Missed bolus doses: devastating for metabolic control in CSII-treated adolescents with type 1 diabetes

To investigate the management of continuous subcutaneous insulin infusion (CSII) in adolescents with type 1 diabetes including their administration of bolus doses and to study relationships between insulin omission and metabolic control, body mass index, daily frequency of self-monitoring of blood glucose (SMBG) and bolus doses, health-related quality of life (HRQOL), the burden of diabetes and treatment satisfaction.

Ninety CSII-treated (> or =6 months) adolescents aged 12-18 yr, from four diabetes clinics in Sweden, participated in the study. The adolescents recorded their meal intake the previous day, which was compared with downloaded pump data, and the frequency of missed boluses was stated. Haemoglobin A1c (HbA1c) and diabetes-related data were recorded. HRQOL and treatment satisfaction were measured with questionnaires.

Thirty-eight per cent of the adolescents had missed >15% of the doses the previous day, those had higher HbA1c (7.8 +/- 1.0 vs. 7.0 +/- 1.2%, p = 0.001), took fewer daily boluses (3.8 +/- 1.7 vs. 5.3 +/- 1.7, p < 0.001) and SMBG (2.4 +/- 1.8 vs. 3.6 +/- 1.8, p = 0.003), were less satisfied with their treatment (4.8 vs. 5.3, scale 0-6, p = 0.029) and perceived the medical treatment more negatively (72.1 vs. 79.7, scale 0-100, p = 0.029). Multiple linear regression analysis showed that the variations in HbA1c could be explained by the frequency of bolus doses (p = 0.013) and SMBG per day (p < 0.0001) adjusted for duration and age (r(2) = 0.339, p < 0.0001).

Insulin omission was common. Those who missed doses were less satisfied and perceived more impact with the treatment. The frequencies of daily boluses and SMBG were associated with metabolic control. Diabetes teams need strategies to guide adolescents on how to avoid insulin omission.