Bone Disease and HIV/AIDS: More Common Than You Think -- This Month in HIV
An Interview With Todd Brown, M.D., Ph.D., and Ben Young, M.D., Ph.D.
Bonnie Goldman: Let's go back to the basics about bone health. Dr. Young, you said that you're looking at all the patients in your practice. How can someone find out if he or she has healthy bones? You mentioned DXA scans. Are there any symptoms that someone might have? Is there something else that would tell someone that he or she might have bone disease?
Ben Young: The key part here is that for the most part, bones don't cause symptoms until they fracture. Probably, the most important thing to stress to patients is that you largely don't have symptoms, and could have bone disease.
In fact, there's a lot of interest in trying to determine which specific risk factors may place one person or another at greater risk of having bone disease. Obviously, there's a lot of research interest in trying to sort out the specific mechanisms of this.
The large surveys suggest that this is a common enough problem that in a way I don't really care what's the specific matrix of risk factors that puts one individual at risk or not; it's common enough in our practice that we see this with quite a bit of frequency.
Indeed, it was with a collaboration with Dr. Brown in a CDC-sponsored study called SUN that we really first became aware of the specific problems in our patients.3 Namely, in our practice, about 50 percent of our patients have bone disease. About 10 percent have osteoporosis. Virtually all of these patients were living their lives just fine before we did the specific testing to look for it.
So, to your point: There are methodologies to measure the calcium content and the density of the bones. The best and most quantitative way to do that is with these DXA scans.
In fact, that's what we are now embarking on doing for all the patients in our practice. As we expand the number of patients we have screened, from the initial 100 that were in the clinical study to in the neighborhood of 400 or 500 individuals, the numbers remain just that: About 50 percent of our patients have abnormal bone mineral density. And it's quite a bit of a concern.
The problem is that one really needs to do that test to have the best measure of it. There are probably some alternative strategies that are worth mentioning.
For one, many people do get X-rays, for one reason or another. The information in those X-rays can often reveal abnormally low bone mineral density. But one has to be mindful to ask the radiologist. We have occasionally picked up abnormal bone density on chest X-rays that were done not looking for bone density, but rather for pneumonia.
A fracture that is unexplained from a not-so-traumatic event should not just be written off as just an unfortunate fall, or a weird step off the curb that broke your ankle. One should ask the question: Is that a patient who might actually have abnormal bone density?
Bonnie Goldman: Are DXA scans generally covered by insurance and Medicaid?
Ben Young: To my surprise, they are actually covered by most insurance companies. I should add that patients who have other significant risk factors (for example, patients who have been on long-term corticosteroid therapies, patients who have abnormally low testosterone levels or patients who have had abnormal fractures in the past) have access to DXA scans, both by insurance companies and by Medicaid.
The Medicaid question and HIV is a problematic one, because it's not well covered, if at all. Medicaid is variable. It depends a little bit on state funding and such, but it is usually not covered. There are people trying to improve that. But if one has third party insurance, it's pretty easy to get a DXA scan. The doctor just needs to know what to ask for.
Bonnie Goldman: Would you say that everyone with HIV should get a baseline DXA?
Ben Young: This will be controversial, but in our practice, that's our standard. There are no U.S.-based guidelines for this.
"From a knowledge gained and a preventive medicine perspective, the information I get from doing $100 test to look at bone health, is probably more valuable than doing a fourth or fifth viral load test in a patient who is otherwise doing well."
-- Ben Young, M.D., Ph.D.
I summarize it this way: One out of every two patients in my practice probably has abnormal bone density. The cost of doing a scan is roughly $100. It's about half the price of doing a viral load test. From a knowledge gained and a preventive medicine perspective, the information I get from doing a $100 test to look at bone health is probably more valuable than doing a fourth or fifth viral load test in a patient who is otherwise doing well.
Todd Brown: I differ a little bit here. I think that a bone density test is a decent way to assess fracture risk. But the problem that you get into is that people who are younger than 50 really don't fracture all that often. If we were talking about universal screening of HIV-infected patients, I would suggest screening people over the age of 50.
Even if someone has low bone density by DXA and may be at increased risk of having a fracture compared to someone of a similar age who has normal bone density, the chances that he or she is going to have a fracture are just so low, because young people generally don't have fragility fractures.
Ben Young: This is something that is a nice point of debate, Todd. I'll differ with you again a little bit, to make just a couple of points.
Number one is that the largest study regarding this comes from the Massachusetts Study Group, comparing HIV negatives to HIV positives, in which the fracture rate for sub-40-year-olds who are HIV positive approximates that of an HIV-negative 50-year-old. You were an author on this, I believe.4 That analysis suggests that the fracture frequency of HIV positives who are young approximates the fracture frequency for HIV negatives aged greater than 50.
Moreover, to me, the biggest concern is that young people are still in a period where they can improve their bone health with improvements in modifiable risk factors, including calcium supplementation and normalizing vitamin D levels and such.
So there's an opportunity -- if we identify those people earlier. I'd hate to miss the opportunity to improve their bone health before they reach their bone density maximum at age 40 or so.
From a cost benefit analysis, while I think the fracture absolute frequency is, yes, relatively low, there's still an opportunity to intervene with a preventive medicine strategy.
Todd Brown: The counterargument to that is that a lot of the strategies that can be taken to improve bone health should be undertaken in everyone. This means maintaining adequate vitamin D intake and adequate calcium intake, refraining from smoking, refraining from excessive alcohol use; all those things you want to be doing in everyone.
The concern that I have in screening people who are at low fracture risk is that they might be inappropriately put on medications that have long-term side effects for their bones, and they may not actually benefit from them.
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This article was provided by TheBody.com. It is a part of the publication This Month in HIV.
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