Research links genetic variant and poor diabetes control to coronary artery disease

A recent study has shown that a common genetic variation which increases the risk of developing coronary artery disease (CAD) in the general population, has a greater effect in those with type two diabetes. The study, led by Dr Alessandro Doria at the Joslin Diabetes Centre, Harvard Medical School, Boston, was published in the journal JAMA last week.

'Coronary artery disease is one of the leading causes of death in this country [US] and diabetes is a major risk factor for CAD,' said Dr Doria. 'But not everybody with diabetes is at the same risk. The extent to which high glucose damages the coronary arteries seems to be genetically determined.'

The researchers suggest that the findings may help doctors identify people with diabetes who are at a higher risk of CAD at an earlier stage, allowing them to be targeted with interventions.

The research incorporated two separate studies. The first included 742 type two diabetes patients; 322 with CAD and 412 without. The study found that participants with two copies of the genetic variant, coupled with poor glucose control, had a four-fold increased risk of CAD, while those who had two copies of the variant but better glucose control saw their risk of CAD increase only two-fold. This was compared to those in the study with no copies of the genetic variant and better glucose control. There was almost no increase in CAD risk among people with poor glucose control unless the genetic variant was also present.

A similar interaction between the genetic variant and poor glucose control was observed in the second study. This included 475 people with type 2 diabetes who were monitored for 10 years. The genetic variation is located on chromosome 9. The researchers conclude that in their study, the CAD risk associated with the genetic variant was increased in the presence of poor glycaemic control in type 2 diabetes.