Timing of bolus in children with type 1 diabetes using continuous subcutaneous insulin infusion (TiBoDi Study).

Continuous subcutaneous insulin infusion is considered a safe and effective way to administer insulin in pediatric patients with type 1 diabetes, but achieving satisfactory and stable glycemic control is difficult. Several factors contribute to control, including fine-tuning the basal infusion rate and bolus timing. We evaluated the most effective timing of a pump-delivered, preprandial bolus in children with type 1 diabetes. We assessed the response of 30 children with type 1 diabetes to a standard meal after different timing of a bolus dose. The glucose levels for 3 h after the meal were lower (i.e., closer to the therapeutic target of <140 mg/dL) when the bolus doses were administered 15 min or immediately before the meal, rather than after the meal. However, these differences were not statistically significant, except at the 1-h postprandial time point: bolus just after meal, 177 +/- 71 mg/dL (9.83 +/- 3.94 mmol/L); 15 min before meal, 136 +/- 52 mg/dL (7.55 +/- 2.89 mmol/L) (P = 0.044); and just before meal, 130 +/- 54 mg/dL (7.22 +/- 3.00 mmol/L) (P = 0.024). The area under the curve (AUC) (in mg/min) did not differ significantly with different bolus times, but the SD of the AUC was the lowest with the bolus given 15 min before the meal. These data support injection of the bolus before, rather than after, eating, even if the patient is hypoglycemic before meals.