Insulin Requirements in Relation to Insulin Pump Indications in Type 1 Diabetes

Abstract

The purpose of the current research was to assess changes in daily insulin requirements in type 1 diabetic patients transitioning from multiple daily injections (MDI) of insulin to continuous subcutaneous insulin infusion (CSII) using an external insulin pump, according to clinical indications for changing therapy. The charts of 70 patients with type 1 diabetes (T1D) initiating insulin pump therapy were retrospectively reviewed before CSII and after optimization of glycaemic profile with CSII during hospital admission. Daily insulin doses, basal/bolus distributions, dose changes during treatment transition and glycaemic outcomes with MDI and optimized CSII according to insulin pump indications were evaluated. Daily insulin doses were not significantly different among indication groups, with both MDI and CSII; likewise, the overall daily distribution of basal/rapid insulin ratio was similar, around 40/60. With optimized CSII, significant differences were found only in basal/bolus distribution in patients initiating CSII for recurrent hypoglycemia, who had a significantly lower basal (6.4% lower) and a complementary higher bolus requirement, compared to patients initiating CSII for HbA1c ≥ 8.5%. At transition, basal insulin needs declined similarly in the high HbA1c and impractical/inflexible MDI groups by approximately 20%, and up to 30% in the recurrent hypoglycaemia group; bolus doses decreased by 20% when the indication was high HbA1c and by approximately 15% for the other indications. Glycaemic control was significantly improved only in patients initiating CSII for high HbA1c (≥8.5%). Insulin pump indication should be considered when starting T1D patients on CSII. These findings may support clinicians in decision making regarding insulin dose changes when initiating insulin pump therapy.