Missed insulin meal boluses and elevated hemoglobin A1c levels in children receiving insulin pump therapy.

Objective: To identify possible causes of suboptimal glycemic control (ascertained by hemoglobin A1c [HbA1c] level) in youths using insulin pump therapy.

Methods: Forty-eight youths who were receiving insulin pump therapy for > or =6 months, and who were using insulin pumps and blood glucose meters with data that could be downloaded at our facility, are included in this cross-sectional study. Possible causes of suboptimal glycemic control were evaluated by using 4 information sources: 1) insulin pump data downloads; 2) glucose meter data downloads; 3) patient/family questionnaire about insulin bolusing habits, eating habits, exercise, and blood glucose testing habits; and 4) a physician questionnaire. Physicians completed the questionnaire during the patient interview after reviewing the downloaded information and discussing these results with the patient/family.

Results: The mean (+/- standard deviation) age of participants was 15.3 (+/-3.0) years (range: 7-20 years), and the mean (+/- standard deviation) duration of type 1 diabetes and continuous subcutaneous insulin infusion was 8.2 (+/-4.0) and 1.9 (+/-1.0) years, respectively. Patients who missed <1 bolus per week had a mean (95% confidence interval) HbA1c level of 8.0% (7.7, 8.3), whereas those who missed > or =1 mealtime boluses per week had a mean HbA1c level (95% confidence interval) of 8.8% (8.6, 9.1). No significant relationships were found between HbA1c levels in males and females, the amount of exercise per week, or bolusing before insulin pump disconnection for exercise. Although not significant, a trend was found for those who missed <1 bolus per week to perform more blood glucose tests per day and for those who bolused before a meal rather than after to have lower HbA1c levels. Significant correlations were found between HbA1c levels and the number of missed mealtime boluses per week (r =.414) and mean blood glucose levels (r =.70).

Conclusion: Missed mealtime insulin boluses seem to be the major cause of suboptimal glycemic control in youths with diabetes receiving continuous subcutaneous insulin infusion therapy.