Use of continuous glucose monitoring system in the management of severe hypoglycemia

Severe hypoglycemia can have a dramatic impact on daily life for people with diabetes. Hypoglycemia is quantifiable by the HYPO-Score derived from the frequency of severe hypoglycemia over a year and a component based on 4 weeks of glucose records. The latter gives a modified HYPO-Score as a short-term measure of hypoglycemia. We used a continuous glucose monitoring system (CGMS) in patients with severe hypoglycemia to assess if we could decrease hypoglycemia as measured by the modified HYPO-Score.

Sixteen type 1 diabetes subjects, 52.0 +/- 2.3 years old with a diabetes duration of 29.4 +/- 2.8 years having problematic hypoglycemia were enrolled. All used multiple daily insulin injections, and the glycosylated hemoglobin level was 8.4 +/- 0.3%. After a month of gathering hypoglycemia information for baseline modified HYPO-Score, subjects wore the CGMS for 2 months, and a modified HYPO-Score was repeated. To assess long-term benefit, CGMS was then discontinued for 3 months, and a final modified HYPO-Score was determined.

The modified HYPO-Score decreased from 857 +/- 184 to 444 +/- 92 (P = 0.055) (intention-to-treat basis). Further analysis of the modified HYPO-Score when the CGMS was actually functioning showed it decreased from 857 +/- 184 to 366 +/- 86 (P = 0.023). Severe hypoglycemia episodes dropped from 16 at baseline to three when wearing the CGMS. The number of hypoglycemia episodes <3.0 mmol/L dropped from 8.6 +/- 1.5 to 4.7 +/- 0.9 (P = 0.01). Subjects expressed less fear of hypoglycemia with CGMS. In 11 who completed modified Final Month HYPO-Scores, the number of severe hypoglycemic events rose to six. At study end, 13 of 16 subjects elected to continue using the CGMS.

When the CGMS was worn and functioning there was a significant decrease in the modified HYPO-Score and number of hypoglycemic values <3.0 mmol/L.