Hyperglycemia abolishes meal-induced satiety by a dysregulation of ghrelin and peptide YY3-36 in healthy overweight/obese humans

Satiety and satiety- regulating gut hormone levels are abnormal in hyperglycemic individuals. We aimed to determine whether these abnormalities are secondary to hyperglycemia. Ten healthy overweight/obese subjects (age: 56 +/- 3 yr; BMI: 30.3 +/- 1.2 kg/m(2)) received three equicaloric meals at t = 0, 4, and 8 h in the absence (control trial) and presence of experimental hyperglycemia (hyperglycemia trial; 5.4 mM above basal). Circulating levels of glucose, insulin, ghrelin, and peptide YY (PYY)(3-36) and visual analog scale ratings of satiety were measured throughout each trial. In the control trial, glucose, insulin, PYY3-36, and the feeling of fullness were increased in the postprandial periods, whereas ghrelin was decreased. In the hyperglycemia trial, in which plasma glucose was increased to 11.2 +/- 0.1 mmol/l, postprandial meal responses (AUC: 0-2, 4-6, and 8-10 h) of PYY3-36 were lower (meal 1, P < 0.0001; meal 2, P < 0.001; meal 3, P < 0.05), whereas insulin (meal 1, P < 0.01; meal 2, P < 0.001; meal 3, P < 0.05) and ghrelin (meal 1, P < 0.05; meal 2, P < 0.05; meal 3, P < 0.05) were higher compared with the control trial. Furthermore, the incremental (Delta 0-0.5, 4-4.5, and 8-8.5 h) ghrelin response to the first and third meals was higher in the hyperglycemia trial in contrast to control (Delta : 2.3 +/- 8.0, P = 0.05; Delta : 14.4 +/- 2.5, P < 0.05). Also, meal-induced fullness was prevented (meal 1, P = 0.06; meal 2, P < 0.01; meal 3, P = 0.08) by experimental hyperglycemia. Furthermore, trends in ghrelin, PYY3-36, and fullness were described by different polynomial functions between the trials. In conclusion, hyperglycemia abolishes meal-induced satiety and dysregulates postprandial responses of the gut hormones PYY3-36 and ghrelin in overweight/obese healthy humans.