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 A(1c) [HbA(1c)] level) in youths using insulin pump therapy. Methods. Forty-eight youths who were receiving insulin pump therapy for greater than or equal to6 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 >= 1 mealtime boluses per week had a mean HbA(1c) 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.