Use of Muscle Spectroscopy to Evaluate Mitochondrial Dysfunction in HIV-Infected Patients

NRTI-related mitochondrial toxicity has been implicated in some fatal cases of lactic acidosis and liver failure. In addition, some investigators believe NRTI-related mitochondrial toxicity to be the culprit in the development of peripheral neuropathy and lipodystrophy in HIV-infected patients. There is a need for a sensitive, reproducible, and noninvasive marker of mitochondrial dysfunction. To date, the only available noninvasive marker is lactate, but lactate testing is insensitive and the significance and reproducibility of lactate levels in the HIV-infected population are questionable. Spectroscopy promises to be a very useful alternative for the evaluation of the in vivo effect of NRTIs on mitochondrial function. Prior to the screening visit, HIV-infected participants must fast for at least 12 hours and refrain from exercise for at least 24 hours. At the screening visit, all participants have blood drawn for lactate measurements and tests for hepatitis B and C. HIV-uninfected participants have an HIV test. Women who are able to become pregnant have a pregnancy test. Prior to the entry visit, HIV-infected participants must fast for 12 hours and refrain from exercise for 3 days. At the entry visit, all participants have blood drawn for lactate measurements and women have repeat pregnancy tests. Participants have an MRS scan, which takes approximately 60-80 minutes.