Improved Glycemic Control in Poorly Controlled Patients with Type 1 Diabetes Using Real-Time Continuous Glucose Monitoring

Abstract

Intensive self-management with frequent self-monitoring of blood glucose (SMBG) is important in type 1 diabetes to achieve good metabolic control (1–3). Nevertheless, many patients still experience episodes of unrecognized hypo- and hyperglycemia (4). Novel technologies for continuous glucose monitoring (CGM) that provide information about glucose excursions are now available. Previous studies reported the benefits of retrospective evaluation of CGM data (5–11), but few assessed effects on glycemic control (5,12–14), and only one showed improvements compared with SMBG (14). We evaluated the effect of a new real-time glucose monitor on glycemic control in patients with poorly controlled type 1 diabetes. The device, Guardian RT (Medtronic MiniMed, Northridge, CA), allows users to see glucose readings and set hypo- and hyperglycemic alarms and provides trend information on changing glucose values. The study included 81 children (median age 14.4 years [range 8.0–18.9]) and 81 adults (age 39.1 years [19.0–59.5]) with stable type 1 diabetes. All had adhered to intensified insulin treatment (continuous subcutaneous insulin infusion, n = 78; multiple daily injection, n = 84) but had HbA1c (A1C) levels ≥8.1%. Informed consent was obtained from patients regularly attending the eight participating centers. Subjects were randomly assigned 1:1:1 for 3 months to Guardian RT continuously (arm 1) or biweekly for 3-day periods every 2 weeks (arm 2) or to continue conventional SMBG (control). Treatment adjustments made by physicians and patients were based on SMBG profiles in control subjects and on real-time glucose profiles in arms 1 and 2. Patients were instructed to perform confirmatory SMBG measurements before therapeutical interventions or corrective action if hypo- or hyperglycemic alarms or symptoms occurred. …