Effects of intermittently scanned continuous glucose monitoring on blood glucose control and the production of urinary ketone bodies in pregestational diabetes mellitus

OBJECTIVE: To investigate the effects of intermittently scanned continuous glucose monitoring (isCGM) on blood glucose control, clinical value of blood glucose monitoring and production of urinary ketone bodies in pregestational diabetes mellitus. METHOD: A total of 124 patients with pregestational diabetes mellitus at 12–14 weeks of gestation admitted to the gestational diabetes clinic of our hospital from December 2016 to December 2018 were selected and randomly divided into two groups. Sixty patients adopted self-monitoring of blood glucose (SMBG) were taken as the control group, and the other 64 patients adopted isCGM system by wearing the device for 14 days. Blood sugar control, glycosylated albumin level, ketone production in urine, the maximum and minimum of blood sugar value measured by different monitoring methods and their occurrence time were observed in the two groups. RESULT: (1) No statistically significant differences were found between the groups in terms of maternal age, gestational age at first visit, family history, duration of diabetes, education level, total insulin dose, chronic hypertension, abortion history, nulliparity, assisted reproductive technology, history of macrosomia childbirth, pre-pregnancy BMI, and overweight (%) at the first visit and hypoglycemia, (2) the value of Glycated Albumin was lower in the CGM group compared to the control group at 2ed weeks (14.6 ± 2.2 vs. 16.8 ± 2.7, p < 0.001). The women in the CGM group spent increased time in the recommended glucose control target range of 3.5–7.8 mmol/L (69 ± 10% vs. 62 ± 11%, p < 0.001) and reduced time above target compared with those in the control group at 2 weeks (25 ± 7% vs. 31 ± 8%, p < 0.001). In the second week of the study, the positive rate of urinary ketone body in isCGM group was lower than that in the control group (42 ± 5 vs. 54 ± 5, p < 0.001), and (3) the minimum blood glucose of 31.2% (20/64) cases in isCGM group appeared during 0:00–2:59 at night, and 26.6% (17/64) cases appeared during 3:00–5:59 at night. The minimum values of 40.0% (24/60) cases in the control group appeared within the 30 min before lunch, 23.3% (14/60) within the 30 min before breakfast, and 11.7% (7/60) within the 30 min before dinner. The cases of minimum of blood sugar before meals accounted for 75% of all the minimum values, and the cases of minimum at night only accounted for 8.3%. CONCLUSION: Intermittently scanned continuous glucose monitoring can reduce hyperglycemia exposure and ketone body formation in pregestational diabetes mellitus. In addition, isCGM is better than SMBG in detecting nocturnal hypoglycemia.