Objective: To evaluate the blood glucose concentrations in a group of women with gestational diabetes mellitus (GDM), by the use of a continuous glucose monitoring system (CGMS).
Methods: Seven women with diet-controlled GDM (group G1), 5 with diet- and insulin-controlled GDM (group G2), and 7 healthy, pregnant women (group N) were included in the study. The treatment was adjusted on the basis of self-monitoring of blood glucose (SMBG). The self-monitoring was performed 4 times a day, with the goals of fasting blood glucose values of <90 mg/dL and postprandial (2 hours after each meal) values of <120 mg/dL. Then patients were submitted to a 72-hour period of use of the CGMS.
Results: In the 3 study groups--N, G1, and G2, respectively--no significant differences were noted in individual study parameters, measured with the CGMS in regard to the following: mean 24-hour glycemia (85, 87, and 91 mg/dL), fasting blood glucose (79, 88, and 82 mg/dL), postprandial glucose (96, 97, and 105 mg/dL), mean glucose level during the night (77, 71, and 75 mg/dL), and area under the glycemia curve (281, 315, and 310). Moreover, no significant difference was found in the total duration of glycemia below 60 mg/dL (317, 300, and 370 minutes) or the duration of glycemia of more than 120 mg/dL (259, 225, and 394 minutes) in group N, G1, and G2, respectively. With use of the CGMS, however, in comparison with SMBG, a wider range of glycemic levels was observed in all 3 study groups: for the healthy, pregnant women, 41 to 194 mg/dL versus 61 to 151 mg/dL; for G1, 40 to 244 mg/dL versus 40 to 180 mg/dL; and for G2, 40 to 173 mg/dL versus 50 to 157 mg/dL.
Conclusion: The therapy, based on SMBG levels, when applied to the group of women with GDM, brought the glucose levels under effective control, with mean outcome values similar to those observed in the group of normal pregnant women. Nevertheless, using the CGMS, we detected long, asymptomatic periods of high and low blood glucose levels, both in the patients with GDM and in the unaffected pregnant women. The use of the CGMS for monitoring blood glucose profiles might be beneficial in this group of pregnant women.