Risk of type 2 diabetes and cumulative excess weight exposure in the Framingham Offspring Study

Aim: Mid-life obesity is associated with T2D risk. However, less is known about the cumulative effect of obesity during adulthood. Methods: Framingham Offspring Study participants who had an examination at 35 +/- 2 years and were initially free of T2D were included in this study (N=1026). A cumulative excess weight (CEW) score (year*kg/m(2)) was calculated until T2D diagnostic or the end of follow-up. Results: Eighty-four individuals (8.2%) developed T2D over 20 +/- 6 years. Mean CEW scores were 118.+/- 114.6 year*kg/m(2) in individuals who developed T2D and 30.2 +/- 91.4 year*kg/m(2) in those who did not develop T2D (P<0.01). T2D risk was doubled for each standard deviation increase in the CEW score (OR=1.99 [1.64-2.40]; P<0.001). However, CEW score was only significantly associated with T2D incidence for participants with a baseline BMI<25 kg/m(2) (OR=2.13 [136-336]; P<0.001). Conclusions: Accumulating weight between the mid-thirties to the mid-fifties increases the risk of developing T2D. However, BMI in mid-thirties remains a stronger predictor of T2D risk. (C) 2013 Elsevier Inc. All rights reserved.