Significant relationship between mortality and telomere length discovered

Public release date: 8-Nov-2012 [ | E-mail | Share ]

Contact: Cathy Yarbrough press@ashg.org 858-243-1814 American Society of Human Genetics

A team of researchers at Kaiser Permanente and the University of California, San Francisco (UCSF) has identified a significant relationship between mortality and the length of telomeres, the stretches of DNA that protect the ends of chromosomes, according to a presentation on Nov. 8 at the American Society of Human Genetics 2012 meeting in San Francisco.

While a reduction in telomere length is regarded as a biomarker of aging, scientists have not yet determined whether it plays a direct causal role in aging-related health changes and mortality or is just a sign of aging.

In their prospective study of 100,000 multi-ethnic individuals whose average age was 63 years, the researchers determined that an association between telomere length and mortality existed and persisted even after the data were adjusted for such demographic and behavioral factors as education, smoking and alcohol consumption, said Catherine Schaefer, Ph.D., director of the Kaiser Permanente (KP) Research Program on Genes, Environment and Health (RPGEH).

Dr. Schaefer and Neil Risch, Ph.D., director of the UCSF Institute for Human Genetics, are principal investigators of the Genetic Epidemiology Research Study on Adult Health and Aging (GERA). UCSF professor and Nobel laureate Elizabeth Blackburn, Ph.D., led the research on telomere length measurement.

The telomere research, part of the GERA project, has genotyped over 675,000 markers of 100,000 KP Northern California patients and linked them with health data from their electronic medical records. To obtain DNA for genotyping and telomere measurement, the researchers collected saliva samples from the patients, who volunteered for the project and provided scientists with access to their electronic medical records.

Two years prior to the saliva collection, the researchers conducted a detailed survey of the patients' demographic and behavioral factors, providing a unique opportunity to address questions of telomere epidemiology and aging.

"With these data, we examined demographic relationships with telomere length, behavioral influences and relationship of telomere length with all causes of mortality following sample collection," said Dr. Schaefer. "Although we found that shorter-than-average telomeres were prospectively associated with mortality, only those with the shortest telomeres were at increased risk of death."

Dr. Risch added, "While this could indicate a direct effect of telomere length on health, it will also be important to examine the extent of pre-existing diseases in these individuals to understand their possible role in the biological connection between telomere length and longevity."

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Significant relationship between mortality and telomere length discovered