Abstract

Background: Much uncertainty exists about the role of dietary glycemic index and glycemic load in the development of type 2 diabetes mellitus, especially in populations that traditionally subsist on a diet high in carbohydrates. Methods:We observed a cohort of 64 227 Chinese women with no history of diabetes or other chronic disease at baseline for 4.6 years.In-person interviews were conducted to collect data on dietary habits, physical activity, and other relevant information using a validated questionnaire.Incident diabetes cases were identified via in-person follow-up.Associations between dietary carbohydrate intake, glycemic index, and glycemic load and diabetes incidence were evaluated using multivariable Cox proportional hazards models. Results:We identified 1608 incident cases of type 2 diabetes mellitus in 297 755 person-years of follow-up.Di-etary carbohydrate intake and consumption of rice were positively associated with risk of developing type 2 diabetes mellitus.The multivariable-adjusted estimates of relative risk comparing the highest vs the lowest quintiles of intake were 1.28 (95% confidence interval, 1.09-1.50)for carbohydrates and 1.78 (95% confidence interval, 1.48-2.15)for rice.The relative risk for increasing quintiles of intake was 1.00, 1.04, 1.02, 1.09, and 1.21 (95% confidence interval, 1.03-1.43)for dietary glycemic index and 1.00, 1.06, 0.97, 1.23, and 1.34 (95% confidence interval, 1.13-1.58)for dietary glycemic load. Conclusion:High intake of foods with a high glycemic index and glycemic load, especially rice, the main carbohydrate-contributing food in this population, may increase the risk of type 2 diabetes mellitus in Chinese women.