Inverse Association of Total Polyphenols and Flavonoids Intake and the Intake from Fruits with the Risk of Gestational Diabetes Mellitus: A Prospective Cohort Study

Background & Aims: Emerging evidence has shown the inverse association between dietary polyphenols intake and type 2 diabetes mellitus risk, however, few studies focus on the prospective effects of polyphenols on gestational diabetes mellitus (GDM). Thus, the aim was to evaluate whether higher polyphenols intake and the intake from fruits and vegetables was correlated to a lower risk of GDM.

Methods: Dietary intake of polyphenols of women with a singleton pregnancy and without any history of diabetes were obtained by a validated food frequency questionnaire from Tongji Maternal and Child Health Cohort study. Oral glucose tolerance tests were conducted at 24-28 weeks to screen for GDM. Logistic regression models were used to evaluate the association between dietary intake of polyphenols, and the results were presented as odds ratios (ORs) with 95% confidence interval (CIs). Generalized linear models were adopted to determine the association of polyphenols intake with blood glucose concentrations, and the results were presented as coefficients (β) with 95% CIs.

Results: 185 (8.3%) of 2231 pregnant women were diagnosed with GDM. The intake of total polyphenols was 319.9 (217.8-427.0) mg/d, and the intake from fruits and vegetables was 201.6 (115.3-281.8) mg/d and 63.2 (41.1-92.7) mg/d, respectively. Compared with the lowest quartile, the adjusted ORs (95% CIs) of GDM risk for women with the highest quartile of total polyphenols and flavonoids intake was 0.55 (0.30, 0.99), and 0.57 (0.32, 0.99). The adjusted ORs (95% CIs) of GDM risk was 0.55 0.51 (0.30, 0.87) (P = 0.017) for polyphenols from fruits, 0.58 (0.34, 0.99) (P = 0.038) for flavonoids from fruits, and 0.62 (0.38, 1.00) (P = 0.065) for anthocyanidins from fruits comparing the highest versus lowest quartile. In addition, each 100 mg increase of total polyphenols and polyphenols from fruits was associated with 0.054 (0.008, 0.096) (P = 0.021) and 0.061 (0.012, 0.109) (P = 0.015) decrease in 2-h post-load blood glucose. No significant association was found between total polyphenols from vegetables intake and the risk of GDM.

Conclusions: Higher dietary intake of total polyphenols and flavonoids and the intake from fruits was associated with lower GDM risk. This study was registered at clinicaltrials.gov as NCT03099837.