Postprandial metabolic responses to mixed versus liquid meal tests in healthy men and men with type 2 diabetes

Abstract Aims Compare metabolic responses after mixed versus liquid meals of similar caloric/nutritional content in healthy and type 2 diabetes (T2D) subjects. Methods Ten healthy men and 10 men with T2D received mixed and liquid meals after an overnight fast. Classical (insulinogenic index; insulin/glucose areas under curves, AUCinsulin /AUCglucose ) and model-based (beta-cell glucose sensitivity; rate sensitivity; potentiation factor ratio, PFR) beta-cell function estimates were calculated. Between-meal differences in glucose, insulin, C-peptide, triglyceride (TG), beta-cell function and oral glucose insulin sensitivity (OGIS) and between-meal correlations for beta-cell function and OGIS were evaluated. Results Among healthy subjects, beta-cell function and OGIS were similar between meals. C-peptide ( p = 0.03), insulin ( p = 0.002), AUCinsulin /AUCglucose ( p = 0.004) and insulin secretion ( p = 0.04) were higher after the liquid meal. Among T2D subjects, glucose, insulin, C-peptide, beta-cell function, and OGIS were similar. PFR was higher ( p = 0.004) and TG increased more slowly ( p = 0.002) after the liquid meal. OGIS and beta-cell function were correlated during both meals in both groups ( r = 0.66–0.98), except incremental AUCinsulin /AUCglucose , rate sensitivity, and, in healthy subjects, PFR. Conclusions Metabolic responses after mixed or liquid meals of similar content were highly correlated in T2D and healthy subjects. In T2D, the liquid meal produced beta-cell function estimates generally similar to the mixed meal.