Wu, TianyingGiovannucci, EdwardPischon, TobiasHankinson, SusanMa, JingRifai, NaderRimm, Eric Bruce::0ab2926c8242f35e5a982e3cf59f4987::6002019-08-262004Wu, Tianying, Edward Giovannucci, Tobias Pischon, Susan E Hankinson, Jing Ma, Nader Rifai, and Eric B Rimm. 2004. “Fructose, Glycemic Load, and Quantity and Quality of Carbohydrate in Relation to Plasma C-Peptide Concentrations in US Women.” The American Journal of Clinical Nutrition 80 (4): 1043–49. https://doi.org/10.1093/ajcn/80.4.1043.0002-91651938-3207http://nrs.harvard.edu/urn-3:HUL.InstRepos:41249132Background: Circulating C-peptide concentrations are associated with insulin resistance and the development of type 2 diabetes. However, associations between fructose and the quantity and quality of total carbohydrate intake in relation to C-peptide concentrations have not been adequately examined. Objective: We assessed the association of dietary fructose, glycemic load, and carbohydrate intake with fasting C-peptide concentrations. Design: Plasma C-peptide concentrations were measured in a cross-sectional setting in 1999 healthy women from the Nurses' Health Study I and II. Dietary fructose, glycemic load, and carbohydrate intake were assessed with the use of semiquantitative food-frequency questionnaires. Results: After multivariate adjustment, subjects in the highest quintile of energy-adjusted fructose intake had 13.9% higher C-peptide concentrations (P for trend = 0.01) than did subjects in the lowest quintile. Similarly, in the multivariate model, subjects in the highest quintile of glycemic load had 14.1% (P for trend = 0.09) and 16.1% (P for trend = 0.04) higher C-peptide concentrations than did subjects in the lowest quintile after further adjustment for total fat or carbohydrate intake, respectively. In contrast, subjects with high intakes of cereal fiber had 15.6% lower (P for trend = 0.03) C-peptide concentrations after control for other covariates. Conclusions: Our results suggest that high intakes of fructose and high glycemic foods are associated with higher C-peptide concentrations, whereas consumption of carbohydrates high in fiber, such as whole-grain foods, is associated with lower C-peptide concentrations. Furthermore, our study suggests that these nutrients play divergent roles in the development of insulin resistance and type 2 diabetes.en-USJournal Article2019-08-2610.1093/ajcn/80.4.1043