Abstract P189: Optimal Measures of Carbohydrate Quality to Reduce the Risk of Type 2 Diabetes

Introduction: A plethora of indices have been investigated as optimal measures of carbohydrate quality in relation to risk of type 2 diabetes (T2D), but a systematic comparison has not been conducted. Hypothesis: We hypothesized that not all carbohydrate quality indices are equally associated with the risk of T2D. Methods: We investigated associations between twenty-two carbohydrate quality variables and T2D risk among 212,883 US adults with up to 32y of follow-up in the ongoing Nurses’ Health Study (NHS), NHS II, and the Health Professionals Follow-up Study. We used multivariable and BMI-adjusted Cox proportional hazards regression models. Results: Cereal fiber (comparing extreme quintiles of intake, RR:0.82, 95% CI:0.78, 0.87), whole fruit carbohydrates (RR:0.82, 95% CI:0.78, 0.87), glycemic index (RR:1.18, 95% CI:1.12, 1.24), and sugar-sweetened beverage (SSB) sugar (RR:1.23, 95% CI:1.17, 1.29) had the largest observed risk estimates of T2D (all P-trend<0.001). In addition, dietary glycemic load, starch, starchy vegetables, and potato and legume carbohydrates were positively associated (RR’s= 1.07 - 1.14), while whole grain carbohydrate intake was inversely associated with risk of T2D (RR= 0.94). Total and refined grain carbohydrates, added sugar, and non-starchy vegetables were not associated with risk of T2D. Ratios of carbohydrate or starch to total fiber or cereal fiber were all positively associated with risk of T2D (RR’s=1.11 - 1.33). The alternate Carbohydrate Quality Index (aCQI) (RR:0.73, 95% CI:0.69, 0.77) was more strongly associated with risk of T2D than the original CQI (RR:0.90, 95% CI:0.85, 0.95; both P-trend<0.001). Conclusion: Although many indices were associated with risk of T2D, higher intakes of cereal fiber and whole fruit carbohydrates, and lower intakes of glycemic index and sugar-sweetened beverage sugar had the lowest risk of T2D. The aCQI, comprising these four dietary variables and whole-grain carbohydrates, was strongly associated with risk of T2D and warrants further investigation.