News article

Swedish study on identical twins sheds light on mechanisms behind the development of type 2 diabetes

Posted:  Thursday, October 16, 2014

The mechanisms that lead to the development of type 2 diabetes have always been a topic of intense research. Now, in a recent study, Swedish researchers have identified the probable mechanisms behind the development of type 2 diabetes.

As a part of the study, the researchers studied 14 sets of identical twins from Denmark and Sweden. Among each pair of twins, one of the twins had diabetes, while the other was healthy. Though these studies have been done on identical twins who are a good model for studying mechanisms, the results apply to all.

Fat tissues are known to release hormones and regulate metabolism in different organs. Hence, the researchers questioned whether epigenetic changes in the DNA lead to changes in the fat tissue, which could subsequently lead to development of type 2 diabetes.

The researchers investigated DNA methylation at 480, 000 points on the DNA and examined the way it affected the expression of the genes in the identical twins.

They found that in the diabetic twins, the genes responsible for inflammation were upregulated whereas those responsible for fat and glucose metabolism were downregulated. The resultant excess circulating fat is not utilised well, resulting in its uptake by the liver, pancreas and muscle. This leads to insulin resistance and the development of type 2 diabetes.

The researchers found that the twins had similar DNA methylation which suggests strong heredity.

They additionally compared non-identical twins with identical twins and found greater similarities in identical twins. “Non-identical twins generally share 50 per cent of their DNA and it is usually said that identical twins share 100 per cent of theirs. Despite this, we found 1400 places on the identical twins’ DNA where there was a difference in DNA methylation between the diabetic and the non-diabetic. It is believed that these differences are due to differences in lifestyle and this confirms the theory that type 2 diabetes is strongly linked to lifestyle,” said lead researcher Emma Nilsson.

Additionally, the researchers made another novel discovery. They found that there were certain changes in the actual DNA sequence between the diabetic and non-diabetic twin. They found 6 such cases where one of the set of twins had more or fewer copies of a certain DNA sequence . The researchers hypothesize that this could also contribute to the increased risk of type 2 diabetes.

The present study has brought into focus the key role aspects such as diet and lifestyle play in effecting changes at the genome level and subsequently modifying susceptibility to diseases.

For study details:-Click Here!