|New study suggest that obesity greatly accelerates|
aging of the liver.
Using a recently developed biomarker of aging known as an epigenetic clock, researchers have for the first time found 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. The findings appear Oct. 13, 2014, in the early online edition of the peer-reviewed journal Proceedings of the National Academy of Sciences.
In the study, the researchers looked at almost 1200 human 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, the researchers 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. It also found that rapid weight loss induced by bariatric surgery did not reverse the accelerated aging, at least in the short term.
Going forward, the 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.