Effect of obesity and weight loss on the arginine vasopressin response to insulin-induced hypoglycaemia.
Arginine vasopressin (AVP) response to insulin-induced hypoglycaemia was evaluated in 16 men with normal weight and in 9 obese men. Obese subjects were restudied following substantial weight loss. The decrease in blood glucose concentrations after insulin injection (0.15 U/kg i.v. bolus) had a similar pattern and magnitude in the normal controls and in the obese subjects both before and after weight loss. Basal plasma insulin concentrations in the obese patients were significantly higher than in the normal weight subjects, but were back to normal after weight reduction. During all tests, blood osmolality, haematocrit and blood pressure remained constant. The AVP rise during the insulin tolerance test (ITT) was significantly lower in the obese patients than in the normal controls. The mean peak plasma AVP level was 2.3 times higher than the basal value in the normal controls, but only 1.6 times in the obese patients. After weight loss, the obese men regained normal AVP responses during the ITT. These data indicate that a hypothalamic pituitary disorder affects the AVP response to insulin-induced hypoglycaemia in obese men.
Coiro
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Cattedra di Clinica Medica Generale, University of Parma, Italy.
Chiodera
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P
D000328:Adult; D001127:Arginine Vasopressin / Q000097:blood*; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007003:Hypoglycemia / Q000097:blood* / Q000139:chemically induced; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D009765:Obesity / Q000503:physiopathology*
D001786:Blood Glucose; D007328:Insulin; D001127:Arginine Vasopressin; D006854:Hydrocortisone