NPY and obesity disorder: In addition, whether other hypothalamic neuropeptides with known effects in both feeding control and the modulation of nociceptive processing, such as orexin, oxytocin (OT), neuropeptide Y (NPY), and pituitary adenylate cyclase activating protein (PACAP) (53), are also important players in the association between obesity and headache remains to be elucidated.