An important way to relate life span and genetic features has been found in a new study on telomeres. A group of collaborators from the San Francisco campus of the University of California (UCSF) and Kaiser Permanente discovered how the ends of chromosomes are protected by parts of DNA. The length of these parts, known as telomeres, relates to deterioration of health. They presented their findings at the 2012 meeting of the American Society of Human Genetics in San Francisco on the 8th of November.
The data suggests that telomeres get shorter as people age. There is some question whether there is a direct relationship between the shorter pieces of genetic material and causes of age-related illnesses, or if it merely a sign that people are getting older.
The study considered 100,000 subjects based on different ethnic backgrounds who averaged 63 years old. The research showed a relationship between the length of telomeres and mortality regardless of other factors including demographics, education, and behaviors like drinking alcohol or smoking cigarettes, according to the Kaiser Permanente Research Program on Genes, Environment, and Health director, Catherine Schaefer, Ph.D.
The research into measuring the length of telomeres was led by Elizabeth Blackburn, Ph.D., a Nobel Laureate and professor at UCSF. The main research was carried out by the director of the Institute for Human Genetics at UCSF, Neil Risch, Ph.D., and Dr. Schaefer, as part of the Genetic Epidemiology Research Study on Adult Health and Aging (GERA).
As part of this project, Northern California Kaiser Permanente associated health data from electronic records of 100,000 patients with 675,000 genotyped markers. Volunteers granted access to their medical records and donated samples of saliva for genotyping the
DNA and measuring the telomeres.
Surveys of the volunteers behaviors and demographics that might affect health were made two years before the samples were collected. This was to help consider questions regarding the epidemiology of telomeres and aging.
According to Dr. Schaefer, “With these data, we examined demographic relationships with telomere length, behavioral influences and relationship of telomere length with all causes of morality following sample collection.” She also added, “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.”
“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,” said Dr. Risch.
While the analyses were controlled for both age and gender, Dr. Risch said the researchers found what they expected. Telomeres were shorter in older people and they were longer for women than men, with young adults representing the exception.
Dr. Cynthia Morton, Ph.D., Harvard’s William Lambert Richardson Professor in the department of obstetrics, gynecology, and reproductive biology said, “The GERA study is especially impressive for the large resource of DNA samples and corresponding electronic
medical records available from KP patients, and for the outstanding group of scientists collaborating in the research,” even though she was not part of the study.
The study reveals length of telomeres has a positive association with body mass index and the amount of education a person has. There is a negative relationship to alcohol and tobacco use, but not with disorders correlated with stress or depression. Other research has found a relationship with depression or stress and the length of telomeres.
There is a relationship between shorter telomeres and dangers like cardiovascular disease, pulmonary fibrosis, depression, diabetes, vascular dementia, cancers, osteoporosis and osteoarthritis. This is because the telomeres are unique DNA sequences at the ends of the chromosomes in every human cell. When they are too short, multiplication of cells is no longer possible. These links have been detected by research labs in addition to Dr. Blackburn, who won the 2009 Nobel Prize in Physiology or Medicine along with two other researchers.
The study was presented with the title, “The Kaiser Permanente/UCSF Genetic Epidemiology Research Study on Adult Health and Aging: Demographic and Behavioral Influences on Telomeres and Relationship with All-cause Mortality.”
The American Society of Human Genetics (ASHG) is a professional group for almost 8,000 geneticists from around he world. The Annual Meeting is the largest of its kind in the world.
Please note: product statements have not been evaluated by the Food and Drug Administration or their equivalent organisation in any country. No product is intended to diagnose, treat, cure or prevent any disease.