February 8, 2001
Bone problems are close to my heart. Our group from the Washington University School of Medicine in St. Louis was one among several groups that last year reported an increased frequency of osteopenia/osteoporosis in patients treated with potent antiretroviral therapy (see abstract 207, 2000). At this point, it is unclear if the problem is related to therapy or to HIV disease itself, although, in my opinion, the data suggest that it might be a combination of both. Patients with HIV have lower bone mineral density to start with, and then the treatment moves them over the top. Many posters and several presentations this year have been devoted to bone problems in HIV-infected patients.
This late breaker, and the one from S. Arpadi (Late Breaker 8) presented for the first time data on what might be going on in the bones of children. Adequate mineralization during infancy guarantees that an individual reaches an adequate bone mineral mass in early adulthood. Any factor that could affect bone mineralization in children could decrease peak bone mineral mass and predispose them to severe osteoporosis in adulthood. If the bone problems are important in adults, they are even more critical in children.
The data from this Italian group are fascinating. The researchers looked at 35 HAART-treated children, five naive HIV-positive children, and 314 healthy control children. They observed a decrease in bone mineral mass in children treated with HAART when compared to untreated children and to controls. There seems to be an association with lipodystrophy, but it was unclear how lipodystrophy was defined and they only had six children with it, which makes the sample size too small to make firm conclusions.
They also checked markers of bone formation and destruction and observed a state of high turnover (increased markers of bone formation and resorption), a finding similar to what our group has seen in adults and which we presented last fall in Toronto. Both studies are cross-sectional, and have the limitations inherent to this type of design, but they provide preliminary information that needs to be confirmed prospectively.
There is much to learn about the mechanism/s of this complication and how to prevent it. We desperately need longitudinal studies so that we can address the contribution of HIV versus the contribution of antiretroviral treatment.
This will continue to be a "hot" topic for the next conference -- hopefully with much more data about the potential mechanisms.