d-Nav system helps people with type 2 diabetes optimize insulin doses
medwireNews: The d-Nav system, which calculates insulin dose adjustments according to glucose levels, can help people with type 2 diabetes achieve larger reductions in glycated hemoglobin (HbA1c) levels than with healthcare professional (HCP) support alone, shows a randomized trial in The Lancet.
The authors of a linked commentary, Mark Evans and Rajna Golubic (both from the University of Cambridge, UK) say that “[a]t face value, the approach looks appealing,” although they highlight some unanswered questions and potential drawbacks.
The results of the study, which recruited 181 participants with insulin-dependent type 2 diabetes, build on the findings of the smaller trial the team reported at last year's ADA Scientific Sessions.
During 6 months of follow-up, the average HbA1c of the 93 patients randomly assigned to use the system fell by 1.0% (11 mmol/mol), from a baseline of 8.7% (72 mmol/mol), whereas that of the 88 who received HCP support alone declined by only 0.3% (3.3 mmol/mol) from a baseline of 8.5% (69 mmol/mol).
This gave an effect size of 0.7% (7.7 mmol/mol), say Richard Bergenstal (International Diabetes Center, Minneapolis, Minnesota, USA) and co-researchers.
The proportion of study participants with HbA1c below 8.0% increased from 23% to 62% in the intervention group versus from 32% to 33% in the control group, while 15% versus 43% had a deterioration in HbA1c levels.
Both groups had the same amount of HCP contact, comprising three in-person visits and four phone calls across 6 months.
In their commentary, Evans and Golubic caution that “[i]n the real world, if such frequency of contact was an essential requirement for success of the system, it would be challenging for many services.”
On the other hand, they note that the d-Nav system adjusted users’ insulin doses an average of 1.1 times per week, which they say “would be pragmatically unachievable in routine practice.”
The system is able to recommend dose reductions as well as increases; one in every 6.5 adjustments was a dose reduction. The reduced HbA1c level in the d-Nav group did not come at the expense of more hypoglycemia, with three patients in the intervention group and two in the control group experiencing a severe event (requiring the assistance of another person).
However, the commentators note that “an important question for more widespread future use would be whether automated insulin dose titration would result in increased hypoglycaemia in those at high risk at baseline.”
The average insulin dose used rose from 0.77 to 1.24 units/kg per day in the intervention group versus 0.71 to 0.76 units/kg per day in the control group. Weight also rose more in the intervention group, but only by 2.3% versus 0.7%.
“The world of type 1 diabetes, with greater complexity of insulin dosing than for type 2 diabetes, is already moving rapidly towards automated closed-loop insulin delivery,” conclude Evans and Golubic. “Faced with increasing pressures and demands on primary care, a substantial niche seems likely for technology to help in type 2 diabetes.”
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