http://www.mercola.com/2003/feb/8/longevity.htm


Extended longevity in mice lacking the insulin receptor in adipose tissue.

Bluher M, Kahn BB, Kahn CR.

Joslin Diabetes Center and Department of Medicine, Harvard Medical School,
One Joslin Place, Boston, MA, 02215 USA.

Caloric restriction has been shown to increase longevity in organisms
ranging from yeast to mammals. In some organisms, this has been associated
with a decreased fat mass and alterations in insulin/insulin-like growth
factor 1 (IGF-1) pathways. To further explore these associations with
enhanced longevity, we studied mice with a fat-specific insulin receptor
knockout (FIRKO). These animals have reduced fat mass and are protected
against age-related obesity and its subsequent metabolic abnormalities,
although their food intake is normal. Both male and female FIRKO mice were
found to have an increase in mean life-span of approximately 134 days (18%),
with parallel increases in median and maximum life-spans. Thus, a reduction
of fat mass without caloric restriction can be associated with increased
longevity in mice, possibly through effects on insulin signaling.

PMID: 12543978 [PubMed - indexed for MEDLINE]