The one-hour oral glucose tolerance test to predict glucose intolerance postpartum in women with prior gestational diabetes

Niels Bochanen; Yana Vanlaer; Caro Minschart; Nele Myngheer; Toon Maes; Block Christophe De; Pottelbergh Inge Van; Pascale Abrams; Wouter Vinck; Liesbeth Leuridan; Sabien Driessens; Jaak Billen; Christophe Matthys; Annick Bogaerts; Annouschka Laenen; Chantal Mathieu; Katrien Benhalima

doi:10.1530/endoabs.112.009

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Endocrine Abstracts (2025) 112 009 | DOI: 10.1530/endoabs.112.009

BES2025 BES 2025 CLINICAL STUDIES (21 abstracts)

The one-hour oral glucose tolerance test to predict glucose intolerance postpartum in women with prior gestational diabetes

Niels Bochanen ^1,2 , Yana Vanlaer ¹ , Caro Minschart ¹ , Nele Myngheer ³ , Toon Maes ⁴ , Christophe De Block ² , Inge Van Pottelbergh ⁵ , Pascale Abrams ^6,7 , Wouter Vinck ⁷ , Liesbeth Leuridan ⁸ , Sabien Driessens ⁸ , Jaak Billen ⁹ , Christophe Matthys ¹ , Annick Bogaerts ^10,11 , Annouschka Laenen ¹² , Chantal Mathieu ¹ & Katrien Benhalima ¹

Author affiliations

¹Department of Clinical and Experimental Endocrinology, University Hospitals Leuven, Belgium; ²Department of Endocrinology-Diabetology-Metabolism, Antwerp University Hospital, Belgium; ³Department of Endocrinology, AZ Groeninge, Belgium; ⁴Department of Endocrinology, Imelda Hospital, Belgium; ⁵Department of Endocrinology, AZORG, Belgium; ⁶Department of Endocrinology, ZAS Sint-Vincentius, Belgium; ⁷Department of Endocrinology, ZAS Sint-Augustinus, Belgium; ⁸Department of Endocrinology, AZ KLINA, Belgium; ⁹Department of Laboratory Medicine, University Hospitals Leuven, Belgium; ¹⁰Department of Development and Regeneration, KU Leuven, Belgium; ¹¹Faculty of Health, University of Plymouth, United Kingdom; ¹²Center of Biostatistics and Statistical bioinformatics, Leuven, Belgium

Background and aims: Women with a history of gestational diabetes (GDM) are at higher risk of developing type 2 diabetes (T2DM) postpartum. The 2-hour oral glucose tolerance test (OGTT) is the preferred method to screen for glucose intolerance in early postpartum, while the clinical value of the 1-hour value on the OGTT remains unclear. We aimed to evaluate the predictive value of the 1-hour OGTT glucose level in early postpartum for the development of T2DM in women with a history of GDM.

Materials and methods: This is a secondary analysis of a multi-center randomized controlled trial (MELINDA), which evaluated the effectiveness of a mobile-based lifestyle intervention in early postpartum in women with prediabetes after a pregnancy complicated by GDM (1). Glucose tolerance was assessed using a 75-gram OGTT at 12 months postpartum. Women were categorized based on their 1-hour glucose value during the OGTT at 3 months postpartum, following recent guidelines from the International Diabetes Federation (2). A value of ≥155 mg/dl (8.6 mmol/l) was used to indicate an increased risk of future T2DM. In addition, a 1-hour value of ≥209 mg/dl (11.6 mmol/l) is diagnostic for diabetes.

Results: Of the 166 women with prediabetes in early postpartum based on the 2-hour OGTT, 106 women (63.9%) had a 1-hour glucose value ≥155 mg/dl at baseline. All 8 (4.8%) cases of T2DM diagnosed at 12 months postpartum occurred in the high risk group (glycemia ≥155 mg/dl), compared to none in the <155 mg/dl group (P = 0.029). Additionally, any form of prediabetes or T2DM was significantly more prevalent in the high risk group compared to those with lower values [65/106 (61.3%) vs. 26/60 (43.8%), P = 0.025]. At 12 months, 21 women had a 1-hour value ≥209 mg/dl, of whom only 5 were diagnosed with T2DM based on the 2-hour value on the OGTT according to the ADA guidelines.

Conclusion: In this high-risk cohort of women with a recent history of GDM, a 1-hour glucose value ≥155 mg/dl during early postpartum OGTT predicted all cases of T2DM diagnosed at 12 months postpartum and identified more women with T2DM at 1 year postpartum compared to the 2h glucose value on the OGTT. These findings support the use of the 1-hour post-load glucose measurement as a valuable early marker for identifying women at increased metabolic risk after a recent history of GDM.

References: 1. Minschart, C. et al. Effectiveness of a blended mobile-based lifestyle intervention in women with glucose intolerance after a recent history of gestational diabetes (MELINDA): a 1-year, prospective, multicentre, randomised controlled trial. EClinicalMedicine 70, (2024).2. Bergman, M. et al. International Diabetes Federation Position Statement on the 1-hour post-load plasma glucose for the diagnosis of intermediate hyperglycaemia and type 2 diabetes. Diabetes Research and Clinical Practice vol. 209. (2024)

Keywords: Gestational diabetes, diabetes, risk prediction, oral glucose test, postpartum