The Australian study that uncovered a link between high levels of lactic acid and bone damage in PHAs (see previous story) is perhaps not surprising. Last year, researchers in Spain found that people with hepatitis C virus infection (who were HIV negative) who used a combination of the anti-hepatitis-C nuke ribavirin with interferon-alpha had an increased risk of developing thinning bones compared to other people with hepatitis C who used interferon only.
The common link between the HIV positive and HIV negative groups of people is the use of a group of drugs called nukes. These drugs damage the energy-producing parts of a cell, called mitochondria, and appear to cause the liver to produce higher-than-normal levels of lactic acid, or lactate.
Although both the Australian and Spanish results need to be confirmed by other researchers, it is important to note that there are other factors associated with bone loss. Some of these factors likely play a role in the bone health of PHAs. These factors can include the following:
Researchers are not sure about the best way to protect the bones of HAART users. A first step might be to develop a regimen of nutrients that nourish and protect mitochondria:
Another step may be to take supplements of bone-building nutrients such as calcium and vitamin D3. To help maintain bone health, the dose of calcium recommended by the American Institute of Medicine for "older adults" is between 1,000 to 1,500 mg per day. The best dose of vitamin D3 for adults with osteoporosis is not clear but is probably somewhere between 400 to 1,000 international units per day. Readers should note that there appear to be factors other than nuke-related bone damage which need further study.
Even though the Australian researchers mentioned in the previous report on lactic acidosis and bones found little or no connection between thinning bones and protease inhibitors (PIs) or non-nukes, other researchers may have found such a link. A research team in the U.S. has found that in lab experiments PIs and non-nukes impair the liver's ability to convert vitamin D to its useful or "activated" form, vitamin D3. Without sufficient amounts of active vitamin D, the body may be unable to absorb and retain enough calcium to build and maintain strong bones.
PIs may also interfere with the growth and development of cells in the bone marrow that eventually turn into bone-building cells.
It is also possible that HAART may upset certain chemical signals, such as TNF, used by both the immune system and bone cells. This can have the effect of unnecessarily prolonging the life of specialized cells whose function is to tear down bones. Further study of the drugs that make up HAART and their impact on bone health needs to be done.
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Copyright © 2001 - TreatmentUpdate. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the Editor, The Canadian AIDS Treatment Information Exchange, 555 Richmond St. West, Suite 505, Box 1104, Toronto, ON, M5V 3B1 • Phone: 416-203-7122 • Toll Free: 1-800-263-1638 • Fax: 416-203-8284 http://www.catie.ca.
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