Insulin pulsatility after the intravenous glucose bolus

Abstract

OBJECTIVE: The aim of the study was to assess whether sudden change in blood glucose concentration in healthy subject would produce insulin secretory pattern similar to one in type 2 diabetic subjects (T2D). DESIGN: The concept of the study was to 'reset' the pancreas and empty the stored insulin pool, so that subtle derangements of the pulsatile insulin secretion could be studied. METHODS: The study group included 6 control and 7 T2D subjects. For insulin and glucose determination, blood was sampled for 60 minutes with 2 minutes inter-sample interval. To increase blood glucose an intravenous glucose bolus was given (0.3 g/kg body weight). RESULTS: The average glucose level in the T2D group was significantly higher, but the average insulin concentration was not different between the groups. Insulin half-life, pulse amplitude, number of pulses and interpulse interval did not differ between the groups. CONCLUSIONS: Therefore, the sudden increase in blood glucose causes insulin secretory pattern to become similar in the healthy and in the T2D subjects. However, the defect in the insulin secretion or glucose sensing inherent to β-cell exists, as the insufficient quantity of insulin is secreted in response to the increased glucose level.

Keywords

• insulin
• type ii diabetes mellitus
• pulsatile secretion