Comparison of the glucose and insulin responses of horses to 2 formulations of corn syrup.

The objectives of this study were to compare the insulin and glucose responses of horses to 2 formulations of corn syrup, [Karo Light (Karo) available in the United States, and Crown Lily White (Crown), available in Canada]. Horses were evaluated under both fed (n = 14) and fasted (n = 10) conditions. Using a randomized crossover design, each horse underwent an oral sugar test using Karo or Crown syrup. There were no significant differences in insulin or glucose time of maximum concentration (Tmax), maximum concentration (Cmax), or area under the curve (AUC) or in insulin or glucose concentrations at individual timepoints during fed or fasted conditions. Bland-Altman analysis of insulin at 75 minutes indicated a mean bias of 28.7 pmol/L, with 95% limits of agreement from -83.9 to 140.6 pmol/L (fed) and a mean bias of 11.5 pmol/L, with 95% limits of agreement from -78.9 to 101.9 pmol/L (fasted). These findings suggest that Karo and Crown syrup produce similar glucose and insulin responses in horses.