"BackgroundIntensive treatment to achieve good glycaemic control in diabetic patients is limited by a high frequency of hypoglycaemia. The glucose concentrations at which symptoms and release of counter-regulatory hormones takes place have not been studied in patients with well controlled type-2 diabetes.
MethodsWe studied seven well controlled, non-insulin treated, type-2 diabetic patients (mean HbA1 [corrected according to Diabetes Control and Complications Trial] 7·4%, SD 1·0) and seven healthy controls matched for age, sex, and body mass index with a stepped hyperinsulinaemic hypoglycaemic glucose clamp. Symptoms, cognitive function, and counter-regulatory hormone concentrations were measured at each glucose plateau, and the glucose value at which there was a significant change from baseline was calculated.
FindingsSymptom response took place at higher whole-blood glucose concentrations in diabetic patients than in controls. Counter-regulatory release of epinephrine, norepinephrine, growth hormone, and cortisol showed a similar pattern—eg, at blood glucose concentrations of 3·8 mmol/L [SD 0·4] vs 2·6 [0·3] for epinephrine.
InterpretationGlucose thresholds for counter-regulatory hormone secretion are altered in well controlled type-2 diabetic patients, so that both symptoms and counter-regulatory hormone release can take place at normal glucose values. This effect might protect type-2 diabetic patients against episodes of profound hypoglycaemia and make the achievement of normoglycaemia more challenging in clinical practice."
What the above study shows is that, in people with "well controlled" T2DM (mean HbA1c 7·4%, SD 1·0 is poor control. Less than 6% is good control), there is counter-regulatory release of adrenaline, noradrenaline, growth hormone and cortisol at normal blood glucose levels. This is bad, as it's unhealthy to have release of counter-regulatory hormones under normal living conditions.
EDIT: Graham posted this study in support of his belief that there is low/no cortisol etc secretion due to blood glucose not falling low enough. This study actually counters his belief, as blood glucose doesn't fall low enough due to excessive cortisol etc secretion!