Big win in the battle against diabetes

Apr 29 2007

In newly published research scientists have revealed that they have discovered more genes linked to Type 2 Diabetes.

The researchers believe their discovery will achieve a better understanding of the origins and progression of the disease.

Research teams from the University of Michigan, the National Human Genome Research Institute, the University of Southern California, the University of North Carolina and Finland's National Health Institute, say they have identified at least four new genetic variants associated with an increased risk of diabetes and have also confirmed the existence of another six.

In what represents the most comprehensive study of genetic risk factors for type 2 diabetes to date, the researchers say a major milestone has been reached in the battle against diabetes.

They say the research will accelerate efforts to understand the genetic risk factors for this disease and how the genetic factors interact with each other and with lifestyle factors.

Type 2 diabetes affects nearly 21 million in the United States, and over 200 million people worldwide and according to the World Health Organization (WHO), the numbers affected will reach 300 million by 2025.

The incidence of diabetes has mushroomed in the last 30 years and is now a major cause of heart disease and stroke, as well as the most common cause in U.S. adults of blindness, kidney failure and amputations not related to trauma.

Type 2 diabetes is characterized by insulin resistance and reduced insulin production which results in glucose building up in the blood instead of being metabolised and used for energy.

For the research the scientists scanned the genomes of more than 2,300 Finnish people who took part in the Finland-United States Investigation of NIDDM Genetics (FUSION) and Finrisk 2002 studies.

Half of the participants had type 2 diabetes and the other half had normal blood glucose levels.

The three research teams found their findings were jointly replicated in smaller, more focused sets of genetic markers in additional groups totaling more than 22,000 people from Finland, Poland, Sweden, the United Kingdom and the United States.

In total the genomes of 32,554 people were tested for the study, making it one of the largest genome-wide association efforts conducted to date.

Although the increase in sedentary lifestyles and rise in obesity is linked to increased numbers for diabetes, many scientists now believe some people's genes make them more vulnerable than others.

The scientists have found three new segments of DNA in the human genome that appear to increase the risk of getting type 2 diabetes by between 10 and 40 per cent.

The scientists also found 8 genes that are common to most people and clearly linked to diabetes type 2, of which 5 were already known to science, and 3 were new.

They also found others that need further investigation and say although the genes are common to most people, there are two common variants of each and while some people may have a variant of a gene that is linked with higher risk, others may have the variant that is linked to a lower risk.

The researchers now believe the total number of genes involved in type 2 diabetes is 9 which includes the FTO gene reported two weeks ago by the UK group , which they suggest plays a role in type 2 diabetes by affecting a person's weight.

At present the role played by the newly discovered genes is unclear, but it has been suggested that two of them might affect the production and action of insulin-producing beta-cells in the pancreas.

Type 2 diabetes is characterized by insulin resistance and reduced insulin production which results in glucose building up in the blood instead of being metabolised and used for energy.

The scientists say it will be some time before the research will have applications which are relevant to patients.

National Institutes of Health (NIH) Director Dr. Elias A. Zerhouni says such research opens the door to the era of personalized medicine which will lead to more individualized strategies based on each person’s unique genetic make-up.

The research is published in the current editions of Science and Nature Genetics.