People with poor lifestyle and obesity are at greater risk of incident type 2 diabetes regardless of their genetic risk, according to new research to be presented this week at the Annual Meeting of the European Association for the Study of Diabetes (EASD), in Barcelona. The study* showed that obese people were nearly six times as likely as non-obese people to go on to develop type 2 diabetes (T2D) – which, said the authors, highlights the importance of weight management in preventing the disease.
Researchers led from Copenhagen, Denmark, pointed out that lifestyle interventions designed for weight loss have been shown to delay the onset of T2D among high-risk subjects – but the effects of lifestyle factors and obesity on T2D risk might vary between individuals, depending on genetic variation. They analysed a case-cohort sample of 9,556 men and women from the Danish prospective Diet, Cancer and Health cohort, to investigate whether the effects of obesity and unfavourable lifestyle on T2D risk are independent of genetic predisposition.
They defined a favourable lifestyle as having at least three of the following healthy lifestyle factors: no current smoking, moderate alcohol consumption, regular physical activity, and a healthy diet; an unfavourable lifestyle as no or only one healthy lifestyle factor; and the remaining participants were defined as having an intermediate lifestyle. They also assessed genetic risk score (GRS) according to 213 genetic loci robustly associated with T2D, and stratified people’s GRS as low (lowest 25%), intermediate (middle 50%), and high-risk (top 25%) groups.
During an average 12 years’ follow-up, 49.5% of participants developed T2D. The study authors reported that adherence to a favourable lifestyle and normal-weight decreased people’s T2D risk independently of genetic predisposition. Obesity (body mass index BMI ≥30 kg/m2) increased risk of T2D by 5.8-fold compared with non-obesity. However, the independent effects of high (vs. low) genetic risk and unfavourable (vs. favourable) lifestyle were ‘relatively modest’ (hazard ratio, HR = 1.8 and HR = 1.2, respectively), they noted.
The authors concluded: “Individuals with poor lifestyle and obesity are at greater risk of incident T2D regardless of their genetic risk.”
They commented: “The effect of obesity on type 2 diabetes risk is dominant over other risk factors, highlighting the importance of weight management in type 2 diabetes prevention.”
* Jakupović H, Schnurr T, Carrasquilla G, et al. Obesity and unfavourable lifestyle increase type 2 diabetes-risk independent of genetic predisposition. Abstract, poster presentation #376, EASD annual meeting 2019.