Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, British Columbia, Canada; Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada.
BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada; Department of Dermatology and Skin Science, University of British Columbia, Vancouver, British Columbia, Canada.
Am J Clin Nutr. 2024 Oct;120(4):973-983. doi: 10.1016/j.ajcnut.2024.07.034. Epub 2024 Aug 10.
Dietary Reference Intake (DRI) Recommendations for total sulfur amino acids (TSAAs; methionine + cysteine) during pregnancy are based on factorial calculations using data from adult males. To date, no data exist on TSAA requirements obtained directly during pregnancy.
The objective of this study was to examine whether TSAA requirements during early (11-20 wk) and late (31-40 wk) gestation in healthy females with singleton pregnancies are different than current recommendations, and different between early and late gestation using the indicator amino acid oxidation (IAAO) technique.
Twenty-five females 20-40 y with a healthy singleton pregnancy were studied using the IAAO technique in a repeated measures design for a total of 70, 8-h d. On each study day a methionine test intake (range: 0-40 mg⋅kg⋅d) was provided in 8 hourly, isonitrogenous and isocaloric meals with cysteine excluded from the diet. Breath samples were collected at baseline and isotopic steady state of orally provided L-1-C-Phenylalanine for measurement of phenylalanine oxidation. The requirement was determined using biphasic linear regression crossover analysis to identify a breakpoint in CO production, representing the estimated average requirement (EAR).
The TSAA requirement in healthy pregnant participants in early gestation was 11.1 mg⋅kg⋅d {R = 0.79, R = 0.79; 95% confidence interval [CI] (8.9, 13.3 mg⋅kg⋅d)} and 15.0 mg⋅kg⋅d (R = 0.72, R = 0.79; 95% CI [13.0, 17.0 mg⋅kg⋅d]) in late gestation. The difference between confidence intervals of the 2 breakpoints was = -3.9 ± 3.0, and statistically different.
We directly measured TSAA requirements in healthy pregnant mothers, and our findings suggest that requirements are lower than current DRI recommendations of 20 and 25 mg⋅kg⋅d, as the EAR, and Recommended Dietary Allowance, respectively. Late gestation TSAA needs are significantly different and increased 35% compared with early gestation. Recommendations for TSAA intake need to be tailored for gestational stage. This clinical trial was registered at clinicaltrials.gov as NCT04326322.
妊娠期总硫氨基酸（TSAA；蛋氨酸+半胱氨酸）的膳食参考摄入量（DRI）推荐值是基于使用成年男性数据进行的析因计算得出的。迄今为止，尚无关于在妊娠期间直接获得的 TSAA 需求的数据。
本研究的目的是使用指示剂氨基酸氧化（IAAO）技术，检查健康单胎妊娠女性在早期（11-20 周）和晚期（31-40 周）妊娠期间的 TSAA 需求是否与当前推荐值不同，以及早期和晚期妊娠之间的需求是否不同。
25 名 20-40 岁的女性在健康的单胎妊娠中使用 IAAO 技术进行了重复测量设计，总共进行了 70 次、8 小时的研究。在每个研究日，通过 8 小时、等氮和等热量的膳食提供蛋氨酸测试摄入量（范围：0-40mg·kg·d），饮食中不包含半胱氨酸。在基线和口服 L-1-C-苯丙氨酸达到同位素稳态时采集呼吸样本，以测量苯丙氨酸氧化。使用双相线性回归交叉分析确定 CO 产生的断点，代表估计平均需求量（EAR），从而确定 TSAA 的需求量。
在健康的妊娠早期参与者中，TSAA 的需求量为 11.1mg·kg·d{ R = 0.79，R = 0.79；95%置信区间（8.9，13.3mg·kg·d）}和 15.0mg·kg·d（R = 0.72，R = 0.79；95%置信区间（13.0，17.0mg·kg·d））。2 个断点之间的置信区间差值为=-3.9±3.0，且具有统计学差异。
我们直接测量了健康孕妇的 TSAA 需求量，我们的研究结果表明，需求量低于当前的 DRI 推荐值 20 和 25mg·kg·d，分别作为 EAR 和推荐膳食摄入量。与早期妊娠相比，晚期妊娠的 TSAA 需求量显著增加了 35%。TSAA 摄入量的推荐值需要根据妊娠阶段进行调整。本临床试验在 clinicaltrials.gov 注册，编号为 NCT04326322。
