HCRT and Alzheimer disease: Among the others, insulin resistance links metabolic issues to cognitive impairment in AD [2]; reduced levels of orexin, a neuropeptide that regulates wakefulness, is associated with cognitive deficits and may accelerate neurodegeneration [3,4]; and somatostatin and CRH influence cognitive function and are altered in AD [5,6], with CRH being linked to amyloid-beta accumulation.