Issue 128 Item 2 Improved Outcomes Using the Continuous Glucose Monitor (CGM) fo

Study shows improved outcomes with the use of the continuous glucose monitoring system (CGMS) designed for home use (MiniMed, Sylmar, California). The CGMS is a Holter-type monitor that makes minute-by-minute recordings of glucose levels. From a group of 44 diabetic children, adolescents and young adults who tried the device, Dr. Silvana Salardi’s team selected 28 subjects whose recordings showed no interruption over 72 hours. The participants were also required to have had an HbA1c level of at least 8% for more than 1 year or a history of frequent hypoglycemia.

Their mean age was 14.8 years (range 5.7 to 24.8). During the 3 days that the patients wore the device, they kept written records of events such as insulin dose and food intake, and they also recorded these events electronically in the monitor.

Using three 24-hour glucose profiles from the CGMS, the researchers calculated the mean amount of glucose each patient produced over the study period. These values were significantly correlated with fructosamine and HbA1c levels, they determined. Furthermore, the correlation was as strong as in a pediatric study where glucose was measured by multiple daily blood tests over 30 days.

The research team noted rapid glycemic excursions in 8 of the 28 patients, asymptomatic nocturnal hypoglycemic episodes in 12, and prolonged hyperglycemic episodes in 23. In the latter group, 15 patients had values of at least 400 mg/dL, including 5 patients who had HbA1c levels under 8%.

At 3 and 6 months after the 3-day study, HbA1c levels were significantly reduced from baseline values. Five patients maintained a reduction of at least 1% for 6 months.

"It is possible to improve metabolic control and decrease Hb1Ac by following the modifications suggested by the CGMS," Dr. Salardi’s group concludes. Even in patients who do not reliably self-monitor blood glucose, the authors add, "it is possible to obtain information useful to modifying the insulin treatment and decreasing HbA1c levels. This occurred in some of our poorly compliant patients."

Postprandial peaks were rare, the researchers note. They suggest that "efforts to improve HbA1c should be directed toward lowering not only postprandial values but, above all, the whole 24-h glycemic profile." Diabetes Care 2002;25:1840-1844.