Hormonal and metabolic parameters following insulin-induced hypoglycemia

The present study was conducted in 12 healthy volunteers to determine the effect of porcine insulin (0.15 U/kg i.v.) on a number of different metabolic and hormonal parameters measured simultaneously. The nadir of blood glucose (19.0 +/- 2.7 ng/100 ml) is detected 30 min following insulin application, paralleled by suppressed levels of FFA and beta-hydroxybutyrate. The lowest level of potassium (3.39 +/- 0.09 mval/l) is observed 45 min following insulin application. The hormones of counterregulation show an uniform pattern of response. Peak levels of norepinephrine (228.9 +/- 36.0 ng/l) and epinephrine (720.6 +/- 125.6 ng/l) are observed at 30 and 45 min, those of cAMP (33.4 +/- 2.5 pmol/ml), glucagon (0.209 +/- 0.024 ng/ml), ACTH (166.0 +/- 40.1 ng/ml), and prolactin (28.1 +/- 7.8 ng/ml) at 45 min and finally those of cortisol (26.1 +/- 3.3 micrograms/100 ml) and growth hormone (21.6 +/- 3.1 ng/ml) at 60 min following insulin injection. As the blood glucose level is already rising after 30 min it is concluded that the catecholamines and glucagon play a major part in the restitution of normal blood glucose levels. At the end of the test, blood glucose and hormone levels have almost normalized, but FFA and beta-hydroxybutyrate levels are doubled and almost triplicated as compared to the starting point levels.