Evaluating the effects of HCL insulin pumps on weight and glycaemic control in type 1 diabetes: a retrospective multi-centre study

Eoghan Carey; Caoimhe Kalnoki; Isabelle Allen; David Slattery; Patrick Divilly; Wan Aizad Wan Mahmood; Ronan Canavan

doi:10.1530/endoabs.115.P33

P33

Prev Next

Section Contents Cite

Endocrine Abstracts (2026) 115 P33 | DOI: 10.1530/endoabs.115.P33

IES2025 Research, Audit and Quality Improvement Projects Physical Posters (55 abstracts)

Evaluating the effects of HCL insulin pumps on weight and glycaemic control in type 1 diabetes: a retrospective multi-centre study

Eoghan Carey ¹ , Caoimhe Kalnoki ¹ , Isabelle Allen ² , David Slattery ¹ , Patrick Divilly ¹ , Wan Aizad Wan Mahmood ² & Ronan Canavan ²

Author affiliations

¹St Vincent’s University Hospital, Dublin, Ireland; ²St Columcille’s Hospital, Dublin, Ireland

Hybrid Closed Loop (HCL) Insulin Pumps are increasingly standard in healthcare systems for managing Type 1 Diabetes (T1D), offering improved glucose control, safety, and patient satisfaction. We assessed the impact of HCL pumps on HbA1c, weight, Time-in-Range (TIR), and hypoglycaemia (<4 mmol/l) through a retrospective review of 317 T1D patients from two clinics in Dublin. Independent variables included age, gender, pump type, and prior pump use; dependent variables were analysed using non-parametric tests. The median age was 40 years; 53.6% were female. Median HbA1c improved from 62 mmol/mol [7.8%] pre-HCL to 54 mmol/mol [7.1%] post-HCL (P < .001, r = 0.6). No significant HbA1c differences were observed by pump type, gender, or prior pump use. Among those with baseline HbA1c 55–64 mmol/mol (n = 91), 49.5% reached ≤53 mmol/mol, and 20.9% saw a ≥20% reduction. Of those with HbA1c ≥65 mmol/mol (n = 135), 27.4% reached ≤53 mmol/mol, with 55.6% achieving ≥20% reduction. TIR increased from 57% to 67% (P < .001, r = 0.45), and there was a 62% reduction in patients spending ≥4% time in hypoglycaemia. Weight increased from 79.4 kg to 80.8 kg (P < .001, r = 0.3), with 30% experiencing a ≥5% gain and 12.7% a ≥5% loss. HCL pumps significantly improved glycaemic control across all subgroups. Nearly half of those with a HbA1c of 55–64 mmol/mol met target levels. Weight gain was observed in some but with unclear clinical relevance.