Pathophysiology of GHRH-growth hormone-IGF1 axis in HIV/AIDS.

Aberrations in GHRH-GH -IGF-I axis are common in the complex of HIV, HAART and AIDS. There are 2 distinct mechanisms at play in HIV and AIDS. One is primarly associated with development of lipodystrophy and results in complications such as chronic inflammation, insulin resistance, lipid and metabolic abnormalities. HIV lipodystrophy is found especially in those on highly active anti-retroviral therapy (HAART). The various processes involved in lipodystrophy result in the suppression of pituitary GH production. The mechanism of low GH levels relates to increased somatostatin tone, decreased Ghrelin, increased free fatty acids (FFA) and insulin resistance. On the other hand in AIDS wasting syndrome; elevated GH and low IGF-1 levels are seen suggesting GH resistance. The GHRH analog-Tesamorelin is the only treatment option, which is FDA approved for use in reduction of excess abdominal fat in patients with HIV-associated lipodystrophy. Although long-term clinical trials and experience is needed to further study the benefits and risks of Tesamorelin.