In a recent study, researchers at Virginia Tech discovered that pre-diabetic people who were unable to effectively respond to insulin (insulin resistant) also had altered mitochondrial DNA. The details of the study can be seen in Clinical Epigenetics.
For the study, the researchers took blood samples from 40 participants who were enrolled in a diabetes-fighting program called diaBEAT-it. Many researchers in the Fralin Translational Obesity Research Center run diaBEAT-it, which is funded by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases.
The 40 participants chosen for the study exhibited signs of insulin resistance (meaning they were pre-diabetic) but did not have any cardiovascular disease or diabetes.
When the team of researchers analyzed the blood samples, they found the participants had reduced quantities of mitochondrial DNA with a greater volume of methylation than healthy people. Methylation is a process by which methyl groups are added to the DNA, and this process can change the genetic expression and mitochondrial copy numbers in cells.
Mitochondria are the power plants of the cells and are responsible for converting chemical energy from food into energy that cells can use.
According to Zhiyong Cheng, an assistant professor of human, nutrition, foods and exercise, if the body is unable to react appropriately to insulin (as is seen in the case of pre-diabetic people), it could affect a person’s mitochondrial function and overall energy levels.
Earlier studies revealed alterations in the mitochondria in obese people, but never before has a molecular link been made between insulin resistance and mitochondrial DNA changes.
The team of researchers think this link could be useful to determine which people are pre-diabetic individuals, and thereby help prevent the onset of type-2 diabetes.
According to NIH statistics, more than 66 percent of adults in the U.S. are considered to be overweight. And more than 33 percent fall into the obese category. The reasons why obesity is becoming an epidemic in the U.S. are basically a combination of overeating and under-exercising – taking in more food calories than the body burns through physical activity. Obesity is a high-risk factor for type-2 diabetes and most type-2 diabetic patients are obese.
As there is no known cure for type-2 diabetes, spotting it before the onset of symptoms and intervening accordingly can help prevent this disease. Discovery of the DNA biomarker in obese, pre-diabetic individuals is a big step in the right direction in our effort to learn more about how diabetes develops. The study provides data to apply the learnings to future diagnosis and intervention.
Sources:
http://www.vtnews.vt.edu/articles/2015/08/081915-fralin-prediabetes.html
http://www.clinicalepigeneticsjournal.com/content/7/1/60