title: Differentiating the Influences of Aging and Adiposity on Brain Weights, Levels of Serum and Brain Cytokines, Gastrointestinal Hormones, and Amyloid Precursor Protein.
abstract: Aging and obesity exert important effects on disease. Differentiating these effects is difficult, however, because weight gain often accompanies aging. Here, we used a nested design of aged, calorically restricted, and refed rats to measure changes in brain and blood levels of cytokines and gastrointestinal hormones, brain amyloid precursor protein levels, and brain and body weights. By comparing groups and using path analysis, we found divergent influences of chronological aging versus body weight, our main findings being (i) changes in whole brain weight and serum macrophage colony-stimulating factor levels correlated better with body weight than with chronological aging, (ii) a decrease in brain cytokines and brain plasminogen activator inhibitor levels correlated better with chronological aging than with body weight, (iii) serum erythropoietin levels were influenced by both body weight and aging, (iv) serum plasminogen activator inhibitor, serum cytokines, and brain tumor necrosis factor were not influenced by aging or body weight, and (v) brain amyloid precursor protein more closely related to body weight and serum levels of gastrointestinal hormones than to brain weight, chronological aging, or cytokines. These findings show that although aging and body weight interact, their influences are distinct not only among various cytokines and hormones but also between the central nervous system and the peripheral tissue compartments.
authors.affiliation: Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington. Division of Gerontology and Geriatric Medicine, Department of Internal Medicine, University of Washington School of Medicine, Seattle. wabanks1@uw.edu.
authors.forename: William A
authors.initials: WA
authors.lastname: Banks
authors.affiliation: Primary and Specialty Care Medicine, Department of Veterans Affairs Puget Sound Health Care System, Seattle, Washington.
authors.forename: Christine K
authors.initials: CK
authors.lastname: Abrass
authors.affiliation: Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington.
authors.forename: Kim M
authors.initials: KM
authors.lastname: Hansen
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000375:Aging / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000818:Animals; D001835:Body Weight / Q000502:physiology*; D001921:Brain / Q000378:metabolism / Q000473:pathology; D004921:Erythropoietin / Q000097:blood; D005768:Gastrointestinal Hormones / Q000097:blood; D020738:Leptin / Q000378:metabolism*; D016173:Macrophage Colony-Stimulating Factor / Q000097:blood; D008297:Male; D009765:Obesity / Q000378:metabolism; D009929:Organ Size; D015849:Plasminogen Inactivators / Q000378:metabolism; D051381:Rats; D013223:Statistics as Topic; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016564:Amyloid beta-Protein Precursor; D005768:Gastrointestinal Hormones; D020738:Leptin; D015849:Plasminogen Inactivators; D014409:Tumor Necrosis Factor-alpha; D004921:Erythropoietin; D016173:Macrophage Colony-Stimulating Factor
keywords: Aging; Amyloid precursor protein.; Cytokines; Leptin; Obesity