PURPOSE: To explore the associations of erythrocyte polyunsaturated fatty acids (PUFAs) with the risk of gestational diabetes mellitus (GDM) in pregnant women. METHODS: A total of 951 women in mid-pregnancy (20-28 weeks of gestation) were recruited during 2017-2018. Erythrocyte PUFAs were measured by gas chromatography and expressed as a percentage of total fatty acids. A 75 g oral glucose tolerance test was used for GDM diagnosis. Logistic regression and restricted cubic spline models were conducted. RESULTS: Among the 951 pregnant women, 180 were diagnosed with GDM (18.93%). For n-3 PUFAs, each standard deviation (SD) increase in α-linolenic acid (ALA) and docosapentaenoic acid (DPA) was associated with multivariable-adjusted odds ratios (ORs) of 0.789 (95% CI: 0.649, 0.961
P = 0.018) and 0.782 (95% CI: 0.638, 0.957
P = 0.017), respectively. However, the associations became marginally significant after post hoc false-discovery rate (FDR) correction (both P CONCLUSION: Erythrocyte GLA was significantly associated with an increased risk of GDM in pregnant women. Furthermore, we observed for the first time significant non-linear associations of erythrocyte ALA and GLA with GDM risk. CLINICAL TRIAL REGISTRY NUMBER: NCT03023293, 2019-01-11.