Metabolomic biomarkers and novel dietary factors associated with gestational diabetes in China.

Introduction: Gestational diabetes mellitus (GDM) is impaired glucose tolerance first recognised during pregnancy; its development is associated with many adverse outcomes. Mechanisms of GDM development are not fully elucidated and few studies have used Chinese participants.

Objectives: The aim of this study was to investigate the maternal metabolome associated with GDM in a Chinese population, and explore the relationship with maternal diet.

Methods: Ninety-three participants were recruited at 26-28 weeks' gestation from Chongqing, China. Maternal urine, serum, and hair metabolomes were analysed using gas and liquid chromatography-mass spectrometry. Dietary intake was assessed using a 96-item food frequency questionnaire.

Results: Of the 1064 metabolites identified, 73 were significantly different between cases and controls (P < 0.05), but only 2-aminobutyric acid had both a p- and q-value < 0.05. A "snack-based-dietary-pattern" was associated with an increased likelihood of GDM (odds ratio 2·1; 95% confidence interval 1.1-3.9). The association remained significant after adjustment for calorie intake but not food volume.

Conclusion: This study provides a comprehensive characterization of the maternal metabolome. The snack-based dietary pattern associated with GDM suggests that timing and frequency of consumption are important factors in the relationship between maternal diet and GDM.