ロイシンでサルコペニアと2型糖尿病を予防

ロイシンによるサルコペニアと2型糖尿病の予防と治療に関するレビュー論文を紹介します。
Marika Leenders, Luc JC van Loon: Leucine as a pharmaconutrient to prevent and treat sarcopenia and type 2 diabetes. Nutrition Reviews Volume 69, Issue 11, pages 675–689, November 2011, DOI: 10.1111/j.1753-4887.2011.00443.x

ロイシンによるサルコペニアの予防、治療に関してはあちこちで聞きますが、2型糖尿病の予防と治療にも有効な可能性があるということは初めて聞きました。ロイシンには強いインスリンの分泌促進作用があるので、仮説としてはロイシンが2型糖尿病に有効な可能性があります。これは今後の検証が必須ですが。

2型糖尿病の治療目的でロイシンを使用することは、現時点では考えません。ただ、サルコペニアを合併した2型糖尿病患者の場合、運動療法（有酸素運動＋レジスタンストレーニング）、食事療法、必要時は薬物療法に加えて、ロイシン・BCAAを多く含んだアミノ酸製剤や栄養剤を筋トレ直後に摂取するのはよいかもしれません。

Absrtact
Amino acids function as precursors for de novo protein synthesis. In addition, however, they play a key role as nutritional signals that regulate multiple cellular processes. There is ample in vitro and in vivo evidence showing that muscle tissue responds to increases in amino acid availability via signal transduction pathways that are also regulated by insulin, glucagon, growth hormone, and insulin growth factor 1. The increased amino acid availibility results in the upregulation of mRNA translation, thereby increasing muscle protein synthesis, which, in turn, leads to greater net muscle protein accretion. These findings have been particularly pronounced for the amino acid leucine. Furthermore, leucine has the ability to act as a strong insulin secretagogue. Consequently, it has been suggested that leucine represents an effective pharmaconutrient for the prevention and treatment of sarcopenia and type 2 diabetes. In accordance, recent in vivo studies in humans show that free leucine ingestion can reverse the blunted response of muscle protein synthesis to amino acid/protein intake in the elderly. Although short-term studies suggest that leucine supplementation can stimulate muscle mass accretion in the elderly, there are no long-term nutritional intervention studies to confirm this or the other proposed benefits of leucine as a pharmaconutrient.