Genetic variant increases success of type 2 diabetes treatment

A genetic variation in the CYP2C9 gene is associated with how people with type 2 diabetes respond to a group of anti-diabetic drugs called sulphonylureas, according to a new study.

The research, carried out by the Diabetes Research Group at the University of Dundee, assessed 1073 type 2 diabetes in Tayside over 18 months. They found that six people in every 100 had two copies of the CYP2C9 gene variant, and that they were 3.4 times more likely to achieve their blood glucose target levels.

Dr Iain Frame, Director of Research at Diabetes UK, explained: 'The CYP2C9 gene produces an enzyme which breaks down sulphonylureas in the liver. In people with variations in this gene the enzyme is less active, which could explain their improved response to sulphonylureas'.

There are currently 2.25 million people with type 2 diabetes in the UK, a quarter of whom are treated with sulphonylureas. These drugs help to control blood glucose levels by increasing the release of insulin from the beta cells in the pancreas. Good control of blood glucose helps prevent complications of diabetes such as heart disease and renal failure.

This is the first study demonstrating a large effect of genetic variation on response to diabetes drugs, making this form of diabetes treatment another example of 'personalised' medicine. Identifying who is more likely to benefit from certain treatments could help doctors when prescribing medicine.

'This study adds to the pharmacogenetic field of research which may in time lead to better tailored prescriptions for people with type 2 diabetes so that treatment is optimised in light of a person's genetic make-up. This could in turn eventually lead to a reduction in the amount of money that is spent on ineffective diabetes drug treatments by the NHS', Dr Frame said.