Despite the role of branched-chain amino acids (BCAAs) in physiological processes such as nutrient signaling and protein synthesis, there is ongoing debate about the link between circulating BCAAs and insulin resistance (IR) in various populations. In healthy women, IR mildly increases during pregnancy, while both BCAAs and markers of BCAA catabolism decrease, indicating that fetal growth is being prioritized. Exercise reduces IR in non-pregnant adults, but less is known about the effect of exercise during pregnancy in women with obesity on IR and BCAA breakdown. The aim of this study was to determine the effect of a moderate intensity exercise intervention during pregnancy on maternal circulating BCAAs and markers of BCAA catabolism (short-chain acylcarnitines (ACs)), and their associations with IR. Healthy obese (n=80, mean±SD; BMI: 36.9±5.7 kg/m²) pregnant women were randomized into an exercise (n=40, aerobic/resistance 3x/week, ~13 weeks until birth) or a non-exercise control (n=40) group. Blood was collected at 12.2±0.5 and 36.0±0.4 gestation weeks and analyzed for BCAA-derived acylcarnitine concentrations as markers of BCAA breakdown toward oxidative pathways, and glucose and insulin concentrations [updated homeostatic model assessment of IR (HOMA2-IR)]. After adjusting for HOMA2-IR, there were no interaction effects of group by time. In addition, there was a main positive effect of time on HOMA2-IR (12 weeks: 2.3±0.2, 36 weeks: 3.0±0.2, P=0.003). A moderate intensity exercise intervention during pregnancy in women with obesity was not associated with changes in BCAA-derived ACs vs. standard of care. The decrease in BCAA-derived ACs throughout gestation could not be explained by IR.

中文翻译：

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肥胖孕妇的运动训练不会影响支链氨基酸分解代谢的标志

尽管支链氨基酸（BCAAs）在诸如营养信号和蛋白质合成等生理过程中发挥着作用，但关于循环BCAA与各种人群中胰岛素抵抗（IR）之间的联系仍存在争议。在健康女性中，怀孕期间IR轻度升高，而BCAA和BCAA分解代谢的标志物均降低，表明胎儿的生长被优先考虑。运动可降低非怀孕成年人的IR，但对于肥胖妇女怀孕期间运动对IR和BCAA分解的影响知之甚少。这项研究的目的是确定怀孕期间进行中等强度的运动干预对孕妇循环中的BCAA和BCAA分解代谢标志物（短链酰基肉碱（AC））的影响以及它们与IR的关系。健康肥胖者（n = 80，平均值±SD; BMI：36.9±5.7 kg / m²）孕妇被随机分为运动组（n = 40，有氧/抵抗力3x /周，出生前约13周）或非运动对照组（n = 40）。在妊娠12.2±0.5周和36.0±0.4周时采集血液，分析BCAA衍生的酰基肉碱浓度，作为BCAA向氧化途径分解的标志物，以及葡萄糖和胰岛素浓度[更新的IR稳态模型评估（HOMA2-IR）]。调整HOMA2-IR后，按时间分组没有交互作用。此外，时间对HOMA2-IR具有主要的积极影响（12周：2.3±0.2，36周：3.0±0.2，P = 0.003）。肥胖妇女在怀孕期间进行中等强度的运动干预与BCAA衍生的AC相对于护理标准的变化无关。IR无法解释整个妊娠过程中BCAA衍生AC的减少。