Short-term CGM uncovers type 1 diabetes management issues
medwireNews: Just 1 week of continuous glucose monitoring (CGM) can uncover hidden problems and lead to treatment changes and improved glucose control in patients with type 1 diabetes, say the DIACCOR study investigators.
The most common issue found in the 408 patients who had interpretable data after their initial 7-day period of CGM was postprandial hyperglycemia, identified in 64.4% of patients. CGM also showed that 44.1% of patients were using an inadequate prandial insulin bolus, 39.9% had nocturnal hyperglycemia, 35.6% had asymptomatic nocturnal hypoglycemia, 34.2% had elevated average 24-hour glucose levels, and the same proportion had successions of hypoglycemia and hyperglycemic episodes.
In addition, 23.5% had the “dawn phenomenon” (an abnormal early-morning rise in blood glucose). Other issues included too short a duration of insulin action, incorrect dosing for exercise, and missed injections.
The patients were aged between 13 and 84 years and had been offered diagnostic CGM because of persistently high glycated hemoglobin (HbA1c) levels (>7.5%, >58.5 mmol/mol), a history of severe hypoglycemia, or documented hypoglycemia occurring more than four times per week.
“[A] 1-week sensor wear helped patients and physicians to identify issues beyond HbA1c results,” write Bruno Guerci (University of Lorraine, Nancy, France) and co-researchers in Diabetes Technology & Therapeutics.
The period of CGM led to diabetes management changes, with doctors proposing changes in insulin dosing or regimen for 80.7% of patients, which included a switch to continuous subcutaneous insulin infusion (CSII) for 16.3%, additional insulin injections, and initiation or reinforcement of carbohydrate counting.
Reinforcement of diabetes management education without changes in insulin regimen was proposed for 19.3% of patients. And despite the lack of regimen change, these patients had a 0.5% reduction in HbA1c by the time of follow-up, 4 months after the CGM phase.
This “suggests that for most of the patients, an issue, such as abnormal eating behavior and/or overcorrection of hypoglycemia and/or inappropriate bolus timing, was identified with a short-term CGM sequence and fixed with educational reinforcement,” say the researchers.
Patients who received treatment intensification had a 0.32% fall in HbA1c and those who switched to CSII had a 0.69% reduction. In the group overall there was a “dramatic drop” in incidences of severe hypoglycemia (7.9 vs 17.0 %) and frequent mild hypoglycemia (10.8 vs 24.2%) relative to at baseline, as well as smaller decreases in inadequate prandial boluses and asymptomatic nocturnal hypoglycemia.
Guerci and team stress that a brief period of CGM “does not provide the same benefits as continuous CGM,” but suggest it as an intervention for patients unwilling to wear a sensor on a long-term basis.
Also, they speculate that some patients in their study, such as those with a history of severe hypoglycemia, had previously refused insulin pump therapy.
“Wearing a pump as a monitor for a few days probably favored CSII acceptation for some patients,” they suggest.
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