Hypopituitarism and HIV-infection: a new comorbidity in the HAART era?

Several comorbidities are associatedwith the HIV infection and may involvealso the endocrine-metabolic system. Consistently,the recent development of the therapeuticregimen highly active antiretroviraltherapy (HAART) ruled out a significant improvementboth in the prognosis and life expectancyof HIV-infected patients, but disclosedalso new serious drug-related toxicity.Of these, the lipodystrophy syndrome isthe most frequent, occurring in up to 83% ofHIV-infected patients under HAART. The HIVrelatedlipodystrophy is associated with alterationsin GH dynamics, affecting bothbasal and stimulated GH secretion. This GHIGF-I secretive pattern resembles that of severeGH deficiency in adulthood due to pituitarydiseases, but without leading to IGF-Iserum levels below the normal range. The impairmentof pituitary GH secretion has beenascribed to the hormonal and metabolic inhibitoryeffect due to adipose tissue redistributionin HIV-infected males, since in thesepatients pituitary GH secretion appeared tobe inversely related to visceral adipose tissueaccumulation and waist to-hip-ratio. However,whether these patients suffer from a true GHdeficiency due to an intrinsic pituitary failureor display only a functional reduction of GHsecretion due to visceral adiposity remainsstill a matter of debate, especially in HIV-infectedfemales