INRA, UNH, Unité de Nutrition Humaine, CRNH Auvergne, Université Clermont Auvergne, Clermont-Ferrand, France.
INRA, UNH, Unité de Nutrition Humaine, CRNH Auvergne, Université Clermont Auvergne, Clermont-Ferrand, France.
Nutrition. 2018 Jun;50:66-73. doi: 10.1016/j.nut.2017.11.004. Epub 2017 Nov 27.
High-fat high-sucrose diet (HFHS) overfeeding is one of the main factors responsible for the increased prevalence of metabolic disorders. Elevated levels of branched-chain amino acids (BCAAs) have been associated with metabolic dysfunctions, including insulin resistance (IR). The aim of this study was to elucidate whether elevated BCAA levels are the cause or the consequence of IR and to determine the mechanisms and tissues involved in such a phenotype.
We performed a 2-mo follow-up on minipigs overfed an HFHS diet and focused on kinetics fasting and postprandial (PP) BCAA levels and BCAA catabolism in key tissues.
The study of the fasting BCAA elevation reveals that BCAA accumulation in the plasma compartment is well correlated with IR markers and body weight. Furthermore, the PP excursion of BCAA levels after the last HFHS meal was exacerbated when compared with that of the first meal, suggesting a reduced amino acid oxidation potential. Although only minor changes in BCAA metabolism were observed in liver, muscle, and the visceral adipose tissue, the oxidative deamination potential of the subcutaneous adipose tissue was blunted after 60 d of HFHS feeding.
To our knowledge, the present results demonstrated for the first time in a swine model of obesity and IR, the existence of a phenotype related to high-circulating BCAA levels and metabolic dysregulation. The oxidative BCAA capacity reduction specifically in the subcutaneous adipose tissue emerges, at least in the present swine model, as the more plausible metabolic explanation for the elevated blood BCAA phenotype.
高脂肪高蔗糖饮食（HFHS）过度喂养是导致代谢紊乱患病率增加的主要因素之一。支链氨基酸（BCAA）水平升高与代谢功能障碍有关，包括胰岛素抵抗（IR）。本研究旨在阐明 BCAA 水平升高是 IR 的原因还是结果，并确定涉及这种表型的机制和组织。
我们对 HFHS 饮食过量的小型猪进行了 2 个月的随访，重点研究了空腹和餐后（PP）BCAA 水平的动力学以及关键组织中的 BCAA 分解代谢。
研究发现，空腹时 BCAA 的升高与 IR 标志物和体重密切相关。此外，与第一餐相比，最后一餐 HFHS 餐后的 BCAA 水平餐后升高更加明显，表明氨基酸氧化能力降低。尽管肝脏、肌肉和内脏脂肪组织中观察到 BCAA 代谢的变化很小，但在 HFHS 喂养 60 天后，皮下脂肪组织的氧化脱氨潜力减弱。
据我们所知，本研究首次在肥胖和 IR 的猪模型中证明了存在与高循环 BCAA 水平和代谢失调相关的表型。至少在本猪模型中，皮下脂肪组织中 BCAA 的氧化能力降低，是对升高的血液 BCAA 表型的更合理的代谢解释。
