AIM: This prospective study aimed to identify and estimate the frequency of responders offered Continuous subcutaneous insulin infusion (CSII) from baseline data and during follow-up, and secondly to characterize CSII users with good adherence to pump therapy among 463 children and adolescents with Type 1 diabetes mellitus.

METHODS: A response was defined as lowering HbA1c with 1% or achieving an HbA1c<7.5% (58 mmol/mol). Good adherence was defined as measuring ≥7 self monitored blood glucoses (SMBGs) and taking ≥7 boluses daily. Logistic regression was used to estimate the effect of demographic and clinical variables prior to and during pump treatment.

RESULTS: At 24 months follow-up 32% qualified as responders. Stratifying for age at onset, 45% of the children aged <6 yrs qualified as responders vs. 32% and 28% of the youngsters and adolescents aged 6-12 yrs. and 12-19 yrs., respectively (p=0.02). Responders were characterized by their HbA1c-level at pump onset (p=0.001), taking more daily boluses (7.64 ± 3.33 vs. 6.40 ± 3.18 p=0.003) and measuring more SMBGs per day at follow-up (6.88 ± 2.35 vs. 6.31 ± 2.54 p=0.03). The incidence of severe hypoglycemia decreased from 14.3 to 3.3 events per 100 person years (p<0.0001). Twenty percent did not respond despite a good adherence toward CSII therapy.

CONCLUSION: Age <6 years, high or low HbA1c at pump initiation and number of daily boluses were associated with improved or sustained near-normal metabolic outcome. The incidence of severe hypoglycemia was significantly reduced. Twenty percent of the population had good adherence without any metabolic improvement.