(Press-News.org) Using a recently developed biomarker of aging known as an epigenetic clock, UCLA researchers working closely with a German team of investigators have found for the first time that obesity greatly accelerates aging of the liver. This finding could explain the early onset of many age-related diseases, including liver cancer, in obese subjects
Although it had long been suspected that obesity ages a person faster, it hadn't been possible to prove the theory, said study first author Steve Horvath, a professor of human genetics at the David Geffen School of Medicine at UCLA and a professor of biostatistics at the UCLA Fielding School of Public Health. Using the epigenetic clock Horvath developed last year, he and Jochen Hampe from the University Hospital Dresden showed that carrying excessive weight can negatively impact select human tissues.
"This is the first study that evaluated the effect of body weight on the biological ages of a variety of human tissues," Horvath said. "Given the obesity epidemic in the Western world, the results of this study are highly relevant for public health."
The findings appear Oct. 13, 2014, in the early online edition of the peer-reviewed journal Proceedings of the National Academy of Sciences.
Horvath's aging clock uses a previously unknown time-keeping mechanism in the body to accurately gauge the age of diverse human organs, tissues and cell types. He and his collaborators focused on a naturally occurring process called methylation, a chemical modification of the DNA molecule.
Horvath used this epigenetic clock to measure the biological age of several tissues. The aging clock proved accurate in matching biological to chronological age in lean subjects. But liver tissues from obese subjects tended to have a higher biological age than expected.
In this study, Horvath looked at almost 1200human tissue samples, including 140 liver samples, to study the relationship between epigenetic age acceleration and body weight. While obesity doesn't affect the epigenetic age of fat, muscle or blood tissue, he and his collaborators found that, on average, the epigenetic age of the liver increased by 3.3 years for every 10 Body Mass Index (BMI) units.
For example, a woman who is 5 feet 5 and weighs 140 pounds has a BMI of 23.3. A woman the same height but weighing 200 pounds would have a body mass index of 33.3. Her liver would be about three years older than the woman who weighed 140 pounds, the study found.
"This does not sound like a lot, but it is actually a very strong effect," Horvath said. "For some people, the age acceleration due to obesity will be much more severe, even up to 10 years older."
Horvath also found that rapid weight loss induced by bariatric surgery did not reverse the accelerated aging, at least in the short term.
Going forward, Horvath and his team want to determine if the premature epigenetic aging of liver tissue in obese people can be prevented to possibly reduce their risk of diabetes and liver cancer. They plan to work on models that allow them to dissect the exact molecular mechanisms behind this aging process - which is not known at this point - in order to find the right targets for therapy and prevention.
"The increased epigenetic age of liver tissue in obese individuals should provide insights into common liver-related comorbidities of obesity, such as insulin resistance and liver cancer," the study states. "These findings support the hypothesis that obesity is associated with accelerated aging effects and stresses once more the importance of maintaining a healthy weight."
INFORMATION:
The study was funded by the National Institutes of Health (NIA/HIH 5RO1AG04511-02), the Virtual Liver Network, the Christian-Albrechts-University Kiel and the University Hospitals Schleswig-Holstein and Dresden in Germany.
The ideal cost per dose for a new meningitis vaccine ranges from £3 up to a possible £22 only if several vaccine favourable factors all coincide, according to research which has analysed how to maximise the reduction in cases while making a new vaccination programme cost-effective.
Bexsero is the first vaccine to broadly protect against meningitis B disease, but research now suggests the Government would need to negotiate a considerable reduction in the £75 list price in order to provide the same value for money as other programmes in the NHS.
In March ...
Proteins regulating cell division determine tumour growth. Ongoing clinical trials are currently studying inhibitors for two of these proteins, Cdk4 and Cdk6, targeting several types of cancer, such as breast cancer, lung cancer and leukaemia. The Cell Division and Cancer Group at the Spanish National Cancer Research Centre (CNIO), led by Marcos Malumbres, has discovered the molecular mechanism behind the interaction of these proteins. Researchers also demonstrated in mice that the simultaneous inhibition of both molecules is more effective than the individual inhibition. ...
Focusing on large, star-forming galaxies, researchers at the Johns Hopkins University were able to measure radiation leaks in an effort to better understand how the universe evolved as the first stars were formed.
Sanchayeeta Borthakur, an assistant research scientist in the Department of Physics and Astronomy in the university's Krieger School of Arts and Sciences, reports in a paper published online Oct. 9 in the journal Science that an indicator used for studying star-forming galaxies that leak radiation is an effective measurement tool for other scientists to use. ...
(PHILADELPHIA) – Some cancers, like breast and prostate cancer, are driven by hormones such as estrogen and testosterone, but to date, there are none that are driven by the lack of a hormone. New evidence suggests that human colon cells may become cancerous when they lose the ability to produce a hormone that helps the cells maintain normal biology. If verified by further studies, it suggests that treating patients at high risk for colon cancer by replacing the hormone guanylin could prevent the development of cancer.
The researchers at Thomas Jefferson University ...
PHILADELPHIA — Higher levels of total cholesterol and triglycerides, two types of fat, in the blood of men who underwent surgery for prostate cancer, were associated with increased risk for disease recurrence, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
"While laboratory studies support an important role for cholesterol in prostate cancer, population-based evidence linking cholesterol and prostate cancer is mixed," said Emma Allott, PhD, postdoctoral associate at Duke ...
Intensive parenting and health education provided in homes of pregnant American Indian teens reduced the mothers' illegal drug use, depression and behavior problems, and set their young children on track to meet behavioral and emotional milestones they may have otherwise missed.
The Johns Hopkins Bloomberg School of Public Health-led research also suggests that employing local community health educators instead of more formally educated nurses to counsel young at-risk mothers could be cost effective and provide badly needed jobs to high school graduates from the same ...
Adoption of a combination of five key healthy behaviors is associated with a reduction in the risk of developing bowel cancer. Researchers from the German Institute of Human Nutrition Potsdam-Rehbruecke quantified the impact of combined multiple healthy lifestyle behaviors on the risk of developing bowel cancer, and found that this impact is stronger in men than in women.
Lead author, Krasimira Aleksandrova, says: "These data provide additional incentive to individuals, medical professionals and public health authorities to invest in healthy lifestyle initiatives. Each ...
The sanitation intervention delivered under the terms of the Government of India's Total Sanitation Campaign—the world's largest sanitation initiative—provided almost 25 000 individuals in rural India with access to a latrine. However, it did not reduce exposure to faecal pathogens or decrease the occurrence of diarrhoea, parasitic worm infections, or child malnutrition.
"The programme is effective in building latrines, but not all households participate"*, explains lead author Professor Thomas Clasen from Emory University, Atlanta, USA and the London School ...
Washington, DC (October 9, 2014) — Recent policy and guideline changes related to the care of patients with kidney failure have not created racial disparities, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). Such studies are needed to ensure that all patients continue to receive the highest quality of care after such changes are implemented.
In 2011, the End-Stage Renal Disease Prospective Payment System went into effect, which changed the way dialysis facilities were paid for care related to kidney ...
WEST LAFAYETTE, Ind. – An emerging class of electrically conductive plastics called "radical polymers" may bring low-cost, transparent solar cells, flexible and lightweight batteries and ultrathin antistatic coatings for consumer electronics and aircraft.
Researchers have established the solid-state electrical properties of one such polymer, called PTMA, which is about 10 times more electrically conductive than common semiconducting polymers.
"It's a polymer glass that conducts charge, which seems like a contradiction because glasses are usually insulators," said ...
