Long-term weight change in adulthood and incident diabetes mellitus: MY Health Up Study

AimTo investigate whether long-term weight/BMI change in adulthood has a significant impact on the incidence of diabetes, independent of attained weight status.MethodsA number of 13,700 participants (2962 men and 10,738 women) aged 36 to 55 years were followed for up to 5 years using data from annual health checkups. Incident cases of diabetes were identified from self-reports or single fasting plasma glucose measurements (≥7.0 mmol/l). Weight/BMI change was calculated from participants’ weight/BMI values at age 20 years and weight/BMI values at a given point during follow-up and used as a time-dependent variable in age-stratified multivariate Cox proportional hazards models.ResultsDuring the 5 year follow-up, 408 participants (137 men and 271 women) developed diabetes. Even after adjusting for BMI during follow-up and other possible confounders, weight/BMI gain since age 20 years was significantly associated with an increased risk of developing diabetes. The hazard ratios were: 2.30 (95% confidence interval (CI): 1.31–4.04) for those who gained 6.0 to <10.0 kg and 3.09 (95% CI: 1.79–5.34) for those who gained ≥10.0 kg [reference: <2.0 kg change]; and 2.61 (95% CI: 1.58–4.31) for those who gained 3.0 to <5.0 kg/m2 and 3.70 (95% CI: 2.22–6.16) for those who gained ≥5.0 kg/m2 [reference: <1.0 kg/m2 change].ConclusionsThe results indicate that long-term weight/BMI gain in adulthood is a significant predictor for the development of diabetes, independent of attained weight status. Because weight gain within the normal weight range could increase the risk of diabetes, non-obese people should also be warned against possible weight gain.