(P07-036-23) Pre-Pregnancy Inflammatory and Insulinemic Dietary Patterns and Risk of Gestational Diabetes Mellitus: A Prospective Cohort Study of 14,750 Women

Objectives: Inflammation and hyperinsulinemia were implicated in the pathogenesis of gestational diabetes mellitus (GDM). The role of inflammatory and insulinemic diets with GDM risk was still less investigated. We aimed to examine the associations between pre-pregnancy inflammatory and insulinemic diets based on validated diet quality indices and GDM risk.

Methods: Our study included 14,750 women in the Nurses’ Health Study II who reported at least one incident singleton pregnancy. Pre-pregnancy adherence to the empirical dietary inflammatory pattern (EDIP) and empirical dietary index for hyperinsulinemia (EDIH) scores was measured using previously validated methods based on diet information collected by FFQs every 4 years. Incident first-time GDM was ascertained from a self-reported physician diagnosis, which was previously validated by review of medical records. We used log-binomial models with generalized estimating equations to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for associations of pre-pregnancy EDIP/EDIH (quintiles) with incident GDM risk, adjusting for major confounders including pre-pregnancy body mass index (BMI).

Results: In 20,387 pregnancies over 10 years of follow-up, 833 reported GDM. Women with higher pre-pregnancy EDIP and EDIH scores had a higher risk of GDM in multivariable-adjusted models: compared with the lowest quintile, RRs (95% CIs) for increasing quintiles were 1.22 (0.97, 1.53), 1.22 (0.97, 1.54), 1.53 (1.23, 1.92), and 1.72 (1.38, 2.14) for EDIP; 1.27 (1.00, 1.62), 1.36 (1.07, 1.72), 1.56 (1.23, 1.97), and 2.03 (1.62, 2.54) for EDIH (both P linear trend < 0.001). The associations were attenuated after further adjustment for pre-pregnancy BMI, but, remained significant. These associations did not change materially after the adjustment for other diet quality indices, including the Alternate Healthy Eating Index and Alternate Mediterranean Diet Index.

Conclusions: In a large US cohort of predominantly white women, those with greater intake of proinflammatory and hyperinsulinemic diets in pre-pregnancy had a higher risk of developing GDM.

Funding Sources: Funding from NIH which supported Dr. Zhang and Nurses’ Health Study II. Dr. Tobias was supported by American Diabetes Association.