Continuous glucose monitoring in patients with impaired awareness of hypoglycemia

The authors aimed to determine whether continuous glucose monitoring improved glycemia (glucose present in the blood) and prevented severe hypoglycemia events (dangerously low blood sugar levels) compared to self-monitoring of blood sugar levels in patients with impaired awareness of hypoglycemia.

The authors concluded that continuous glucose monitoring increased the time spent in normoglycemia (maintained a normal blood sugar level) and reduced severe events in patients with type 1 diabetes compared to self-monitoring. 

Glucose levels must be closely monitored to insure severe hypoglycemic or hyperglycemic (dangerously high blood sugar levels) events do not occur. Some people can suffer from impaired awareness of hypoglycemia. This in an acquired complication of insulin treatment where patients are unable to recognize when they have low blood sugar.

Continuous glucose monitoring (CGM) can be used to manage blood sugar levels. CGM involves wearing a small device that monitors glucose intake throughout the day and night, and will notify the wearer when levels are high or low to prevent any events from occurring. Self-monitoring of blood sugar levels, such as through finger prick testing, can also be utilized to prevent glycemic events from occurring. 

The aim of this study was to determine whether CGM improved blood glucose levels and prevented severe hypoglycemic events compared to self-monitoring in type 1 diabetes. 

52 patients were used in this study. Patients were randomly assigned in to two groups. 26 patients were assigned to the CGM followed by self-monitoring of blood glucose (SMBG) group 1. 26 patients were assigned to the SMBG followed by CGM group 2. Each patient used each method for 16 weeks.

The percentage of time patients spent in normoglycemia was higher in patients on CGM (65%) than in patients on SMBG (55.4%). The number of hours a day that patients spent in a normal blood sugar range was higher in CGM patients that in SMBG patients. Fewer hypoglycemic events occurred in CGM patients than in SMBG patients. 19% of CGM patients experienced one or more severe hypoglycemic events compared to 35% in SMBG patients.

The authors concluded that continuous glucose monitoring increased the time spent in normoglycemia (maintained a normal blood sugar level) and reduced severe events in patients with type 1 diabetes compared to self-monitoring. 

Funding and devices were provided by Eli Lilly, Sanofi, and Medtronic.