Background and Aims: To evaluate the metabolic effect of Continuous Subcutaneous Insulin Infusion (CSII) therapy, measured by changes in HbA1c levels during the first year of implementation, in a cohort of paediatric patients with Type 1 Diabetes Mellitus (T1DM) at St Mary’s Hospital, London. Secondary aims were to compare this effect to a control group on a basal–bolus (BB) regimen, and to assess whether any change in HbA1c was sustained over a five-year period.
Method: Retrospective data was collected from 40 paediatric T1DM patients treated with CSII therapy and 40 patients on BB therapy as controls, between January 2010 and May 2020. Median HbA1c levels from the year prior to starting CSII were compared with those from each of the five subsequent years. Data was collected over a six-year period.
Results: In the first year following CSII initiation, the median HbA1c decreased by 7.25 mmol/mol, from 72.25 mmol/mol to 65 mmol/mol. In contrast, the BB group experienced a median increase in HbA1c of 1.75 mmol/mol over the same period. This is a statistically significant difference (p<0.0001) in the two therapies. However, the initial improvement in the CSII group diminished over time; by year five, HbA1c had increased to 73.25 mmol/mol, surpassing baseline levels by 1 mmol/mol.
Conclusion: CSII therapy was associated with a significant short-term improvement in glycaemic control compared to BB therapy. However, this metabolic benefit was not sustained, with HbA1c levels returning to—and eventually exceeding—baseline levels after five years.
