Sustained Impact of Real-Time Continuous Glucose Monitoring in Adults With Type 1 Diabetes on Insulin Pump Therapy

OBJECTIVE: In recent years, a growing number of people with type 1 diabetes have gained access to real-time continuous glucose monitoring (rtCGM). Long-term benefits of rtCGM are unclear because of a lack of large studies of long duration. We evaluated whether real-world rtCGM use up to 24 months offered benefits, particularly in those living with impaired awareness of hypoglycemia (IAH).

RESEARCH DESIGN AND METHODS: This 24-month, prospective, observational, cohort study followed 441 adults with insulin pumps receiving full reimbursement for rtCGM. Forty-two percent had IAH. The primary end point was evolution of HbA1c, with secondary end points change in acute hypoglycemia complications, diabetes-related work absenteeism, and quality of life scores. Additionally, we evaluated whether people could achieve glycemic consensus targets during follow-up.

RESULTS: After 24 months, HbA1c remained significantly lower compared with baseline (7.64% [60 mmol/mol] vs. 7.37% [57 mmol/mol], P < 0.0001). Sustained benefits were also observed for the score on the hypoglycemia fear survey and hypoglycemia-related acute complications irrespective of hypoglycemia awareness level. People with IAH had the strongest improvement, especially for severe hypoglycemia (862 events in the year before vs. 119 events per 100 patient-years in the 2nd year, P < 0.0001). Over 24 months, more people were able to meet hypoglycemia consensus targets at the expense of slightly fewer people achieving hyperglycemia consensus targets. Furthermore, the number of people with HbA1c <7% (<53 mmol/mol) without severe hypoglycemia events more than doubled (11.0% vs. 25.4%, P < 0.0001).

CONCLUSIONS: Use of rtCGM led to sustained improvements in hypoglycemia-related glucose control over 24 months. Lower fear of hypoglycemia, less acute hypoglycemia-related events, and diabetes-related days off from work were observed, particularly in those with IAH.