Leptin enhances synaptic plasticity in the hippocampus, promotes β-amyloid clearance, and improves memory performance in animal models of aging and AD.48 In the Framingham Heart Study, higher plasma leptin levels were associated with a lower risk of incident dementia and with favorable brain health indices.49 Adiponectin, on the other hand, exerts insulin-sensitizing, anti-inflammatory, and antioxidant effects in peripheral tissues, functions that may also provide protection against neurodegenerative processes such as AD.50 Here, INS is linked to Alzheimer disease.