October 25, 2010
Both HIV infection and exposure to medicines, including anti-HIV medicines, can affect mitochondria, the parts of a cell that produce energy. Impaired mitochondria produce less energy and so cells do not function properly. At the level of tissues or organs this can lead to organ dysfunction and perhaps even affect the immune system.
Researchers at the University of Miami and elsewhere in the U.S. collaborated on a pilot study to assess the impact of antioxidants and nutrients used by the body to make antioxidants on the functioning of mitochondria. Their preliminary findings suggest that a mix of nutrients is helpful in improving the functioning of mitochondria, at least in the short term. There were also hints of favourable changes to the immune system.
Researchers enrolled 25 HIV-positive adults who were on stable ART regimens and whose viral loads were less than 50 copies/ml. They were randomly assigned to one of the following interventions for eight consecutive weeks:
To test for damage to mitochondria, participants' blood was analysed using an assay called Oxphos activity from the MitoSciences Corporation in Eugene, Oregon.
The average profile of participants at the start of the study was as follows:
Over the eight weeks of this pilot study there were trends that approached but did not achieve statistical significance with the following metrics:
Bear in mind that this was a small study and it can take several months for new CD4+ cells to be produced and complete their maturation cycle before becoming fully functional. So, any increased cell numbers seen before this time likely arise from cells that were either redistributed from lymph nodes and tissues (where 98% of the body's lymphocytes are found) into blood or from cells that were rescued from death by antioxidants. Had this study enrolled many more participants and continued for up to two years, they might have found statistically significant changes.
Statistically significant differences in mitochondria function were seen between the two interventions, with improvements in the group that received nutrients. And a trend toward decreased insulin resistance was seen in the group that received nutrients. This is not surprising because in animal experiments alpha-lipoic acid has been found to decrease insulin resistance. HIV infection appears to increase the risk for diabetes by increasing inflammation, and antioxidants such as alpha-lipoic acid have the potential to improve insulin resistance.
The present pilot study shows some encouraging trends that need to be better understood in further controlled clinical trials. One such trial, the Maintain study (CTN 238), is underway across Canada. This study explores the impact of a more complex mix of antioxidants and micronutrients in HIV-positive people. Click here for more information about the Maintain study.