GHRL and Alzheimer disease: Nonetheless, considering the fact that the area under the curve value of ghrelin was increased by glucose loading only in male patients with AD, not in female patients (Theodoropoulou et al., 2012), and the higher basal ghrelin levels in female healthy and opposite-sex twin pair subjects than men (Makovey et al., 2007; Song et al., 2017), difference in effects of ghrelin for AD-related metabolic syndrome according to gender should be examined in the future.