Different hypothalamic neuropeptides involved in metabolic control are also reported to be altered and although glycemia and circulating insulin levels are usually unaffected, insulin resistance is a common feature of AD with reduced signaling at central insulin and IGF-1 receptors (Steen et al., 2005; Talbot et al., 2012), contributing to deficits in neural function, synaptic plasticity, and cellular integrity. Here, INS is linked to Alzheimer disease.