The Carbohydrate Counting in Adolescents With Type 1 Diabetes (CCAT)Study

Abstract

This article reports pilot study results evaluating the accuracy of carbohydrate counting among adolescents with type 1 diabetes. This cross-sectional observational study included 48 adolescents ages 12–18 years (mean 15.2 ± 1.8 years) with type 1 diabetes of > 1 year in duration (mean A1C 8.0 ± 1.0%) who used insulin:carbohydrate (I:C)ratios for at least one meal per day. The adolescents were asked to assess the amount of carbohydrate in 32 foods commonly consumed by youths. Foods were presented either as food models or as actual food, with some items presented as standard serving sizes and some self-served by study participants. T-tests were used to assess the significance of over- or underestimation of carbohydrate content. For each meal, accuracy was categorized as accurate (within 10 grams), overestimated (by > 10 grams),or underestimated (by > 10 grams) based on the commonly used I:C ratio of 1 unit of insulin per 10 grams of carbohydrate. Only 23% of adolescents estimated daily carbohydrate within 10 grams of the true amount despite selection of common meals. For dinner meals, individuals with accurate estimation of carbohydrate grams had the lowest A1C values (7.69± 0.82%, P = 0.04). The pilot study provides preliminary evidence that adolescents with type 1 diabetes do not accurately count carbohydrates. Further data are needed on carbohydrate counting accuracy and other factors that affect glycemic control.