Endocrine Abstracts

Background and aim: Insulin resistance is associated with type 2 diabetes and obesity but recent studies suggest that it may also be associated with type 1 diabetes (T1D), which may affect glycemic control. Hypoglycemia is a dreaded condition among patients with T1D and may also limit optimal glycemic management. We aimed to investigate insulin sensitivity and metabolic adaptions in healthy control subjects and T1D subjects.

Material and methods: We used a randomized crossover design to investigate nine normal weight men with T1D and nine age, BMI and gender comparable healthy control subjects. All subjects were investigated on two separate occasions only differing in regards to the intervention: 1) one episode of hypoglycemia (Single hypo-day) and 2) two consecutive episodes of hypoglycaemia (Dual hypo-day). Both study days included ahyperinsulinemic euglycemic glucose clamp and blood samples were obtained consecutively throughout the day.

Results: Glucose infusion rate (GIR) was significantly (P=0.001) lower in the T1D subjects (≈ 5.7 mg/kg per min) compared to the control subjects (≈ 7.6 mg/kg per min) with no significant effect of single/dual hypoglycemia events (P>0.05). During hypoglycemia, plasma glucose levels reached a comparable nadir of ~2.55 mmol/L within interventions and groups. The T1D subjects had lower increments in glucagon and adrenaline compared with healthy controls (P<0.05) without any difference as regards to the interventions (P>0.05).

Conclusion: Subjects with T1D were more insulin resistant and had inferior increments in counter regulatory hormones during hypoglycemia compared with control subjects. A preceding hypoglycemic event the day before did not affect these findings. These results indicate that insulin resistance in present in normal weight T1D subjects and confirm that T1D subjects have defective counter regulatory response to hypoglycemia