Prospective study of dietary carbohydrates, glycemic index, glycemic load, and incidence of type 2 diabetes mellitus in middle-aged Chinese women.
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 1,608 incident cases of type 2 diabetes mellitus in 297,755 person-years of follow-up. Dietary 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.


CONCLUSIONS
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.
Villegas
Raquel
R
Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt University Medical Center, 2525 West End Ave, Ste 600, Nashville, TN 37203-1738, USA.
Liu
Simin
S
Gao
Yu-Tang
YT
Yang
Gong
G
Li
Honglan
H
Zheng
Wei
W
Shu
Xiao Ou
XO
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D003625:Data Collection / Q000379:methods / Q000706:statistics & numerical data; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology*; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D038321:Glycemic Index; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D015999:Multivariate Analysis; D012275:Oryza / Q000737:chemistry; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013997:Time Factors
D001786:Blood Glucose; D004040:Dietary Carbohydrates