Low glucose at 3-hour 100 gram oral glucose tolerance test: implications for glucose control

Abstract

Objective

To assess the clinical significance of a low 180-minute glucose value in a 100 g oral glucose tolerance test (OGTT) and a single high abnormal value.

Methods

A retrospective cohort study. The study group included women with 180-minute plasma glucose levels of ≤60 mg/dL and one abnormal value in the OGTT. The control group was comprised of women with one abnormal value in the OGTT and normal 180-minute glucose value. The primary outcome was glycemic control, defined as fasting blood glucose measurements > 90 mg/dL or post-prandial glucose values >140 mg/dL or 120 mg/dL (one-hour and two-hour post-prandial, respectively) in >30% of the measurements. Secondary outcomes were the rate of insulin treatment and the perinatal outcome consisting of birthweight, large-for-gestational-age, and polyhydramnios.

Results

Three hundred and one women were included, 143 in the study group and 158 in the control group. Pre-pregnancy BMI, first trimester fasting glucose levels, previous GDM, and familial diabetes were similar for both groups. Suboptimal glycemic control was more prevalent among the women in the study group (14% vs. 5.1%, respectively, p= .01). The need for insulin treatment was similar in both groups.

Conclusions

Women with one abnormal value and a 180-minute hypoglycemia in the OGTT are at increased risk for suboptimal glycemic control.

KEYWORD:

• Gestational diabetes
• pregnancy
• oral glucose tolerance test
• glycemic control
• insulin

Acknowledgements

Details of ethics approval: IRB TLV 0273-19 Jan 2019.

Paper presentation information: Presented as a poster at the SMFM's 40th Annual Pregnancy Meeting, Grapevine, Texas, February 3–8, 2020.

Authors contributions

Lee Reicher, Anat Lavie, and Larissa Feinmesser – manuscript writing/editing. Sharon Maslovitz, Yariv Yogev, and Lee Reicher – protocol/project development. Emmanuel Attali and Isca Landesberg – data collection and management.

Disclosure statement

The authors report no conflict of interest.