Friday, November 01, 2013

Can Your Genes Predict Your Risk For Type 2 Diabetes?

How well does genetic make-up predict risk for type 2 diabetes? This recent review finds that genes aren't a good predictor:

Predicting Risk of Type 2 Diabetes Mellitus with Genetic Risk Models on the Basis of Established Genome-Wide Association Markers: A Systematic Review, American Journal of Epidemiology, Online: September 2013
"In conclusion, [Genetic risk models] showed a low predictive performance for risk of type 2 diabetes, irrespective of study design, participants’ race/ethnicity, and the number of genetic markers included."
The researchers analyzed data from 23 studies and found that genetic testing was not as useful as conventional risk factors, e.g. weight and age, in determining risk for type 2 diabetes.

The National Institutes of Health (NIH) gives these conventional risk factors for type 2 diabetes:
  • Age greater than 45 years
  • Diabetes during a previous pregnancy
  • Excess body weight (especially around the waist)
  • Family history of diabetes
  • Given birth to a baby weighing more than 9 pounds
  • HDL cholesterol under 35 mg/dL
  • High blood levels of triglycerides, a type of fat molecule (250 mg/dL or more)
  • High blood pressure (greater than or equal to 140/90 mmHg)
  • Impaired glucose tolerance
  • Low activity level (exercising less than 3 times a week)
  • Metabolic syndrome
  • Polycystic ovarian syndrome
  • A condition called acanthosis nigricans, which causes dark, thickened skin around the neck or armpits
NIH recommends that everyone over age 45 have a blood sugar (glucose) test at least every 3 years, more often if there is a higher risk for diabetes.