The effectiveness and durability of an early insulin pump therapy in children and adolescents with type 1 diabetes mellitus

Abstract

Background: This study evaluated the predictors of effectiveness and durability of insulin pump therapy in children and adolescents who have initiated continuous subcutaneous insulin infusion (CSII) within 2 years after the diagnosis of type 1 diabetes mellitus (T1DM).

Subjects and methods: The charts of individuals with T1DM using insulin pumps who were treated at our center were reviewed, including subjects with age at onset of <22 years, interval between onset and insulin pump commencement (interval onset-commencement) of <2 years, use of pumps of >1 year, and use of glucose sensors for <4 weeks/year. The primary end point was the mean glycosylated hemoglobin (HbA1c) value (MHbA1c) throughout the follow-up.

Results: From 684 patients treated with insulin pumps, 119 met the inclusion criteria, and 113 were selected for statistical analysis (60 females; age at diabetes onset, 8.9±5.6 years [mean±SD]; follow-up, 4.0±1.8 years; range, 1-8 years; baseline HbA1c, 9.3±1.8%). Only the interval onset-commencement was a linear predictor of the MHbA1c (P=0.01; R(2)=0.089). A significant reduction of the mean yearly HbA1c from baseline throughout all the follow-up was observed (P<0.001). Categorizing the sample into four quartiles on the basis of an increasing interval onset-commencement resulted in levels of MHbA1c significantly lower in the first and second quartiles in comparison with the fourth quartile (7.6±0.8% and 7.8±1.0%, respectively, versus 8.5±0.8%; P<0.001 and P=0.004, respectively).

Conclusions: The present study suggests that early pump commencement in children and adolescents with T1DM provides lower and more durable HbA1c values than a late commencement. It is possible that an early pump commencement could prolong the honeymoon phase, but we cannot confirm or exclude this hypothesis because the lack of data about C-peptide levels during the follow-up.

FIG. 1.

Linear relationship between the mean glycosylated hemoglobin (MHbA1c) throughout all the follow-up and the interval diabetes onset–pump commencement (expressed as days).

FIG. 2.

Glycosylated hemoglobin (HbA1c) at commencement and mean yearly HbA1c throughout the follow-up (first, second, third, fourth, fifth, sixth, seventh, and eighth years). The bars express the SD; the horizontal lines on the bars express the mean values. All HbA1c values are expressed as percentages. The analysis of variance for repeated measures, limited to the 30 patients who completed the sixth year of follow-up, showed a significant reduction of the HbA1c level from baseline (P<0.001; F=10.86). The comparisons between HbA1c at baseline and the mean yearly HbA1c, from the first until the sixth year (by t test for independent samples) are also shown; comparisons at the seventh and eighth years were not determined (n.d.) because the number of patients was ≤10.

FIG. 3.

Comparison of the mean glycosylated hemoglobin (MHbA1c) throughout all the follow-up of four quartiles obtained dividing the sample on the basis of the interval diabetes onset–pump commencement. The bars express the SD; the horizontal lines on the bars express the mean values. Only those comparisons with significant results (by t test for independent samples, P<0.05) are shown here.

FIG. 4.

Glycosylated hemoglobin (HbA1c) at pump commencement baseline and mean yearly HbA1c of four quartiles obtained dividing the sample on the basis of the interval diabetes onset–pump commencement. The bars express the SD; the horizontal lines on the bars express the mean values. All the HbA1c values are expressed as percentages. Also shown are the comparisons between HbA1c at baseline and the mean yearly HbA1c, from the first until the fourth year (by t test for independent samples); the fifth through eighth years were not considered for statistical analysis because the number of patients was small. By analysis of variance for repeated measures, within-subjects effects: *P<0.001, **P=0.009, ***P<0.001. ^For first versus fourth quartile, by analysis of variance for repeated measures: between-subjects effects, P=0.023, F=5.63; within-subjects effects, P<0.001, F=13.36. ^^For second versus fourth quartile, by analysis of variance for repeated measures: between-subjects effects, P=0.045, F=4.37; within-subjects effects, P=0.001, F=5.15.