PLASMA ADRENALINE CONCENTRATION IS LOWER IN POST-OBESE THAN IN NEVER-OBESE WOMEN IN THE BASAL STATE, IN RESPONSE TO SHAM-FEEDING AND AFTER FOOD-INTAKE

1. Plasma pancreatic polypeptide, plasma catecholamine, blood glucose, plasma insulin and plasma peptide YY concentrations were studied to a ssess differences between eight formerly obese and eight never-obese c ontrol women during 25min of sham-feeding (with the sight and smell of an English breakfast) and for 5h after they had ingested the meal (35 14kJ, 50% fat, 35% carbohydrate). The post-obese women had maintained their normal body weight for at least 3 months before the study. 2. Th e plasma noradrenaline concentration was not different between the gro ups either during fasting (post-obese women 0.08 +/- 0.01 ng/ml versus control women 0.10 +/- 0.01 ng/ml) or in the significant postprandial increase (P<0.001). The plasma adrenaline concentration increased sig nificantly during sham-feeding in the control group from 0.024 +/- 0.0 04 ng/ml to 0.033 +/- 0.004 ng/ml (P=0.02) in contrast with the post-o bese women, who had significantly lower plasma concentrations of adren aline in the fasting state (post-obese 0.016 +/- 0.003 ng/ml versus co ntrol women 0.024 +/- 0.004 ng/ml, P=0.003), during sham-feeding (post -obese women 0.018 +/- 0.002 ng/ml versus control women 0.033 +/- 0.00 4 ng/ml, P=0.003) and in the postprandial increase (P=0.003). The maxi mal postprandial response concentrations recorded 5h after the meal we re 0.025 +/- 0.003 ng/ml in post-obese women and 0.035 +/- 0.004 ng/ml in control subjects (P=0.04). There were no significant differences i n plasma pancreatic polypeptide, plasma peptide YY, plasma insulin, or blood glucose concentrations between the two groups. 3. The plasma ad renaline concentration is lower in post-obese women in the basal fasti ng state, during sham-feeding and in response to a meal. These results indicate that post-obese subjects respond differently to food stimula tion than normal subjects.