SREBF1 and Insulin resistance: In vitro studies have evidenced an inhibitory effect of PIs on GLUT4, which causes insulin resistance in HIV-positive individuals [25,26] and affects the transcription factor SREBP-1 (steroid regulatory element binding protein-1c), which in turn affects the glucose metabolism by producing imperfect peroxisome proliferator- activated gamma receptor (PPAR-y), which plays an important role in the metabolism of glucose and lipids [27].