Finally, IH associates with sympathetic activation in both animal models and humans [26,27], as witnessed by results obtained in healthy awake adults undergoing intravenous GTT under control and 5 h IH conditions aimed at simulating moderate OSA, who also displayed decreased insulin sensitivity and glucose effectiveness despite unchanged pancreatic insulin secretion and serum cortisol levels [28]. Here, INS is linked to obstructive sleep apnea syndrome.