Differential effects of blood insulin and HbA1c on cerebral amyloid burden and neurodegeneration in nondiabetic cognitively normal older adults

作者：Byun Min Soo; Kim Hyun Jung; Yi Dahyun; Choi Hyo Jung; Baek Hyewon; Lee Jun Ho; Choe Young Min; Sohn Bo Kyung; Lee Jun Young; Lee Younghwa; Ko Hyunwoong; Kim Yu Kyeong; Lee Yun Sang; Sohn Chul Ho; Woo Jong Inn; Lee Dong Young

来源：Neurobiology of Aging, 2017, 59: 15-21.

DOI：10.1016/j.neurobiolaging.2017.07.004

• Insulin
• Glycated hemoglobin
• Preclinical Alzheimer's disease
• Cerebral amyloid burden
• Neurodegeneration

We tested the hypothesis that lower insulin or higher glycated hemoglobin (HbA1c) levels in blood are associated with increased cerebral beta amyloid (A beta) deposition and neurodegeneration in nondiabetic cognitively normal (CN) older adults. A total of 205 nondiabetic CN older adults underwent comprehensive clinical assessment, [C-11] Pittsburgh compound B (PiB)-positron emission tomography (PET), [F-18] fluorodeoxyglucose-PET, magnetic resonance imaging, and blood sampling for fasting insulin and HbA1c measurement. Lower blood insulin was significantly associated with increased A beta positivity rates and decreased cerebral glucose metabolism in the AD-signature region. In contrast, higher HbA1c levels were not associated with A beta positivity rates but were significantly associated with higher rates of having neurodegeneration in the AD-signature regions. Our results suggest different roles of insulin and HbA1c in AD pathogenesis, in that decreased blood insulin below optimal levels may contribute to increasing cerebral A beta deposition and neurodegeneration whereas impaired glycemic control may aggravate neurodegeneration through a nonamyloid mechanism in nondiabetic CN older adults.

• 出版日期2017-11