Glycaemic impact of patient-led use of sensor-guided pump therapy in type 1 diabetes: a randomised controlled trial

Aims/hypothesis  The objective of this study was to assess the impact of patient-led sensor-guided pump management on glycaemic control, and compare the effect with that of standard insulin pump therapy. Methods  An open multicentre parallel randomised controlled trial was conducted at five tertiary diabetes centres. Participants aged 13.0–40.0 years with well-controlled type 1 diabetes were randomised 1:1 to either study group for 3 months. Randomisation was carried out using a central computer-generated schedule. Participants in the intervention group used sensor-guided pump management; no instructive guidelines in interpreting real-time data were provided (‘patient-led’ use). Participants in the control group continued their original insulin pump regimen. Continuous glucose monitoring (CGM) and HbA_1c level were used to assess outcomes. The primary outcome was the difference in the proportion of time in the target glycaemic range during the 3 month study period (derived from CGM, target range 4–10 mmol/l). Secondary outcomes were difference in HbA_1c, time in hypoglycaemic (≤3.9 mmol/l) and hyperglycaemic (≥10.1 mmol/l) ranges and glycaemic variability. Results  Sixty-two participants were recruited and randomised; 5/31 and 2/31 withdrew from intervention and control groups, respectively, leaving 26/31 and 29/31 for the intention-to-treat analyses. When adjusted for baseline values, the mean end-of-study HbA_1c was 0.43% lower in the intervention group compared with the control group (95% CI 0.19 to 0.75%; p = 0.009). No difference was observed in CGM-derived time in target (measured difference 1.72; 95% CI −5.37 to 8.81), hypoglycaemic (0.54; 95% CI −3.48 to 4.55) or hyperglycaemic (−2.18; 95% CI −10.0 to 5.69) range or in glycaemic variability (−0.29; 95% CI −0.34 to 0.28). Within the intervention group, HbA_1c was 0.51% lower in participants with sensor use ≥70% compared with participants with sensor use <70% (95% CI −0.98 to −0.04, p = 0.04). Five episodes of device malfunction occurred. Conclusions/interpretation  Individuals established on insulin pump therapy can employ sensor-guided pump management to improve glycaemic control. An apparent dose-dependent effect of sensor usage was noted; however, frequent use of this technology (≥70%) was not universally acceptable. Trial registration: ACTRN12606000049572 Funding: Funding support and equipment were provided by Medtronic Australasia.