Long-term outcome of insulin pump therapy: reduction of hypoglycaemia and impact on glycaemic control.

AIMS: To determine the long-term outcome of continuous subcutaneous insulin infusion (CSII) in Type 1 diabetes according to Catalan National Health Service indications. METHODS: Retrospective observational study including 178 patients with Type 1 diabetes who started CSII treatment in our centre (2003-2008). All patients were followed in our CSII programme for outpatients for at least 5 years. Data on annual HbA1c levels were collected, and the main indication for starting CSII was analysed. RESULTS: Twenty-seven of 178 patients were excluded because of loss to follow-up or withdrawal from CSII, thus 151 patients (aged 37.4 ± 10.5 years, 64% women) were analysed. The main indications for starting CSII were suboptimal metabolic control (60.9%), severe hypoglycaemia/hypoglycaemia unawareness (25.5%) and others (13.6%). HbA1c was 64 ± 13 mmol/mol (8.0 ± 1.2%) at the start of CSII and 62 ± 13 mmol/mol (7.8 ± 1.2%) after 5 years in the total cohort (P = 0.1). The severe hypoglycaemia rates were 0.66 ± 1.61 and 0.17 ± 0.42 episodes/patient/year (P < 0.001). In patients with suboptimal metabolic control, HbA1c decreased from 68 ± 12 mmol/mol (8.4 ± 1.1%) to 64 ± 14 mmol/mol (8.0 ± 1.3%) (P = 0.016), with 37.4% of those in this group having an HbA1c ≤ 58 mmol/mol (7.5%) after 5 years. In patients starting CSII due to severe hypoglycaemia the problem was considered resolved in 93%, and in 64% of those starting CSII because of suboptimal glycaemic control, HbA1c improved significantly. CONCLUSIONS: CSII therapy achieves and maintains its efficacy mainly in terms of reducing severe hypoglycaemia. In the whole group of patients, the reduction in HbA1c is transient and disappears after 5 years.