Department of Dietetics and Nutrition, University of Kansas Medical Center, Kansas City, KS, USA.
Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, KS, USA.
J Nutr. 2023 Jan 14;152(12):2708-2715. doi: 10.1093/jn/nxac178.
DHA is an essential omega-3 (ω-3; n-3) fatty acid that has well-established benefits for the fetus. DHA also has the potential to influence the health of the mother, but this area is understudied.
The objective of this secondary analysis was to determine if DHA was related to maternal heart rate (HR) and heart rate variability (HRV) metrics in a large cohort of pregnant women.
In the parent trial (1R01HD086001) eligible participants (≥18 y old, English speaking, carrying a singleton pregnancy, 12-20 wk of gestation) were randomly assigned to consume 200 mg/d or 800 mg/d DHA for the duration of their pregnancy (n = 300). Weight, blood pressure, and magnetocardiograms (MCGs) were collected at 32 wk and 36 wk of gestation (n = 221). Measures of HR and HRV in time-, frequency-, and nonlinear-domains were determined from the isolated maternal MCG. Treatment group and timepoint were examined as predictors in association with HR and HRV metrics using random-intercept mixed-effects ANOVA unadjusted and adjusted models accounting for weight and dietary DHA intake.
Women receiving the higher dose of DHA (800 mg/d) during pregnancy had lower HR, lower sympathetic index, higher vagally mediated HRV indices, and greater HRV complexity when compared with the women who received the lower dose (200 mg/d; all P < 0.05). All the dose relations remained significant even after controlling for the effect of time, maternal weight, and dietary DHA intake.
DHA supplementation increases vagal tone in pregnant women. Longitudinal studies examining the potential link between DHA, enhanced vagal tone, and reported reduction in early preterm birth are warranted.
二十二碳六烯酸（DHA）是一种必需的ω-3（ω-3；n-3）脂肪酸，对胎儿有明确的益处。DHA 还有可能影响母亲的健康，但这方面的研究还很有限。
本二次分析的目的是确定在一个大型孕妇队列中，DHA 是否与母亲的心率（HR）和心率变异性（HRV）指标有关。
在母试验（1R01HD086001）中，符合条件的参与者（≥18 岁，会说英语，怀有单胎妊娠，妊娠 12-20 周）被随机分配在整个孕期内每天服用 200mg 或 800mg DHA（n=300）。在妊娠 32 周和 36 周时采集体重、血压和心磁图（MCG）（n=221）。从孤立的母体 MCG 中确定 HR 和 HRV 的时间、频率和非线性域中的指标。在未经调整和调整体重和膳食 DHA 摄入量的随机截距混合效应方差分析模型中，使用治疗组和时间点作为与 HR 和 HRV 指标相关的预测因子进行检查。
与接受低剂量（200mg/d）DHA 的女性相比，接受高剂量（800mg/d）DHA 的女性在妊娠期间的 HR 更低、交感神经指数更低、迷走神经介导的 HRV 指数更高、HRV 复杂性更高（所有 P<0.05）。即使在控制时间、产妇体重和膳食 DHA 摄入量的影响后，所有剂量关系仍然显著。
DHA 补充增加了孕妇的迷走神经张力。需要进行纵向研究，以检验 DHA、增强的迷走神经张力与报告的早期早产率降低之间的潜在联系。
