• diabetes;
  • family history;
  • genetics;
  • insulin resistance;
  • insulin secretion;
  • obesity



The aim of this study was to characterize diabetes risk in relation to amount and distribution of body fat (environmental factors) and genetic risk defined as having first-degree (FH1) or second-degree relatives with diabetes.


We analysed the METSIM population of 10 197 middle-aged, randomly selected men. At baseline, information about family history of diabetes was registered and all individuals underwent extensive phenotyping. A follow-up study was conducted after 6 years. The metabolic consequences of increased visceral versus subcutaneous fat were characterized in a separate cohort of 158 healthy men (the Kuopio Cohort of the EUGENE2 study).


At baseline, individuals with a family history of diabetes (FH+) had approximately a twofold increase in the prevalence of type 2 diabetes compared with individuals without a family history of the disease (FH−) (18.0% vs. 9.9%; = 1.3 × 10−31). FH1 individuals were more commonly overweight and obese compared with FH− (69.2% vs. 64.8%; = 1.3 × 10−4) and, for a given body mass index, showed an increased risk profile for both type 2 diabetes and cardiovascular disease as well as a greater susceptibility to the negative consequences of increased body fat also when nonobese. Subgroup analyses indicated that the metabolic consequences were due primarily to increased ectopic/visceral fat rather than subcutaneous fat. The increased risk profile in FH+ individuals was not altered by adjusting for 43 major diabetes risk genes.


Family history of type 2 diabetes (particularly FH1) is associated with both increased risk of becoming overweight/obese and with a greater susceptibility to the negative consequences of increasing body fat, probably as a consequence of an increased propensity to accumulate ectopic (nonsubcutaneous) fat.