MUNICH -- Continuous glucose monitoring (CGM) kept levels in range for more of the day and cut down on severe hypoglycemia in type 1 diabetes patients with impaired awareness of these events, the randomized IN CONTROL trial showed.
Real-time monitoring with the device raised the proportion of time spent in normoglycemia (4 to 10 mmol/L, or 72 to 180 mg/dL) to 65.0% compared with 55.4% on standard self-monitoring of blood glucose (P<0.0001), Cornelis van Beers, MD, of VU University Medical Center in Amsterdam, and colleagues found.
Time hypoglycemic (≤3.9 mmol/L, or 70 mg/dL) dropped to 6.8% compared with 11.4% (P<0.0001), while time in hyperglycemia dropped significantly as well, the researchers reported here at the European Association for the Study of Diabetes meeting and simultaneously online in .
The number of severe hypoglycemic events requiring third-party assistance was lower with CGM as well, at 14 events versus 34 events during self-monitoring (P=0.033).
"In earlier trials, CGM did not live up to the expectations of the diabetes community regarding its ability to reduce severe hypoglycemia," the researchers noted. "However, our findings here support the benefit of CGM, both with and without combining it with continuous subcutaneous insulin infusion, for improving glycemic control and diminishing severe hypoglycemia in adult patients with type 1 diabetes and impaired awareness of hypoglycemia, who are at highest risk of severe hypoglycemia."
IN CONTROL furthers the evidence for CGM for the estimated 20% of adults with type 1 diabetes who have hypoglycemia unawareness, , of the Oregon Health and Science University in Portland, agreed in an accompanying editorial.
"Until these data became available, whether appropriate CGM use (with either continuous subcutaneous insulin infusion or multiple daily insulin injections) truly affects hypoglycemia was unclear," he wrote. "Although perhaps not providing a final verdict, van Beers and colleagues' findings strengthen the evidence in favor of obtaining approval from regulatory agencies for CGM use in this setting, certainly in patients who have clearly defined impaired awareness of hypoglycemia."
While the study "suggests that CGM does help patients get their blood glucose into the target range for more of the day and prevent hypoglycemic events," it leaves room for improvement, , of the University of North Carolina at Chapel Hill, commented to Ƶ.
"The only disappointment is that it did not do even better, particularly with the most severe events of hypoglycemia with coma or seizure or requiring third-party assistance," he added. "Better devices, better training, or longer-term use in future studies or clinical care will hopefully resolve the remaining deficiencies."
The trial included 52 patients at two medical centers in the Netherlands who had type 1 diabetes and hypoglycemia awareness of Gold score 4 or worse on continuous subcutaneous insulin infusion or multiple daily insulin injections and doing at least three self-checks of glucose per day at baseline.
They were randomized to real-time CGM system with a Paradigm Veo system, a MiniLink transmitter, and an Enlite glucose sensor or to self-monitoring of blood glucose for 16 weeks in an open-label, crossover design with 12 week washout before switching to the other method. Both groups got re-education on diabetes management after enrollment.
El Youssef highlighted the 89.4% median sensor use, which was greater than the about 57% use in the prior , one portion of which compared CGM against conventional glucose self-monitoring.
But IN CONTROL didn't show any improvement in hypoglycemia awareness, whereas HypoCOMPaSS had.
"As suggested by van Beers and colleagues, the HypoCOMPaSS study probably showed improvements in hypoglycemia awareness mostly because of extensive intervention and education, an interpretation supported by results from a meta-analysis from Yeoh and colleagues in which structured education to reduced hypoglycemia over longer durations resulted in significant improvement in hypoglycemia awareness," he wrote.
"Yet, the reason for the absence of improvement in hypoglycemia awareness over the 16-week period in van Beers and colleagues' study is unclear. A more significant reduction of time spent in hypoglycemia might have been needed, or a longer study period for assessing return of symptoms, but perhaps sensor accuracy during hypoglycemia was problematic as well."
"Additionally, although time in severe hypoglycemia was reduced with CGM in the IN CONTROL trial, it was not completely eliminated, and even a small amount of time spent at very low glucose ranges could limit improvement in hypoglycemia unawareness," he added.
Disclosures
The study was funded by Eli Lilly and Sanofi. Medtronic provided continuous glucose monitoring devices.
Van Beers disclosed no relevant relationships with industry, but his institution has received research grants from AstraZeneca, Boehringer Ingelheim, Novo Nordisk, and Sanofi through some of his co-authors.
El Youssef disclosed no relevant relationships with industry.
Primary Source
Lancet Diabetes and Endocrinology
Van Beers CAJ, et al "Continuous glucose monitoring for patients with type 1 diabetes and impaired awareness of hypoglycaemia (IN CONTROL): A randomised, open-label, crossover trial" Lancet Diabetes Endocrinol 2016; DOI: 10.1016/ S2213-8587(16)30193-0.
Secondary Source
Lancet Diabetes and Endocrinology
El Youssef J "IN CONTROL of type 1 diabetes, despite hypoglycaemia unawareness" Lancet Diabetes Endocrinol 2016; DOI: 10.1016/ S2213-8587(16)30261-3.