Synergistic use of 1,5-AG and HbA1c for early prediction of gestational diabetes - capturing BMI-dependent glycemic phenotypes

Q: What was the purpose of combining HbA1c with 1,5-AG in this study?

To evaluate whether the dual use of HbA1c and 1,5-AG improves early prediction of gestational diabetes mellitus and whether predictive performance differs by BMI.

Q: When were HbA1c and 1,5-AG measured, and who was included?

Women had both markers measured before 20 weeks of gestation at two tertiary centers in Japan. Pregnant women aged 18 or older undergoing these measurements were included, excluding those with prepregnancy or overt diabetes.

Q: How did single-marker performance vary with BMI?

In BMI ≥ 25.0 kg/m2, HbA1c outperformed 1,5-AG (AUC 0.776 vs 0.618). In BMI < 25.0 kg/m2, 1,5-AG outperformed HbA1c (AUC 0.704 vs 0.640).

Q: What did the dual-marker model achieve across BMI groups?

The dual-marker approach was superior in both BMI strata (AUC 0.833 and 0.803, respectively) and provided more balanced sensitivity, accuracy, and F1.

Sep 29, 2026

Uploaded by Genevieve

Gestational diabetes mellitus (GDM) shows metabolic heterogeneity that varies with body mass index (BMI). This multicenter retrospective study assessed whether combining hemoglobin A1c (HbA1c) and 1,5-anhydroglucitol (1,5-AG) improves early prediction before 20 weeks and whether accuracy differs across BMI strata. Among 191 women, ROC-based models were compared, including sensitivity, accuracy, and F1 evaluation, to identify BMI-dependent glycemic phenotype capture.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages10

Reading Time25 min

AccessFree to download

Abstract

Purpose

Methods

Results

Conclusion

Introduction

Methods

Study design and participants

Glucose assessment and 75 g OGTT

Archives of Gynecology and Obstetrics (2026) 313:4 [https://doi.org/10.1007/s00404-025-08281-3](https://doi.org/10.1007/s00404-025-08281-3) Synergistic use of 1,5‑AG and HbA1c for early prediction of gestational diabetes: capturing BMI‑dependent glycemic phenotypes ShoTano1,2 · Tatsuo Inamura1,2 · Kazuya Fuma1 · Seiko Matsuo1 · Kenji Imai1 · Satoru Katsuki1 · Yasuyuki Kishigami2 · Hidenori Oguchi2 · Tomomi Kotani3 · Takafumi Ushida1 · Hiroaki Kajiyama1 Received: 2 August 2025 / Accepted: 14 November 2025 © The Author(s) 2025 Abstract Purpose Recognizing metabolic heterogeneity in gestational diabetes mellitus (GDM) and body mass index (BMI)-linked phenotypes, we evaluated whether combining hemoglobin A1c (HbA1c, reflecting fasting glycaemia) and 1,5-anhydroglucitol (1,5-AG, reflecting post-load glucose excursions) improves early prediction and whether performance differs by BMI. Methods In this multicenter retrospective study, pregnant women who had 1,5-AG and HbA1c measured before 20 weeks of gestation at two tertiary centers in Japan were included. Spearman’s correlation was used to assess associations between glycemic markers and glucose levels. Predictive performance for GDM was evaluated using ROC analysis, and stratified analyses were conducted by pre-pregnancy BMI. Results Among 191 participants, 45 (24 . 1%) developed GDM: 35.1 ± 4.9 years, pre-pregnancy BMI 22.9 ± 4.3 kg/m2, and sampling at 14.3 [IQR 14.0–14.7] weeks. HbA1c correlated with fasting glucose (r = 0.35) while 1,5-AG correlated inversely with 2-h glucose (r = − 0.39). They themselves were not significantly correlated (r = − 0.13) . As single predictors, performance depended on BMI: in ≥ 25.0 kg/m2, HbA1c outperformed 1,5-AG (AUC 0.776 vs 0.618); in BMI < 25.0 kg/ m2, 1,5-AG outperformed HbA1c (AUC 0.704 vs 0.640) . In both BMI strata, the dual-marker model was superior (AUC 0.833 and 0.803, respectively) and provided more balanced sensitivity, accuracy, and F1 . Pre-pregnancy BMI correlated positively with fasting plasma glucose (r = 0.47) but not with 1-h or 2-h glucose (r = 0.20 and r = 0.16, respectively), supporting BMI-related metabolic variation. Conclusion Combining 1,5-AG and HbA1c enhances early prediction of GDM by capturing complementary glycemic abnormalities linked to BMI-specific metabolic phenotypes. Keywords 1,5-Anhydroglucitol · Glycemic variability · Pre-pregnancy BMI · Predictive model · Postprandial hyperglycemia * Sho Tano[tano.sho.v4@f.mail.nagoya-u.ac.jp](tano.sho.v4@f.mail.nagoya-u.ac.jp) 1 Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Showa-Ku Tsurumai 65, Nagoya, Aichi 466-8560, Japan 2 Department of Obstetrics, Perinatal Medical Center, Toyota Memorial Hospital, Toyota, Aichi 471-8513, Japan 3 Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan Introduction Gestational diabetes mellitus (GDM) and impaired glucose metabolism during pregnancy are associated with adverse maternal and fetal outcomes, including an increased risk of short- and long-term metabolic disorders in mothersand children [1–4] . According to current diagnostic criteria, GDM is identified when either fasting plasma glucose (FPG) or post-load glucose levels during an oral glucose tolerance test (OGTT) exceed defined thresholds [5, 6] . Asa result, GDM encompasses a spectrum of pathophysiologically distinct phenotypes under a single diagnostic label. In other words, women with elevated fasting glucose and those with postprandial hyperglycemia are classified as having the same disorder despite differing underlying mechanisms of dysglycemia. Obesity is well known to be associated with elevated fasting glucose levels due to increased hepatic glucose production and insulin resistance [7–9] . In contrast, exaggerated post-load glucose excursions are often driven by impaired early-phase insulin secretion and may reflect underlying

FAQs

What was the purpose of combining HbA1c with 1,5-AG in this study?

To evaluate whether the dual use of HbA1c and 1,5-AG improves early prediction of gestational diabetes mellitus and whether predictive performance differs by BMI.

When were HbA1c and 1,5-AG measured, and who was included?

Women had both markers measured before 20 weeks of gestation at two tertiary centers in Japan. Pregnant women aged 18 or older undergoing these measurements were included, excluding those with prepregnancy or overt diabetes.

How did single-marker performance vary with BMI?

In BMI ≥ 25.0 kg/m2, HbA1c outperformed 1,5-AG (AUC 0.776 vs 0.618). In BMI < 25.0 kg/m2, 1,5-AG outperformed HbA1c (AUC 0.704 vs 0.640).

What did the dual-marker model achieve across BMI groups?

The dual-marker approach was superior in both BMI strata (AUC 0.833 and 0.803, respectively) and provided more balanced sensitivity, accuracy, and F1.

Sep 29, 2026

Uploaded by Genevieve