Type 2 diabetes has a strong hereditary component, and while we can't change the genes we were born with, if epigenetics says a father eating a Twinkie before conception can lead to bad grades for the child in high school, why can't we modify the function of the genes through the epigenetic changes that take place in the course of life?
Perhaps we can, according to a study from Lund University in Sweden. Epigenetic changes are usually described as a link between heredity and environment and come about as a result of factors like medication, diet and drugs and the researchers from Lund have now demonstrated that half of the known genetic risk variants for type 2 diabetes can be influenced by epigenetic changes that in turn influence the function of the insulin-producing cells.
The epigenetic factor that has been studied is a chemical change on the DNA strand following a certain pattern - DNA methylation.
"This means that we gain a tool to influence the function of the risk genes, improve insulin release and thereby reduce the risk of diabetes", says Charlotte Ling at Lund University Diabetes Centre. "We have shown that 19 of 40 known genetic risk variants for type 2 diabetes are affected by DNA methylation, which in turn changes the function of the insulin-producing cells. This is important. Many researchers have put a lot of time and resources into mapping our genome and finding genetic risk markers for diabetes and other diseases. We know that there are genetic variants that increase the risk of type 2 diabetes, but in most cases the reasons why this happens are still not known.
"The next step is to find this out and after this study of the genetic risk variants, we can say that in some cases the increased risk is probably due to varying degrees of DNA methylation."
The research group has studied insulin-producing cells from 84 deceased donors, the first epigenetic study to be carried out on the 40 risk markers for type 2 diabetes.
The present study shows that DNA methylation of genetic risk variants for diabetes influence the insulin-producing cells in various different ways, such as the amount of insulin they contain and the amount they are able to release into the blood stream.
"The next step in our work is to test whether we can reduce the risk of type 2 diabetes by changing the degree of DNA methylation in the genetic risk variants for the disease."
Published in Diabetologia.