Closed-loop system improves glycemic control in people with type 2 diabetes on dialysis
medwireNews: Findings from an exploratory randomized crossover trial suggest that closed-loop insulin delivery leads to better glycemic control than standard insulin treatment in people with type 2 diabetes and end-stage renal disease (ESRD) requiring maintenance dialysis in the outpatient setting.
“Management of diabetes in this population is challenging,” say the researchers, noting that “[m]ost oral diabetes medications are contraindicated in people with ESRD,” and therefore insulin is the most frequently used diabetes therapy.
For the open-label trial, 26 participants on subcutaneous insulin therapy at baseline were randomly assigned to receive 20 days of fully closed-loop glucose control with faster-acting insulin aspart followed by 20 days of standard treatment with multiple daily injections of insulin, or vice versa, with an average washout period of 17 days. Closed-loop delivery was carried out using the CamDiab system, comprising the Dexcom G6 sensor, the Cambridge adaptive model predictive control algorithm on an unlocked Android smartphone, and the Dana Diabecare RS insulin pump.
Charlotte Boughton (Addenbrooke’s Hospital, Cambridge, UK) and team report in Nature Medicine that participants spent a significantly higher proportion of time in the target glucose range of 5.6–10.0 mmol/L (101.0–180.2 mg/dL) during the closed-loop than the control period, at an average of 52.8% versus 37.7%.
Mean glucose levels were also significantly lower with closed-loop versus standard insulin delivery, at 10.1 and 11.6 mmol/L (182.0 and 209.0 mg/dL), respectively, as was the median proportion of time spent in hypoglycemia, at 0.12% versus 0.17%.
Boughton and colleagues report that efficacy of the closed-loop system “improved considerably over the study period with algorithm adaptation,” with the average time in range improving from 36% on day 1 to more than 60% at the end of the 20 days.
“This finding highlights the importance of an adaptive algorithm that can adjust in response to individuals’ changing insulin requirements over time, independent of its initialization,” they write.
Seven serious adverse events were reported over the course of the study, including one episode of severe hypoglycemia in the closed-loop period, but the team says that closed-loop delivery “had not been in operation at the time of the event or for 24 [hours] previously,” and “[n]one of the serious adverse events were deemed related to study devices or study procedures.”
The researchers also found that usage of the glucose sensor and closed-loop system was “high” in the study, at 93–95%, and all 24 participants who responded to a questionnaire about their experience said they were happy to use the closed-loop system and would recommend it to others.
Boughton and co-authors conclude that “larger studies are now required to confirm these findings and to determine if the glycemic improvements observed with closed-loop are associated with a reduction in complications and improved quality of life, as well as whether closed-loop should be targeted towards specific subpopulations.”
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