Association of free fatty acid in first trimester with the risk of gestational diabetes mellitus: a nested case-control study

Abstract

Accumulating evidence shows that free fatty acids (FFA) are associated with gestational diabetes mellitus (GDM). However, most of the studies focus on a few specific types of FFA, such as α-linolenic acid (C18:3n3) and Arachidonic acid (C20:4n6) or a total level of FFA. This study aimed to test the association between a variety of FFAs during the first trimester and the risk of GDM. The participants came from the Zhoushan Pregnant Women Cohort (ZWPC). A 1:2 nested case-control study was conducted: fifty mothers with GDM were matched with 100 mothers without GDM by age, pre-pregnancy body mass index (BMI), month of oral glucose tolerance test (OGTT) and parity. Thirty-seven FFAs (including 17 saturated fatty acids (SFA), 8 monounsaturated fatty acids (MUFA), 10 polyunsaturated fatty acids (PUFA) and 2 trans fatty acids (TFA)) in maternal plasma during the first trimester were tested by Gas Chromatography–Mass Spectrometry (GC-MS). Conditional logistic regression models were performed to assess the associations of FFA with the risk of GDM. Nine FFAs were respectively associated with an increased risk of GDM (P < 0.05), and four FFAs were respectively associated with a decreased risk of GDM (P < 0.05). SFA risk score was associated with a greater risk of GDM (OR = 1.34, 95% CI: 1.12–1.60), as well as UFA risk score (OR = 1.26, 95% CI: 1.11–1.44), MUFA risk score (OR = 1.70, 95%CI: 1.27–2.26), PUFA risk score (OR = 1.32, 95%CI: 1.09–1.59) and TFA risk score (OR = 2.51, 95%CI: 1.23–5.13). Moreover, joint effects between different types of FFA risk scores on GDM were detected. For instance, compared with those with low risk scores of SFA and UFA, women with high risk scores of SFA and UFA had the highest risk of GDM (OR = 8.53, 95%CI: 2.41–30.24), while the Odds ratio in those with a low risk score of SFA and high risk score of UFA and those with a high risk score of SFA and low risk score of UFA was 6.37 (95%CI:1.33– 30.53) and 4.25 (95%CI: 0.97–18.70), respectively. Maternal FFAs during the first trimester were positively associated with the risk of GDM. Additionally, there were joint effects between FFAs on GDM risk. Elevated FFA levels in the first trimester increased the risk of GDM.