Study on the effect of insulin on carbohydrate and lipid metabolism in obese subjects with normal glucose tolerance]

In altogether 32 test persons with normal weight and obese test persons glucose-insulin-tolerance-tests were carried out. In obese persons with normal carbohydrate tolerance -- characterized by 50 g oral glucose tolerance test -- by the decreased glucose assimilation coefficients and the significantly increased level of glycaemia after intravenous application of glucose a disturbance of the glucose-insulin-homoeostasis is already implied. Basal and glucose-stimulated concentrations of IRI in the peripheral venous blood were significantly increased in obese persons. The parameters of lipolysis glycerol and free fatty acids show after a glucose-stimulated insulin excretion and after exogenic insulin application a somewhat retarded decrease in obese persons compared with the control group. In connection with the significantly increased insulin levels in obese persons these findings might refer to a decreased antilipolytic effect of insulin. The two fundamental physiological effects of insulin in the carbohydrate and fat metabolism -- glucose utilization and inhibition of lipolysis -- seem to be distrubed in the same way in obesity.