Carbohydrate score and rice intake for breakfast, lunch, and dinner and impaired glucose metabolism in a working population: A cross-sectional study.

Abstract

Few studies have examined the association between carbohydrate intake and diabetes with consideration to time of eating. We investigated the association of carbohydrate score and rice intake for breakfast, lunch, and dinner with impaired glucose metabolism in a Japanese working population. Participants were 1416 workers (aged 18-69 years) without a history of diabetes or serious disease who participated in a health survey. Intakes of rice, bread, and noodles at each meal were ascertained using a questionnaire, and carbohydrate score was calculated from these intakes. Impaired glucose metabolism was defined by fasting blood glucose ≥110mg/dl or HbA1c≥6.0% Logistic regression analysis was used to estimate the odds ratios of impaired glucose metabolism for quartile of carbohydrate score or rice intake for each meal with adjustment for covariates. Carbohydrate score and rice intake for each meal were not significantly associated with impaired glucose metabolism. However, among non-obese participants (BMI <25kg/m2), a higher intake of rice at dinner was associated with an increased odds of having impaired glucose metabolism (P for trend=0.02), with a multivariable-adjusted odds ratio for the highest versus lowest quartile of rice intake at dinner of 3.43 (95% confidence interval 1.22-9.70). In contrast, no such association was observed among obese participants (BMI ≥25kg/m2) (P for interaction=0.097). Our results suggest that carbohydrate score and rice intake for each meal are not associated with impaired glucose metabolism. The increased odds of having impaired glucose metabolism associated with higher rice intake at dinner among non-obese participants requires further investigation.