Obesity increases diabetes risk significantly regardless of genetic predisposition

Researchers at University of Copenhagen, Denmark have found that having normal body weight is crucial in the prevention of type 2 diabetes, regardless of genetic predisposition.Obesity increases the risk of developing type 2 diabetes by at least 6 times, regardless of genetic predisposition to the disease.The new research has been published in Diabetologia .

Using data from a case-cohort study nested within the Diet, Cancer and Health cohort in Denmark, the authors examined the joint association of obesity, genetic predisposition, and unfavourable lifestyle with incident type 2 diabetes (T2D). The study sample included 4,729 individuals who developed type 2 diabetes during a median 14.7 years of follow-up, and a randomly selected cohort sample of 5,402 individuals (the control group).

The mean age of all participants was 56.1 years (range 50-65) and 49.6% were women. Overall, 21.8% of all participants were classified as obese, 43.0% as overweight and 35.2% as having normal weight; and 40.0% of the participants had a favourable lifestyle, 34.6% had an intermediate lifestyle and 25.4% had an unfavourable lifestyle.

Genetic predisposition was quantified using a genetic risk score (GRS) comprising 193 known type 2 diabetes-associated genetic variants and divided into 5 risk groups of 20% each (quintiles), from lowest (quintile 1) to highest (quintile 5) genetic risk. Lifestyle was assessed by a lifestyle score composed of smoking, alcohol consumption, physical activity and diet. Statistical modelling was used to calculate the individual and combined associations of the GRS, obesity and lifestyle score with developing T2D.