test but it is appropriate to use the opportunity to educate the patient about maintaining optimum bone health with appropriate attention to diet and lifestyle.

A 29-year-old dentist requested such a study because she wanted to have a baseline for when she becomes menopausal. I asked her how much of her current dental office equipment would be unchanged 20 years hence. The same is of course true for most of the medical tests and procedures in use today.

If a doctor suggests a DXA in a healthy young woman it’s time to seek your medical advice elsewhere. It is also important to understand that no matter what age the first DXA is done, no comment can or should be made about bone loss. Even a person with a T-score of –2.2 might never have had a higher bone density. You simply cannot make a dynamic statement on the basis of a single time point measurement.

In the absence of any other information about you (please don’t send any because I will not be able to answer) I have no idea whether your –1.7 (which is perfectly normal for a 30-year-old woman) is the best you have ever had or whether you once had a better bone density.

There are a number of genetic diseases that affect the skeleton and there are also a number of acquired conditions and some medications that are potentially harmful to the skeleton. Acknowledging my bias, in those circumstances the patient should be referred to a specialist for a complete evaluation before the DXA is done.

I cannot resist the opportunity to address the other items in your comment.

100,000 IU of vitamin D each week is a very large amount and infrequently needed unless the patient has some problems with absorption. Even then 100,000 IU a week is hardly ever needed. Of course, when possible, the cause of the malabsorption needs correction.

Caution should be used when recommending a bisphosphonate to a woman with child-bearing potential, even in the face of an abnormal DXA. I know of no data to suggest that bisphosphonates might be harmful to a developing fetus, but I also have no data that they are not harmful. Bisphosphonates have a long half life in the skeleton and stopping them the day the first pregnancy test is positive might not be soon enough. Why take the risk unless the bone disease is severe and symptomatic (eg, children with some types of osteogenesis imperfecta)?

Disclosure: Medical advice provided to patients in these blogs is given in general terms and should always be discussed with the treating physician. EndocrineToday.com bloggers are not in a position to provide patient-specific advice because they have not had the opportunity to obtain a detailed medical history or conduct a physical examination, which are essential to patient care.