Studies link HIV drugs and bone density problems
Studies link HIV drugs and bone density problems
Research examining HIV in children and women
Several recent studies add to the evidence that HIV infection and possibly highly active antiretroviral treatment (HAART) increase risks or at least are associated with the loss of bone mass among women and children.
The research suggests that clinicians should watch for bone density loss and osteoporosis risk factors among their HIV-infected patients and evaluate bone mass in those who are at risk.
"If you were going to think how this affects your practice, then limit screening to those women who are perimenopausal or post-menopausal and who are low weight and smoke," says Michael T. Yin, MD, a clinical fellow in infectious disease at Columbia University in New York City.
Yin was the principal investigator of a study that found that lumbar spine osteoporosis is considerably higher in HIV-infected Hispanic and African-American, post-menopausal women than among racially comparable healthy populations.
The study concluded that diagnosis and treatment of osteoporosis should play a more prominent role in the long-term management of the female HIV population as this population ages.1
"There is some suggestion that bone deterioration doesn’t seem to really take off until around the menopausal period, even for HIV-positive patients," he says. "And there are several hypotheses for this, including that there is an interaction between estrogen deficiency and HIV infection or treatment."
Another theory is that this population of HIV-infected women is different from the general population because they may not have reached their peak bone mass since they were ill at an early age, Yin says.
"It’s been suggested in both epidemiological studies and in some in-vitro experiments that protease inhibitors can affect the bone mass. The best type of study would start off with people infected pre-menopause and before they got HIV treatment and just follow them for many years," he explains.
Boston investigators also have been examining the association between low bone-mineral density and the use of antiretroviral medications in HIV-infected women.
"We found that 34% of the 44 Caucasian women with HIV had signs of low bone-mineral density, and all but one were osteopenic," says Denise Jacobson, PhD, MPH, assistant professor at the Tufts University School of Medicine in Boston.
The only severe case was a woman with osteoporosis among the group that had a mean age of 39, she says.
"By comparison, I haven’t been able to find a percentage of women in this age group in the normal population who would have osteopenia," Jacobson says. "If you use a different bone scan for women ages 50 to 59, you find that 37% have osteopenia or osteoporosis; but that’s not the same scan, and you can’t infer that women with HIV are seeing this disease early on."
The Boston study also examined the change in bone marrow density over time and found that 42 of the 44 women had changes in their two-year follow-ups, she says. "The change over time was not associated with age or being African-American vs. Caucasian or Hispanic, and the change was not related to smoking."
"We didn’t find any association with their viral load or with overall HAART use; but we’re exploring associations with different types of HAART, and the numbers are small," Jacobson adds.
There was a significant positive correlation between a change in the bone-mineral density over the two-year period and a change in lean body mass over the same interval.2
It’s still premature to recommend that clinicians screen all female HIV-infected patients for bone scans, she says.
"As an epidemiologist, I could say we need to develop predictors of low-mineral bone density that would indicate when it’s appropriate to scan a patient," Jacobson adds. "Predictors could be other risk factors, lifestyle factors, and clinical risk factors."
In another study of HIV-infected children, Texas investigators found that 75% of the children studied had some decreased bone mass when compared to a healthy population of children. Of 26 children who completed the study, 18 (69%) were taking protease inhibitors; most exceeded or met the recommended daily amount of calcium, and 17 children had osteopenia, and six had osteoporosis.3
Unanswered question regarding children
The study could not explain why HIV-infected children have decreased bone density, says Heidi Schwarzwald, MD, MPH, assistant professor at the Baylor College of Medicine in the department of pediatrics at the Baylor International Pediatric AIDS Initiative in Houston.
The study’s findings suggest that HIV-infected children may be at risk of not developing adequate bone density in their youth, which could result in major problems when they are adults, she says.
"Most of these kids are not at risk for any fractures," Schwarzwald says. "But it’s a long-term risk, and they’re at higher risk later on in life and probably will have fractures at age 40."
More research into how HIV and HIV medications impact bone density among children is needed, she notes.
"We saw increasing numbers of adult studies and were interested in seeing bone density data in children," Schwarzwald says. "Now that we’re seeing bone density decreases in kids, we need to find a solution."
References
1. Yin MT, Dobkin JF, Brudney KF, et al. Osteoporosis in post-menopausal HIV-positive women. Presented at the 10th Conference on Retroviruses and Opportunistic Infections. Boston; February 2003. Poster 766.
2. Jacobson D, Knox T, Shevitz A, et al. Low bone mineral density in HIV-infected women. Presented at the 10th Conference on Retroviruses and Opportunistic Infections. Boston; February 2003. Abstract 102.
3. Schwarzwald H, Ellis KJ, Evans DL, et al. Effect of HAART on bone density in HIV-infected children. Presented at the 10th Conference on Retroviruses and Opportunistic Infections. Boston; February 2003. Poster 778.
Several recent studies add to the evidence that HIV infection and possibly highly active antiretroviral treatment (HAART) increase risks or at least are associated with the loss of bone mass among women and children.Subscribe Now for Access
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