Effect of exercise on the pancreatic polypeptide response to food in man

Modest elevations in pancreatic polypeptide (PP) have been observed during exercise while fasting. To determine whether the PP response to a meal is similarly affected by exercise, seven healthy subjects were studied on two occasions. First, the postprandial PP response was determined during rest and then compared to a meal which was subsequently followed by a 45 min period of moderate exercise. Postprandial exercise significantly (P less than 0.01) enhanced the plasma PP response to peak levels of 182 +/- 22 pM versus 85 +/- 22 pM at rest. Concomitantly the plasma glucose fell to a nadir of 84 +/- 4 mg/dl which was significantly (P less than 0.01) below the rest level of 129 +/- 8 mg/dl. Although the rise in PP paralleled the fall in glucose, there was little relationship (r = 0.27) between the incremental changes in these two parameters. Thus, exercise is a natural setting which augments the plasma PP response to a meal. The mechanism may be related to the enhanced cholinergic vagal activity associated with the attendant fall in glycemia.