Impact of Testosterone Levels on Bone Mineral Density May Be More Pronounced in HIV-Infected Patients
An Interview With Ranjani Raghunathan, M.D.
October 27, 2008
There's nothing like hearing the results of studies directly from those who actually conducted the research. In this interview, you'll meet one of these impressive HIV researchers and read her explanation of the study she presented at ICAAC/IDSA 2008.
Ranjani Raghunathan: My name is Ranjani Raghunathan. I was recently a fellow at Loyola University Chicago Stritch School of Medicine. I did this study to answer a question that I couldn't find the answer to in the literature: Among HIV patients, would having a lower testosterone level correlate with a lower bone density?1
What's been shown so far is that among non-HIV patients, there seems to be a correlation between testosterone and bone density. But this hasn't clearly been shown among patients with HIV using a control group, a non-HIV-infected group.
I controlled for as much as one can in a retrospective study, looking at about 80 HIV patients and about 154 non-HIV patients. I controlled for the factors that cause osteoporosis, such as age, race and smoking -- things that generally would be associated with osteoporosis in both groups.
Bonnie Goldman: Could you walk us through the factors you compared?
Ranjani Raghunathan: I looked at hypertension, diabetes, hepatitis, previous drug use and if they've smoked ever; these are all the factors that one would associate with osteoporosis. Whether they've used prednisone [Prednisone Intensol, Sterapred] in the past -- again, another factor. Activity level, because one would expect those with a low activity level to have a lower [bone density].
Conference Attendee: Did you measure vitamin D?
Ranjani Raghunathan: No. It's not a prospective study; this is a retrospective study. One of the things [I would have liked to have looked at] would be PTH [parathyroid hormone], vitamin D and bone turnover markers.
Conference Attendee: You mention osteopenia levels, but you haven't got a measure of vitamin D. So how [can we know how much of the low bone density is caused by low] testosterone, and how much is attributable to something that you haven't looked at, such as bone turnover markers?
Ranjani Raghunathan: I think bone turnover markers would have been great. I think one should definitely look at that prospectively. But given that this was a retrospective study, I just looked at [different] factors. Calcium [for instance]: These are certain biochemical markers that one would see if there's a difference between the two groups.
What I found by comparing the two groups at the femoral neck, lumbar spine and hip, is that there seems to be a protective factor to having a normal or greater testosterone level with regard to bone density. Also, having a lower testosterone level seems to correlate with lower T scores, particularly in the lumbar spine.
Again, there are several limiting factors in a retrospective study. That's why I wanted to bring this up: so that, in the future, we can look at how the interaction between HIV and testosterone affects bone densities.
Bonnie Goldman: What have been the most frequent questions asked about this poster by other researchers who have come by?
Ranjani Raghunathan: What they wanted to know is, in the HIV group, would the duration of HIV, or the duration of being on antiretrovirals, affect bone density changes? It's hard to tell because, again, this is a retrospective study; you need to look at the study more prospectively. But what we need to find out first of all is whether there is a correlation between the two. It seems like there is. We need to use this as a stepping board to look at further studies to see if there is true interaction between the two.
Bonnie Goldman: Thank you so much.
This transcript has been edited for clarity.
This article was provided by TheBodyPRO.com. It is a part of the publication The 48th Annual ICAAC/IDSA 46th Annual Meeting.