The effects of initial and subsequent adiposity status on diabetes mellitus.

Background: Obesity in adulthood is associated with increased risk for diabetes mellitus (DM). It is uncertain whether this risk is attenuated in adulthood who are overweight or obese initially but not obese subsequently.

Methods And Results: The data were collected in 1992 and then again in 2007 from the same group of 687 participants (male: 58.1%, age: 48.1 ± 6.2 years).The participants were categorized into four groups on the basis of adiposity status in 1992 and 2007: group I included subjects with a normal BMI in 1992 and 2007; group II, those with a normal BMI in 1992 who were overweight or obese in 2007; group III, those who were overweight or obese in 1992 but normal BMI in 2007; and group IV, those who were overweight or obese in 1992 and 2007. With group I as reference, the HR is 0.818 for group II (95% CI: 0.341-1.962, p=0.653), 2.231 for group III (95% CI: 1.087-4.579, p=0.029) and 1.855 for group IV (95% CI: 1.049-3.279, p=0.034) after adjustment for confounders. It was not significantly different between groups I and II, as well as between groups III and IV.

Conclusion: In adulthood, becoming nonobese could not reverse the adverse effects of obesity on DM, as compared with the subjects who persist being overweight or obese. Keeping weight in the normal BMI range should be emphasized in the public for preventing DM.