Metabolic control after years of completing a clinical trial on sensor-augmented pump therapy

Sensor-augmented pump (SAP) therapy has been shown to be effective and safe for improving metabolic control in patients with type 1 diabetes mellitus (T1DM) in a number of trials. Our objective was to assess glycemic control in a group of T1DM patients on insulin pump or SAP therapy after years of participating in the SWITCH (Sensing With Insulin pump Therapy To Control HbA1c) trial and their return to routine medical monitoring.

A retrospective, observational study of 20 patients who participated in the SWITCH trial at our hospital from 2008 to 2010. HbA1c values were compared at the start, during (at the end of the periods with/without SAP use - Sensor On/Sensor Off period respectively - of the cross-over design), and 3 years after study completion. HbA1c values of patients who continued SAP therapy (n=6) or only used insulin pump (n=14) were also compared.

Twenty patients with T1DM (44.4±9.3 years, 60% women, baseline HbA1c level 8.43±0.55%) were enrolled into the SWITCH study). Three years after study completion, HbA1c level was 7.79±0.77 in patients on pump alone, with no significant change from the value at the end of the Off period of the study (7.85±0.57%; p=0.961). As compared to the end of the On period, HbA1c worsened less in patients who remained on SAP than in those on pump alone (0.18±0.42 vs. 0.55±0.71%; p=0.171), despite the fact that levels were similar at study start (8.41±0.60 vs. 8.47±0.45; p=0.831) and at the end of the On period (7.24±0.48 vs. 7.38±0.61; p=0.566). Frequency of CGM use in patients who continued SAP therapy was high (61.2% of the time in the last 3 months).

Our study suggests that the additional benefit of SAP therapy achieved in a clinical trial may persist in the long term in routine clinical care of patients with T1DM.