CGM best at assessing Night time hyperglycemia in Gestational Diabetes: Study

The study included ninety women of mean gestational age weeks 27. A 7-day masked-CGM was performed within 2 weeks of GDM diagnosis, immediately post-GDM education, but before insulin commencement as determined by SMBG. CGM data regarding hyperglycemia, time with health care professionals, treatment, and pregnancy outcome were collected. Comparisons were performed between subjects subsequently commenced on insulin versus those continued with diet and lifestyle measures alone.

The following results were observed-

a. Those prescribed insulin (n = 34) compared with those managed with diet and lifestyle alone (n = 56) had a greater time in hyperglycemia.

b. Of those not prescribed insulin, 61% breached Gestational diabetes mellitus cutoffs between 00:00 and 06:00 h; 20% breached 6.00–00.00 h CGM cutoffs for >10% of the time; and 47% with optimal CGM glucose levels during the daytime spent >10% time in hyperglycemia between 00.00 and 06:00 h.

c. In contrast, SMBG measurements exceeded the clinical targets of <120 mg/dL post dinner in 5.4% and <100 mg/dL fasting in 0% of the subjects.

Hence, the authors concluded that "although CGM provides a more comprehensive assessment of nocturnal hyperglycemia than SMBG and could improve targeting of interventions in GDM, larger studies are needed to define CGM targets better, which once established will inform studies aimed at targeting nocturnal glucose levels."

For further reference:

https://doi.org/10.1089/dia.2020.0073