Hagg S A, Adibi S A
Metabolism. 1985 Sep;34(9):813-6. doi: 10.1016/0026-0495(85)90104-0.
Previous studies have suggested increased protein catabolism and altered muscle metabolism in hyperthyroid patients. In this experiment we investigated parameters of protein and leucine metabolism before and after treatment of hyperthyroidism. While confined in a metabolic ward, patients' daily caloric intake was based on the resting energy expenditure and an allowance for 16 hours of light physical activity. We found no significant difference in plasma aminogram and urinary 3-methylhistidine excretion (an index of protein catabolism) before and after treatment. On the other hand, hyperthyroidism appeared to increase the rates of oxidation, turnover, and plasma clearance of endogenous leucine. However, only the 60% increase in the rate of leucine oxidation was statistically significant. We conclude that in spite of increased catabolism, basal levels of branched-chain amino acids are well maintained in plasma of hyperthyroid patients consuming a diet that compensates for their hypermetabolic state.
以往的研究表明，甲状腺功能亢进患者的蛋白质分解代谢增加，肌肉代谢发生改变。在本实验中，我们研究了甲状腺功能亢进治疗前后蛋白质和亮氨酸代谢的参数。患者在代谢病房期间，每日热量摄入基于静息能量消耗以及16小时轻度体力活动的能量消耗。我们发现治疗前后血浆氨基酸谱和尿3-甲基组氨酸排泄（蛋白质分解代谢指标）无显著差异。另一方面，甲状腺功能亢进似乎增加了内源性亮氨酸的氧化、周转和血浆清除率。然而，只有亮氨酸氧化率60%的增加具有统计学意义。我们得出结论，尽管分解代谢增加，但在摄入能补偿其高代谢状态饮食的甲状腺功能亢进患者血浆中，支链氨基酸的基础水平仍能得到良好维持。
