Life Span Lives in Length of Chromosomes
Tips of Chromosomes Shorten With Age, Lead to Age-Related Disease, Death
Jan 31, 2003 -- Researchers are one step closer to understanding what makes us age. The answer lies in the length of our chromosomes. In fact, some day it may be possible to intervene to preserve this length, and thereby extend life, say scientists from the University of Utah.
Their study appears in the Feb. 1 issue of TheLancet.
In it, they describe the importance of "telomeres," the tips of chromosomes. These ends shorten normally with age. But people with the genetic disorder called dyskeratosis congenita -- which involves premature onset of many age-related diseases and early death -- have an accelerated shortening of telomeres.
Until now, however, it's not been known whether people with longer telomeres live longer than those with shorter telomeres.
Researchers studied 143 people over age 60, taking blood samples to measure their telomere length. Those in the top half for telomere length lived four to five years longer than those in the bottom half. The study showed no difference in the shortening rate of telomeres between men and women.
Those with shorter telomeres had higher death rates, with three times greater risk of death from heart disease and nearly a nine times higher risk of death from infectious diseases.
Numerous environmental and genetic factors can affect telomere length, writes lead researcher Richard M. Cawthon, PhD.
"This is the first research study showing that telomere length is predictive of survival in humans. It supports the hypothesis that telomere shortening is a fundamental process of aging, contributing to mortality from multiple age-related diseases. If this is correct, then it may be possible to extend the duration of healthy adult life using medical interventions that maintain telomere length."