Protein co-ingestion strongly increases postprandial insulin secretion in type 2 diabetes patients

The capacity of nutritional protein to induce endogenous insulin secretion has been well established. However, it is not known whether such a response is applicable in a diverse population of type 2 diabetes patients. The aim of the present study was to assess the impact of co-ingesting either intact or hydrolyzed protein with carbohydrate on postprandial plasma insulin and glucose responses in type 2 diabetes patients. Sixty longstanding, male, type 2 diabetes patients participated in a study in which we determined postprandial plasma insulin and glucose responses after ingesting a single bolus of carbohydrate ( 0.7 g/kg: CHO ) with or without an intact protein ( 0.3 g/kg: PRO ) or its hydrolysate ( 0.3 g/kg: PROh ). Results showed that protein co-ingestion strongly increased postprandial insulin release, with the insulin response +99±41 and +110±10% greater in the CHO+PRO and CHO+PROh experiments when compared with the CHO experiment. The insulinotropic properties of protein co-ingestion were evident in nearly all patients, with 58 out of 60 patients responding > 10% when compared with the insulin response following carbohydrate ingestion only ( CHO ). The concomitant plasma glucose responses were 22±32 and 23±36% lower in the CHO+PRO and CHO+PROh experiments, respectively. We conclude that protein co-ingestion represents an effective dietary strategy to strongly augment postprandial insulin release and attenuate the postprandial rise in glucose concentration in type 2 diabetes patients.