Constant glucose monitoring helps control diabetes

"Real-time" continuous monitoring of blood sugar (glucose) may help improve glycemic control in patients with poorly controlled type 1 diabetes, according to findings published in the current issue of Diabetes Care.

"Intensive self-management with frequent self-monitoring of blood glucose is important in type 1 diabetes to achieve good metabolic control," Dr. Jan Bolinder, of Karolinska University Hospital Huddinge, Stockholm, and colleagues write. Nevertheless, many patients still have undetected episodes of blood glucose levels that are too low (hypoglycemia) or too high (hyperglycemia.)

The researchers therefore examined the effect of a new real-time glucose monitor (Guardian RT) on glycemic control in poorly controlled type 1 diabetes. The device, in which a monitor is implanted beneath the skin, allows users to be able to see their glucose reading at any time and to set an alarm to go off if the reading becomes too low or too high. In addition, the monitor provides a record of changing glucose values over time.

The study included 81 children and 81 adults, who had adhered to intensified insulin treatment, but still had high glucose levels (HbA1c of 8.1 percent or greater).

For a 3-month period, the patients were randomly assigned to use the Guardian RT continuously or for 3 days every 2 weeks, or to continue with conventional self-monitoring.

If hypo- or hyperglycemic alarms or symptoms occurred, the subjects were asked to confirm their glucose levels and then take corrective actions. Overall, 156 patients completed the study.

An association was seen after 1 month between reductions in glucose and the continuous use of the Guardian RT. However, there were no significant differences seen in the patients assigned to use the Guardian RT for 3 days every 2 weeks or those in the conventional self-monitoring group.

By the end of the study, 50 percent of the patients in the continuous use group had glucose reductions of at least 1 percent, compared with 37 percent in the 3-day group and 15 percent in the conventional monitoring group.

A 2 percent or greater glucose reduction was seen in 26 percent of the continuous use group, compared with 9 percent in the 3-day group and 4 percent in the conventional group, Bolinder and colleagues report.

The team concludes that this is "the first randomized...trial to demonstrate a clinically meaningful reduction in A1c using real-time continuous glucose monitoring in type 1 diabetic patients."

SOURCE: Diabetes Care, December 2006.