The continuous glucose monitoring system is useful for detecting unrecognized hypoglycemias in patients with type 1 and type 2 diabetes but is not better than frequent capillary glucose measurements for improving metabolic control.
OBJECTIVE
To evaluate whether the continuous glucose monitoring system (CGMS; MiniMed, Sylmar, CA) is useful for investigating the incidence of unrecognized hypoglycemias in type 1 and type 2 diabetic patients and for improving metabolic control in type 1 diabetic patients.


METHODS
A total of 70 diabetic subjects (40 type 1 and 30 type 2 subjects) were monitored using the CGMS. The number of unrecognized hypoglycemias was registered. Furthermore, the 40 type 1 diabetic patients whose treatment was modified in accordance with the information obtained from the CGMS were compared with a control group of 35 different type 1 diabetic patients using intensive capillary glucose measurements. HbA(1c) levels were measured before the monitoring period and 3 months later.


RESULTS
The CGMS detected unrecognized hypoglycemias in 62.5% of the type 1 diabetic patients and in 46.6% of the type 2 diabetic patients. We found that 73.7% of all events occurred at night. HbA(1c) concentrations decreased significantly in both the group of type 1 diabetic subjects monitored with the CGMS (from 8.3 +/- 1.6 to 7.5 +/- 1.2%, P < 0.01) and the control group (from 8.0 +/- 1.4 to 7.5 +/- 0.8%, P < 0.01). The greatest reduction was observed in the subgroup of patients who started continuous subcutaneous insulin infusion therapy, both in the CGMS-monitored and control groups (from 9.4 +/- 2 to 7.2 +/- 1.4% and from 8.1 +/- 1.8 to 7.1 +/- 0.6%, respectively).


CONCLUSIONS
The CGMS is useful for detecting unrecognized hypoglycemias in type 1 and type 2 diabetic subjects; however, it is not better than standard capillary glucose measurements for improving metabolic control of type 1 diabetic subjects, regardless of the therapeutic regimen.
Chico
Ana
A
Institute of Diabetology, Fundació Sardà Farriol, Barcelona, Spain. 28299acb@comb.es
Vidal-Ríos
Pablo
P
Subirà
Montserrat
M
Novials
Anna
A
D000328:Adult; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism*; D002196:Capillaries; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods*; D008991:Monitoring, Physiologic / Q000379:methods
D001786:Blood Glucose; D006442:Glycated Hemoglobin