Intensive glycemic control in gestational diabetes mellitus: a randomized controlled clinical feasibility trial

Abstract

Background: Overweight and obese women with gestational diabetes mellitus are at increased risk for adverse perinatal outcomes, and they are also more likely to have suboptimal glycemic control. However, there is a paucity of data evaluating whether lower glycemic targets could improve outcomes.

Objective: To evaluate the feasibility of intensive glycemic control in overweight and obese women with gestational diabetes mellitus.

Materials and methods: We randomized 60 overweight or obese women with gestational diabetes mellitus, diagnosed between 12 and 32 weeks' gestation to either intensive (fasting <90 mg/dL, 1 hour postprandial <120 mg/dL) or standard (fasting <95 mg/dL, 1 ho postprandial <140 mg/dL) glycemic targets. Maternal glucose was assessed in 2 ways: blinded continuous glucose monitors, worn for 5 days at 2 time points (at 12-32 weeks and again at 32-36 weeks), and self-monitored glucose measurement 4 times per day. All women underwent standardized dietary counseling, and medical therapy was prescribed as needed to achieve glycemic control.

Results: Between December 2015 and December 2017, we randomized 60 women to either intensive (n = 30) or standard (n = 30) glycemic control. Baseline characteristics including maternal age, body mass index, and gestational age at diagnosis were similar between the intensive and standard groups. Medical therapy was more common in women in the intensive group than those in the standard group (83 vs 57%, P = .02). Women in the intensive glycemic control group had lower glucose values as assessed by continuous glucose monitors at including 24-hour mean (-8.1; 95% confidence interval, -12.0 to -4.3 mg/dL; P < .0001) and 1-h postprandial (-11.8; 95% confidence interval, -19.7 to -3.9 mg/dL, P = .004) values. Hypoglycemia <60 mg/dL was uncommon and did not differ between groups.

Conclusion: Intensive glycemic targets can be used in overweight and obese women with minimal hypoglycemia, and this approach results in improved glycemic control when compared to standard glycemic targets. Further studies are needed to determine whether intensive glycemic targets can improve maternal and neonatal outcomes in high-risk women with gestational diabetes mellitus.

Clinical trial identifier: NCT02530866; clinicaltrials.gov.

Keywords: continuous glucose monitoring; gestational diabetes mellitus; glycemic control; hypoglycemia; obesity; overweight; pregnancy.