LEP and Alzheimer disease: This tendency towards increased peripheral fat in 2–3 mo 3xTg-AD mice was not reflected in changes in circulating plasma levels of total free fatty acids (p = 0.9386, unpaired t-test, Fig S1a) or triglycerides (p = 0.6880, unpaired t-test, Fig S1b); however, the concentration of leptin, a key metabolic hormone that correlates with adiposity and is itself secreted by adipose tissue, was significantly elevated in 3xTg-AD plasma (p = 0.0301, unpaired t-test, Fig S1c).