BARCELONA – Obesity, more so than having a poor lifestyle, significantly raised the odds of developing type 2 diabetes, independent of individuals’ genetic susceptibility, according to data from a Danish population-based, case-cohort study.
In fact, having a body mass index (BMI) of more than 30 kg/m2 was linked with a 480% risk of incident type 2 diabetes, compared with being of normal weight (BMI, 18.5-24.9 kg/m2). The 95% confidence interval was 5.16-6.55. Being overweight (BMI, 25-29.9 kg/m2) also carried a 100% increased risk of type 2 diabetes (hazard ratio, 2.37; 95% CI, 2.15-2.62).
Having an unfavorable lifestyle – which was defined as having no or only one of several healthy-living characteristics, from not smoking and moderating alcohol use to eating a well-balanced, nutritious diet and exercising regularly – increased the risk of diabetes by 18%, compared with having a favorable lifestyle (HR, 1.18; 95% CI, 1.06-1.30).
Individuals with a high genetic risk score (GRS) had a 100% increased risk of developing the disease versus those with a low GRS (HR, 2.0; 95% CI, 1.1-1.3).
“High genetic risk, obesity, and [an] unfavorable lifestyle increase the individual-level risk of incident type 2 diabetes,”and associates reported in a poster presentation at the annual meeting of the European Association for the Study of Diabetes. Their results suggest that “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.”
Ms. Jakupovic, a PhD student at theat the University of Copenhagen, and coauthors examined data on 9,555 participants of the Diet, Cancer, and Health cohort, a large, prospective study that has been running since the early 1990s.
Around half of the study sample were women and the mean age was 52 years. Just over one-fifth (22.8%) were obese, 43% were overweight, and the remaining 35.2% were of normal weight. A quarter (25.4%) had an unfavorable lifestyle, 40% a favorable lifestyle, and the remainder an “intermediate” lifestyle. Over a follow-up of almost 15 years, nearly half (49.5%) developed type 2 diabetes.
Genetic risk was assessed by a GRS comprising 193 genetic variants known to be strongly associated with type 2 diabetes, Ms. Jakupovic explained, adding that, using the GRS, patients were categorized into being at low (the lowest 20%), intermediate (middle 60%) and high risk (top 20%) of type 2 diabetes.
Considering individuals’ GRS and lifestyle score together showed an increasing risk of developing type 2 diabetes from the low GRS/favorable-lifestyle category (HR, 1.0; reference) upward to the high GRS/unfavorable lifestyle (HR, 2.22; 95% CI, 1.76-2.81).
The Diet, Cancer, and Health cohort is supported by the Danish Cancer Society. The Novo Nordisk Foundation Center for Basic Metabolic Research is an independent research center at the University of Copenhagen partially funded by an unrestricted donation from the Novo Nordisk Foundation. Ms. Jakupovic and associates are funded either directly or indirectly by the Novo Nordisk Foundation.
SOURCE: Jakupovic H et al. EASD 2019,