Patients with type 1 diabetes adapt acutely to sustained mild hypoglycaemia.
The relationship between awareness of, and the catecholamine response to, sustained mild hypoglycaemia was examined in six well-controlled Type 1 diabetic patients (age 24-41 years, HbA1 less than 10.0%) using a hyperinsulinaemic clamp. Blood glucose was maintained at 2.8 mmol l-1 for 90 min with a euglycaemic (4.5 mmol l-1) clamp as a control. After 40 min at a blood glucose of 2.8 mmol l-1, symptom score had increased from 0.2 +/- 0.2 (+/- SE) to 3.0 +/- 0.8 (p less than 0.01), cognitive function (measured by reaction time) deteriorated by 55 +/- 20 ms, and four patients 'felt hypoglycaemic'. This was associated with a rise in plasma adrenaline from 0.48 to 1.30 nmol l-1 (p less than 0.01). However when hypoglycaemia was prolonged to 90 min, symptom score decreased to 1.8 +/- 0.2, none 'felt hypoglycaemic', and reaction time improved by 30 +/- 12 ms, despite a progressive rise in plasma adrenaline to 1.62 nmol l-1. Thus, despite high levels of adrenaline, diabetic patients develop reduced symptoms and no longer 'feel hypoglycaemic' during sustained mild hypoglycaemia.
Kerr
D
D
Department of Medicine, University Hospital, Nottingham, UK.
Macdonald
I A
IA
Tattersall
R B
RB
D000064:Acclimatization; D000328:Adult; D001364:Awareness; D001786:Blood Glucose / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D004837:Epinephrine / Q000097:blood; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000503:physiopathology*; D007332:Insulin Infusion Systems; D008297:Male; D009638:Norepinephrine / Q000097:blood; D011930:Reaction Time; D014202:Tremor / Q000209:etiology
D001786:Blood Glucose; D009638:Norepinephrine; D004837:Epinephrine