Suppression of insulin secretion by falling plasma glucose levels is impaired in type 2 diabetes.
The ability of Type 2 diabetic patients to suppress islet B-cell secretion in response to falling plasma glucose levels has been studied with two different protocols. (1) Five diet-treated diabetic patients and 6 normal subjects were studied after the termination of a hyperglycaemic clamp at 15 mmol l-1 for 150 min, with the plasma glucose levels then being allowed to fall and the glucose clamp re-established at 10 mmol l-1. The plasma insulin levels fell in normal subjects from 178 +/- 141 (+/- SD) mU l-1 at the end of the 15 mmol l-1 clamp to 147 +/- 97 mU l-1 (p less than 0.02) 20 min later, whereas in diabetic patients there was no significant change from 61 +/- 41 to 56 +/- 35 mU l-1, respectively (NS). (2) The second study was performed to assess the turn-off of islet B-cell secretion with diabetic patients and normal subjects starting at comparable plasma insulin levels. Twelve diet-treated diabetic patients and 11 normal subjects were given a continuous low-dose glucose infusion for 60 min at a rate of 5 mg kg-1 ideal body weight min-1, after which the infusion was turned off and the plasma glucose level allowed to fall.(ABSTRACT TRUNCATED AT 250 WORDS)
Hosker
J P
JP
Diabetes Research Laboratories, Radcliffe Infirmary, Oxford, UK.
Burnett
M A
MA
Matthews
D R
DR
Turner
R C
RC
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D005215:Fasting; D015309:Glucose Clamp Technique; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D008875:Middle Aged; D012016:Reference Values
D001786:Blood Glucose; D007328:Insulin