title: The metabolic syndrome, IGF-1, and insulin action.
abstract: Recent studies have shown that insulin and insulin-like growth factor (IGF)-1 signaling are involved in the control of ageing and longevity in model organisms. Based on these studies, genes involved in the insulin/IGF-1 signaling pathway are believed to play a role in longevity throughout evolution and could also be important in determining human longevity. However, human studies have yielded conflicting and controversial results. In human, defects in insulin receptor signaling cause insulin resistance and diabetes, and IGF-1 deficiency is associated with an increased risk of cardiovascular disease and atherosclerosis. Interestingly, insulin sensitivity normally decreases during aging; however, centenarians were reported to maintain greatly increased insulin sensitivity and had a lower prevalence of the metabolic syndrome as compared to younger subjects. Additionally, a longitudinal study revealed that insulin-sensitizing hormones, including leptin and adiponectin, were significantly associated with the survival of centenarians, indicating that an efficient insulin response may influence human longevity.
authors.affiliation: Department of Internal Medicine, Division of Geriatric Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjukuku, Tokyo 160-8582, Japan. yasumich@sc.itc.keio.ac.jp
authors.forename: Yasumichi
authors.initials: Y
authors.lastname: Arai
authors.forename: Toshio
authors.initials: T
authors.lastname: Kojima
authors.forename: Michiyo
authors.initials: M
authors.lastname: Takayama
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Hirose
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D006801:Humans; D007328:Insulin / Q000502:physiology*; D007333:Insulin Resistance / Q000235:genetics / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D008136:Longevity / Q000235:genetics / Q000502:physiology; D024821:Metabolic Syndrome / Q000209:etiology*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
chemical_list: D007328:Insulin; D007334:Insulin-Like Growth Factor I