March 30, 2010
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Myles Helfand: We saw a number of studies at CROI that said much the same thing about bone disease and related complications.
Pablo Tebas: Yes. This is an area I am interested in because, many years ago, we observed that patients with HIV are more prone to having a low bone mineral density than the general population -- and that this problem is not only related to HIV, but also to the treatment of HIV.
There was a study of WIHS [Women's Interagency HIV Study], the women cohort, that didn't show that. Although that group, that cohort, is a little bit younger. So I was not very surprised that they didn't see an increase in risk factor. The other thing that I think we don't understand very well yet is osteopenia and osteoporosis. It's much more common in males with HIV than in women [with HIV]. So it's exactly the opposite of what we see in the general population, and we don't know why.
So that was one of the messages regarding bone: that patients with HIV are at increased risk of fracture.
Then there was a large presentation from Grace McComsey of a huge ACTG study, 5224, that looks at the effects of antiretroviral therapy on the bone. When you start antiretroviral therapy -- and this is completely independent of the regimen -- whenever you start antiretroviral therapy, the patients lose between 2% and 4% of their total bone mass.
If you start a regimen that includes tenofovir [TDF, Viread], you lose a little bit more than if you start a regimen that doesn't include tenofovir. And this happens quickly. And then, after 24 to 48 weeks, the bone mineral density tends to stabilize.
This is similar to what happens when you start steroids, although to a lesser degree: When you start steroids, you lose around 10% of your bone mass. When you start antiretroviral therapy, you lose around 3% or 4% of your bone mass.
This is another thing that patients with HIV should be aware of: that, because of their HIV and because of the treatment, they are at increased risk of osteopenia/osteoporosis. And I think, again, it's something that the clinician has to deal with. Basically, I think patients that are older than 50 that have HIV infection should have a DXA [dual energy X-ray absorptiometry] scan, and see where they stand. If they have indications for treatment [for bone loss], then they might need to be treated. And if they have normal bone mineral density, then we need to do the standard things that we suggest to everybody that is under medical care: Take enough calcium. Take enough vitamin D.
By the way, the frequency of low vitamin D levels is extremely high, and not only in HIV-positive patients. There were studies [presented at CROI] from the U.S., from Switzerland, from other countries, proving that the prevalence of low vitamin D is very high among patients with HIV. But it's also very high in the general population. So increasing vitamin D intake is something important that patients need to do for their bone health.
Because of these increased risks of osteopenia/osteoporosis with HIV, I think it's also important that people get diagnosed. I would do a DXA in everybody that is older than 50. If they're younger than 50, I don't think it's indicated, because the risk of fracture is relatively low. These patients are independent, and they don't have a risk of falling.
But as you age, and you become older than 50 -- particularly when you become older than 60 and around 70 -- is when you start having frailty. And your risk of falling and then fracturing something is higher. And that is associated, ultimately, with a lot of morbidity and mortality.
So I think the message is that osteopenia is common, and osteoporosis; that we have to deal with it; and that, as in the general population, the presence of low bone mineral density, measured by DXA, is associated with an increased risk of fractures.
Myles Helfand: So, just to clarify: You wouldn't necessarily suggest any kind of screening intervention unless a patient is over the age of 50? If they are younger, is it more that they should just be taking preventive measures at that point? Actively doing something to ensure that they don't develop problems when they're older?
Pablo Tebas: Yes. That's my -- it's not only my; it's the National Osteoporosis Foundation's -- recommendation. So if you are older than 50, you should have a DXA, if you have a risk factor for osteopenia or osteoporosis. And I think HIV infection, by itself, is a risk factor for osteopenia/osteoporosis. So I would say anybody with HIV, men or women, older than 50 should have a DXA. Younger than 50, I think general health measures to improve bone health are the way to go.
If you have HIV and you have had a fracture before, independently of your age, you should have a DXA. So, if you fell down the stairs and you fractured your wrist and you were 40, and you have HIV and you are taking medicine, you should have a DXA. Because you might have osteopenia/osteoporosis. Having just the accident doesn't have anything to do with your bone health, but there is no way to know, except doing a DXA.
But in general, my recommendation will be, for the general HIV-positive population, I would do a DXA in everybody that is older than 50. That's the recommendation for the general population, if you have a risk factor for the disease. And, as I said, I think HIV is a risk factor. It's not included in the list of the National Osteoporosis Foundation, because it probably was an oversight. But definitely patients with HIV are at increased risk of osteopenia/osteoporosis. And now we know, thanks to some of the presentations at CROI, that they are also at increased risk of fractures.
No comments have been made.
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