Extended life in lean subjects may be due to improved insulin signaling in adipose tissue

Extended longevity in lean individuals may be due to the prevention of obesity-related metabolic disorders.

According to a recent review published in the journal Experimental Gerontology, "Caloric restriction and leanness have been shown to increase longevity in organisms ranging from yeast to mammals. Adipose tissue seems to be a pivotal organ in the aging process and in determination of lifespan."

N. Kloting and M. Bluher at the University Cologne summarized, "We have recently shown that fat-specific disruption of the insulin receptor gene is sufficient to increase lifespan in FIRKO mice, suggesting that reduced adiposity, even in the presence of normal or increased food intake, can extend lifespan. The model also suggests a special role for the insulin-signaling pathway in adipose tissue in the longevity process. Reduced fat mass has an impact on the duration of life in several other model organisms."

"In Drosophila," they continued, "a specific reduction in the fat body through overexpression of forkhead type transcription factor (dFOXO) extends lifespan. Furthermore, sirtuin 1 (SIRT1), the mammalian ortholog of the life-extending yeast gene silent information regulator 2 (SIR2), was proposed to be involved in the molecular mechanisms linking lifespan to adipose tissue. In the control of human aging and longevity, one of the striking physiological characteristics identified in centenarians is their greatly increased insulin sensitivity even compared with younger individuals."

The authors proposed, "The effect of reduced adipose tissue mass on lifespan could be due to the prevention of obesity-related metabolic disorders including type 2 diabetes and atherosclerosis."

Kloting and Bluher published their study in Experimental Gerontology (Extended longevity and insulin signaling in adipose tissue. Exp Gerontol, 2005;40(11):878-883).

For additional information, contact M. Bluher, University of Cologne, Dept. Internal Medicine 2, Kerpener Str 62, D-50924 Cologne, Germany.

The publisher's contact information for the journal Experimental Gerontology is: Pergamon-Elsevier Science Ltd., the Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, England.

Keywords: Cologne, Germany, Adipose Tissue, Aipose Tissue, Atherosclerosis, Centenarians, dFOXO, Diabetes, FIRKO, Geriatric, Gerontology, Insulin Signaling, Longevity, Metabolic Disorders, Metabolism, Obesity, SIRT1, Type 2 Diabetes, Drosophila. This article was prepared by Aging & Elder Health Week editors from staff and other reports. Copyright 2006, Aging & Elder Health Week via NewsRx.com.