Higher IGF-1 increases life expectancy?

[Guest guest]

Hi All,

The podcast from science was especially informative, was just less than seven minutes for the interview and is:

http://tinyurl.com/3sjrcb

Suh Y, Atzmon G, Cho MO, Hwang D, Liu B, Leahy DJ, Barzilai N, Cohen P.Functionally significant insulin-like growth factor I receptor mutations in centenarians.Proc Natl Acad Sci U S A. 2008 Mar 4;105(9):3438-42. Epub 2008 Mar 3.PMID: 18316725 http://tinyurl.com/43byop

Adler EM, Foley JF.Science Signaling Podcast: 08 April 2008.Sci Signal. 2008 Apr 8;1(14):pc3.PMID: 18398106

This conversation is about research highlighted in Editors' Choice titled "Predisposed to a Long Life?" The highlighted article is Y. Suh, G. Atzmon, M.-O. Cho, D. Hwang, B. Liu, D. J. Leahy, N. Barzilai, P. Cohen, Functionally significant insulin-like growth factor I receptor mutations in centenarians. Proc. Natl. Acad. Sci. U.S.A. 105, 3438-3442 (2008). (Length: 7 min; file size: 3.29 MB; file format: mp3; location: http://podcasts.aaas.org/science_signaling/ScienceSignaling_080408.mp3).

Sci. Signal., 11 March 2008. Vol. 1, Issue 10, p. ec91EDITORS' CHOICELife SpanPredisposed to a Long Life? M. Adler

Mutations that disrupt growth hormone production or sensitivity and thereby lead to decreased serum concentrations of insulin-like growth factor 1 (IGF-1) are associated with increased longevity in mice. Furthermore, decreased abundance of the IGF-1 receptor (IGF1R) is associated with increased life span in female mice, and mutations that decrease the activity of components of the insulin/IGF-1 system are associated with increased longevity in invertebrates. The role of IGF-1 signaling in human longevity, however, is less clear. Indeed, growth hormone secretion and serum concentrations of IGF-1 decline with age, and administration of growth hormone (which increases circulating IGF-1) may reverse some physiological correlates of aging. Suh et al. found that the daughters of centenarians had 35% higher serum IGF-1 concentrations than age-matched women of similar ethnic background (Ashkenazi Jews) from families that were not so long-lived. Additionally,

the average maximum height attained by the centenarians¢ daughters was 2.5 cm less than that of their control group. Sequence analysis revealed no variations in the IGF1 genes of 79 female centenarians who were shorter than the mean height but showed 20 IGF1R sequence variants. Two nonsynonymous heterozygous mutations of IGF1R coding regions were more common in centenarians than in controls and were associated with increased serum IGF1. Immortalized lymphocytes from three centenarians, each carrying a different IGF1R mutation, showed decreased IGF1R abundance compared with lymphocytes from centenarians without IGF1R mutations and decreased phosphorylation of Akt in response to IGF-1. Thus, the authors conclude that human IGF1R mutations that affect IGF signaling may be associated with a predisposition toward long life.