Diabetes, Heart Disease Share "Risk Genes"

Scientists have found gene variants that appear to alter the risk of both type 2 diabetes and heart disease in a new genome study involving 250,000 people. The discovery may lead to treatments designed to protect against both illnesses. The paper was published in the journal Nature Genetics.

The international team of researchers was helmed by a team at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. About 95 percent of diabetes patients suffer from type 2 diabetes, a condition where cells lose much of their ability to absorb insulin.

The rate of diabetes globally has doubled while the rate in the United States has tripled. Heart disease is a known risk factor for diabetics.

Heart disease is the leading cause of death for both men and women in the U.S. The study found that patients with type 2 diabetes were twice as likely to have coronary heart disease versus patients who are not diabetic. The genetics of this problem are poorly understood, however, and the genome study hoped to find closer ties.

A new genome-wide association study method has allowed scientists to sequence genomes (complete sets of DNA) in order to find specific loci (parts) linked to a disease. By comparing links for more than one disease, correlations can be found and further examined. In this study, the researchers found molecular pathways in the genome that are associated with both type 2 diabetes and heart disease.

Of the genomes examined (about 250,000), most were of European and Asian descent. Known risk loci for diabetes were confirmed while 16 more were discovered. One new one for coronary heart disease was also found. Most of the known loci for type 2 diabetes were also associated with higher risk of coronary heart disease, making a clear connection.

The team was able to isolate eight of those loci as specific variants that alter the risk for both conditions. That means that at least eight gene variants are clearly associated with both type 2 diabetes and heart disease.

Joint senior study author Danish Saleheen, an assistant professor of biostatistics and epidemiology at the University of Pennsylvania, suggests, "Identifying these gene variants linked to both type 2 diabetes and CHD [coronary heart disease] risk in principle opens up opportunities to lower the risk of both outcomes with a single drug."

The team may also have found why some statin drugs used to lower cholesterol have the unusual effect of slightly raising diabetes risks. Further, the team found that the links identified for the two diseases in tandem are tied closely, making the risks for both diseases significantly more likely rather than raising one risk more than the other.

The researchers plan to continue narrowing their findings.

Source: Medicalnewstoday.com