medwireNews: A closed-loop insulin delivery system may offer significantly better glycemic control than an open-loop system with predictive low glucose suspend (PLGS) in islet transplant candidates with highly unstable type 1 diabetes, research shows.
The Diabeloop for highly unstable diabetes (DBLHU) system was tested in seven patients (100% women, mean age 44 years) whose severe hypoglycemia was poorly controlled by the PLGS system, and who were either contraindicated for or did not accept islet transplantation.
Pierre‐Yves Benhamou (University Grenoble Alpes, France) and colleagues explain in Diabetes, Obesity and Metabolism that the DBLHU system consists of a Dexcom G6 continuous glucose monitor (CGM), a Kaleido insulin pump, and the investigational DBLHU handset software, which was an adaptation of the Diabeloop closed-loop system DBLG1.
DBLHU-W10 study participants were randomly assigned to receive 4 weeks of treatment with either the DBLHU system or the PLGS system (Enlite CGM sensor plus a Medtronic 640G insulin pump through a Smartguard safety system) followed by a switch to the alternative for a further 4 weeks. They then repeated the process either in the same or a different order for a second cycle.
Among the five patients who completed the study, the researchers found that time in glycemic range (TIR; 70–180 mg/dL, 3.9–10.0 mmol/L) was significantly higher with DBLHU than with PLGS, at 73.3% versus 43.5% of daily time or 17 hours 35 minutes versus 10 hours 26 minutes. This resulted in a mean difference of 29.8% of time or 7 hours 9 minutes between the two treatments. Individual mean differences ranged from 11.1% to 50.0%.
Use of the DBLHU system was also associated with spending a significantly lower proportion of daily time in hypoglycemia (<70 mg/dL; 0.9 vs 3.7%) and in hyperglycemia (>180 mg/dL; 25.8 vs 52.8%), as well as significant improvements in sensor glucose values, glucose variability indices, and satisfaction scores on the Diabetes Treatment Satisfaction Questionnaire.
There were no treatment-related adverse events, but Benhamou et al point out that “DBLHU therapy was not effective in fully preventing severe hypoglycaemia in one of the seven included patients.”
They suggest: “This type of resistant patient should be considered for islet transplantation.”
The researchers also note that the DBLHU system recently obtained CE marking approval as a result of the positive DBLHU-W10 study findings.
They say: “Our current results provide a strong argument for its cost being at least equivalent to the one claimed by PLGS systems, which is significantly lower than the cost of each of the two existing treatment options for [unstable diabetes], namely, islet transplantation or intraperitoneal insulin delivery with implantable pumps.”
And the team concludes: “Further studies are required to investigate if the DBLHU system can be a therapeutic alternative to islet transplantation in a step-by-step approach to treating unstable [type 1 diabetes].”
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