Glycaemic control in transition-aged versus early adults with type 1 diabetes and the effect of a government-funded insulin pump programme

Aim — To compare glycaemic control and adverse outcomes between transition-aged and early adults with type 1 diabetes, and the impact of continuous subcutaneous insulin infusion (CSII) therapy funded through a government Assisted Devices Program (ADP).

Methods — This retrospective cohort study using healthcare administrative databases from Ontario, Canada included adults aged 18-35 with type 1 diabetes between April 1, 2011 and March 31, 2014. Mean HbA1c was compared between transition-aged (18-24 years) and early adults (25-35 years), overall and stratified by whether or not they received government-funded CSII therapy (CSII vs. non-CSII). Secondary outcomes included rates of hospitalizations/ emergency department visits for hyperglycaemia and hypoglycaemia over a 3-year follow-up. Comparisons were adjusted for relevant covariates.

Results — Among 7,157 participants with type 1 diabetes, mean HbA1c was significantly higher for transition-aged compared to early adults [71 mmol/mol (8.68%) vs. 64 mmol/mol (8.04%), p<0.0001]. This difference was smaller among CSII compared to non-CSII users (p=0.02 for interaction between age group and CSII use). The transition-age group were more likely to experience a hyperglycaemic event compared to early adults (adjusted risk ratio, aRR 1.56, 95% CI 1.25-1.96), which was attenuated by CSII use (aRR 1.13, 95% CI 0.75 – 1.69).

Conclusions — Transition-aged adults with type 1 diabetes had a significantly higher mean HbA1c and risk of hyperglycaemic events compared to early adults. This difference was attenuated for CSII users, indicating that a government-funded CSII program is associated with narrowing of the gap in glycaemic control and associated adverse outcomes for this population.