Basal-Bolus Injection vs. Basal-Bolus Insulin Pump in Type 1s

Insulin pump therapy (continuous subcutaneous insulin infusion [CSII]) and multiple daily injections (MDI) with insulin glargine (glargine) as basal insulin and mealtime insulin lispro (lispro) have not been prospectively compared in people naïve to either regimen in a multicenter study.

The study was aimed to help close that deficiency.

People with Type 1 diabetes on NPH-based insulin therapy were randomized to CSII or glargine-based MDI (both otherwise using lispro) and followed for 24 weeks in an equivalence design. Fifty people were correctly randomized and 43 completed the study.

The results showed that total insulin requirement (mean+/-standard deviation [SD]) at endpoint was 36.2+/-11.5 U/day on CSII and 42.6+/-15.5 U/day on MDI. Mean A1c fell similarly in the two groups (CSII -0.7+/-0.7% [+/-SD], MDI -0.6+/-0.8%) with a baseline-adjusted difference of -0.1% (95% CI: -0.5, 0.3). Similarly, fasting blood glucose and other pre-prandial, post-prandial and night-time self-monitored plasma glucose (PG) levels did not differ between the regimens, nor did measures of PG variability.

On CSII, 1,152 hypoglycemia events were recorded by 23 of 28 participants (82%), and 1,022 in the MDI group by 27 of 29 patients (93%; all hypoglycemia differences non-significant).

Treatment satisfaction score increased more with CSII, however, the change in score was similar for the groups. Costs were around 3.9 times higher for CSII.

From the results it was concluded that, in unselected people with Type 1 diabetes naïve to CSII or insulin glargine, glycemic control is no better with the more expensive CSII therapy compared to glargine-based MDI therapy.

Diabetes Care. 2009 Apr 23