title: Age and its association with low insulin and high amyloid-β peptides in blood.
abstract: Age is the major risk factor for developing Alzheimer's disease (AD), and modifying age-related factors may help to delay the onset of the disease. The goal of this study was to investigate the relationship between age and the metabolic factors related to the risk of developing AD. The concentrations of insulin, amylin, and amyloid-β peptide (Aβ) in plasma were measured. We further measured the activity of serum Aβ degradation by using fluorescein- and biotin-labeled Aβ40. Apolipoprotein E4 allele (ApoE4) and cognitive impairment were characterized. Subjects were divided into three age groups: 60-70, 70-80, and ≥80 years old. We found that the older the subjects, the lower the concentration of insulin (p = 0.001) and the higher the concentration of Aβ1-40 (p = 0.004) in plasma. However, age was not associated with the concentration of another pancreatic peptide, amylin, and only marginally with Aβ1-42. These relationships remained in the absence of diabetes, cardiovascular disease, and stroke, and regardless of the presence of ApoE4 and cognitive impairment. Both age and ApoE4 were inversely associated with, while insulin was positively associated with, the activities of Aβ degradation in serum. Our study suggested that low concentration of insulin and high concentration of Aβ40 are aging factors related to the risk of AD.
authors.affiliation: Departments of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA.|Department of Neurology, The First People's Hospital of Chang Zhou, China.
authors.forename: Huajie
authors.initials: H
authors.lastname: Li
authors.affiliation: Departments of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Haihao
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Departments of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Max
authors.initials: M
authors.lastname: Wallack
authors.affiliation: Department of Public Health and Family Medicine, Tufts University, Boston, MA, USA.
authors.forename: Mkaya
authors.initials: M
authors.lastname: Mwamburi
authors.affiliation: Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA.
authors.forename: Samer O
authors.initials: SO
authors.lastname: Abdul-Hay
authors.affiliation: Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA.
authors.forename: Malcolm A
authors.initials: MA
authors.lastname: Leissring
authors.affiliation: Departments of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA.|Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Wei Qiao
authors.initials: WQ
authors.lastname: Qiu
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000544:Alzheimer Disease / Q000097:blood*; D016229:Amyloid beta-Peptides / Q000097:blood*; D053327:Apolipoprotein E4 / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D003072:Cognition Disorders / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D058228:Islet Amyloid Polypeptide / Q000097:blood*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010446:Peptide Fragments / Q000097:blood*
chemical_list: D016229:Amyloid beta-Peptides; D053327:Apolipoprotein E4; D015415:Biomarkers; D007328:Insulin; D058228:Islet Amyloid Polypeptide; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40)
keywords: Alzheimer’s disease; ApoE4; Aβ; Aβ degradation; age; insulin