22 May 2014
Researchers have found strong evidence that the contribution of genetic factors to the risk of developing type 2 diabetes is greatest in younger and leaner individuals.
Type 2 diabetes, which accounts for 90% of all diabetes cases, is a complex disease known to involve both genetic and environmental factors, but the interactions between them in determining risk are not well understood.
The researchers examined genetic and lifestyle information along with medical data from over 340,000 European people and over more than 11 years (the EPIC-InterAct study), over which period more than 12,000 developed type 2 diabetes. Risk factors including age, physical activity and diet were considered as well as measures of obesity (BMI and waist circumference), but no interactions with genetic risk were identified other than those observed for obesity and overweight.
They found that the 10-year incidence of the disease was substantially greater for those with the lowest genetic risk who were overweight (1.29%) or obese (4.22%), than for normal weight individuals with the highest genetic risk (0.89%). They therefore propose that targeted interventions based on genetic risk are unlikely to be of value for prevention of type 2 diabetes and that the focus should remain on population-wide strategies to promote healthy lifestyles and prevent obesity.
These findings support the conclusions of a PHG Foundation briefing earlier this year; The genomic contribution to diabetes concluded that there was no evidence to support genetic risk profiling as part of screening to identify those at the greatest risk of developing Type 2 diabetes and saying that it therefore ‘remains a public health priority to promote healthy lifestyle choices in preventing the onset of diabetes’. However, as with obesity itself, genetic testing may be of clinical benefit in some individuals for the diagnosis other, rarer sub-groups of diabetes.