A major study has shown people with type 2 diabetes have epigenetic changes on their DNA that healthy individuals do not have.

Researchers also found epigenetic changes in a large number of genes that contribute to reduced insulin production.

The significant findings expand the range of known factors for type 2 diabetes, including not only genetic influences but epigenetic ones as well.

Epigenetic changes occur as a result of a person’s environment and lifestyle, and can changes the way some genes are expressed or repressed.

Researcher Charlotte Ling and colleagues have analysed insulin- producing cells of both healthy individuals and patients with type 2 diabetes. The analysis revealed epigenetic changes in around 800 genes in those with type 2 diabetes. Over 100 of the genes also had altered expression and many of these were found to contribute to reduced insulin production. Reduced insulin production is one of the underlying causes of type 2 diabetes.

The researchers also investigated whether healthy individuals had epigenetic changes caused by age, BMI and raised blood sugar levels, to ascertain whether the changes were a cause or result of the presence of diabetes.

“We were able to observe that a number of epigenetic changes had already taken place in healthy subjects as a result of age or high BMI, and were therefore able to conclude that these changes could contribute to the development of the disease,” said Professor Charlotte Ling.

“Unlike genes that can't be changed, epigenetic changes are reversible”, added Tasnim Dayeh, first author of a new publication in PLOS Genetics.

Drugs that cause epigenetic changes have long been used in the treatment of cancer and epilepsy. The new survey changes the view of epigenetics in relation to diabetes, researchers say.

“It shows that epigenetics is of major significance for type 2 diabetes, and can help us to understand why people develop the condition. This also opens the way for the development of future drugs,” Dr Ling said.