Insulin and glucagon responses to adrenaline infusion in abdominal obese men

OBJECTIVE: To investigate the hormonal, cardiovascular and metabolic responses of visceral vs subcutaneous obese men to infused adrenaline. DESIGN: Intervention study of an hour adrenaline infusion (0.01 mu g/kg fat-free mass/min). SUBJECTS: Eighteen moderately obese men (age: 30-40 y, BMI: 28-34 kg/m(2)) divided according to their degree (low vs high) of visceral adipose tissue (AT) accumulation. MEASUREMENTS: Various fatness and fat distribution variables (computed tomography and anthropometry), heart rate and blood pressure, plasma concentrations of gluco-regulatory hormones, glucose, glycerol and free fatty acids (FFA). RESULTS: Similar increases were noted in heart rate, plasma adrenaline, FFA and glycerol levels in both low and high visceral AT groups after hormonal infusion. There was a tendency for plasma glucagon responses to be higher in men with high amounts of visceral fat (p = 0.07). Plasma glucose levels increased in both groups, but significantly more in men with low levels of visceral AT (p < 0.05), whereas plasma insulin concentrations increased significantly only in men with high amounts of visceral AT in response to adrenaline infusion (p < 0.01), In the overall sample of obese men, visceral AT accumulation (but not the fat mass) was positively correlated with plasma insulin (r = 0.70) and glucagon responses (r = 0.63) to the hormone infusion (p < 0.01). These metabolic responses were not related to the achieved catecholamine concentration. CONCLUSION: These results suggest that some of the impairments in plasma glucose-insulin homeostasis noted in visceral obesity may be related to an abnormal metabolic response to an adrenaline challenge.