Want to know your diabetes risk?  No need to visit a genetic testing laboratory!  A new study published in the Nov 20 2008 issue of the New England Journal of Medicine suggests that use of a set of 16 genetic variants is not significantly better than use of common clinical risk factors when it comes to predicting the risk of type 2 diabetes.

The study was conducted by researchers from Lund University, Malmö, Sweden, the University of Helsinki and the Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, and Massachusetts General Hospital, Boston.

The notion that type 2 diabetes mellitus results from an interaction between environmental and genetic factors led the researchers to believe that genetic variants could be better predict the risk of type 2 diabetes than clinical factors.

In the study, Lyssenko V and colleagues conducted DNA genetic testing for 16 genes and examined clinical factors in 16,000 Swedish and 2770 Finnish subjects.   Type 2 diabetes were diagnosed in 2201 or 11.7 percent of the subjects during the average 23.5-year follow-up.

Conventional predictors of diabetes include family history of diabetes, high body mass index, elevated liver-enzyme levels, smoking status and reduced measures of insulin secretion and action.

The genetic variants studied include those in 11 genes (TCF7L2, PPARG, FTO, KCNJ11, NOTCH2, WFS1, CDKAL1, IGF2BP2, SLC30A8, JAZF1, and HHEX), which were significantly associated with the risk of type 2 diabetes independently of clinical risk factors and 8 of these genes which were associated with impaired beta-cell function.

The researchers found that adding genetic information to clinical factors slightly improved the prediction of future diabetes. The significance of genetic variants in the predictability increased with the increasing duration of follow-up.

They concluded that "As compared with clinical risk factors alone, common genetic variants associated with the risk of diabetes had a small effect on the ability to predict the future development of type 2 diabetes. The value of genetic factors increased with an increasing duration of follow-up."

But overall, genetics testing employed in this study does not seem to be superior to the traditional assessment on the diabetes risk based on clinical parameters.

Source:

New England Journal of Medicine. 2008 Nov 20;359(21):2220-2232.

Clinical Risk Factors, DNA Variants, and the Development of Type 2 Diabetes.

Lyssenko V, Jonsson A, Almgren P, Pulizzi N, Isomaa B, Tuomi T, Berglund G, Altshuler D, Nilsson P, Groop L.

From the Department of Clinical Sciences, Lund University, Malmö, Sweden (V.L., A.J., P.A., G.B., P.N., L.G.); the University of Pisa, Pisa, Italy (N.P.); the Folkhalsan Research Center (B.I., T.T.) and Helsinki University Central Hospital and the University of Helsinki (T.T., L.G.) - all in Helsinki, Finland; and the Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, and Massachusetts General Hospital, Boston (D.A.).