サルコペニアのphase IIb研究のデザイン

サルコペニアのphase IIb研究のデザインに関する国際サルコペニアワーキンググループの論文を紹介します。

Chumlea WC, Cesarit M, Evans WJ, Ferrucci L, Fielding RA, Pahor M, Studenski S, Vellas B. Sarcopenia: designing phase IIb trials: international working group on sarcopenia. J Nutr Health Aging. 2011;15(6):450-5.

今までの研究で除脂肪量（fat-free mass）は身体活動や栄養介入によって短期間で反応することがわかっています。しかし、薬物療法では有意な効果を示すことができていません。治療効果、サンプルサイズ、一次アウトカムが適切なサルコペニア研究は少ないのが現状です。

DEXAは除脂肪量の測定に有効ですが、正確かつ信頼できる変化を観察するにはかなりの時間が必要です。臨床、基礎、疫学の研究に有用なサルコペニアの診断方法の確立が必要です。

リハやNSTの臨床ではどんな診断基準であれ、サルコペニアに間違いないという方が少なからずいます。サルコペニア肥満の方を見落としている可能性があるかもしれませんが。正確な定義と診断基準ができるまで何年も待っている猶予は、臨床にはありません。

機能訓練室で運動を行った直後に、サルコペニアに効果的と思われる栄養材を飲む（運動中でも構いませんが）というリハ栄養文化を、早く日本に定着させたいと思っています。

abstract

Sarcopenia is the age-related involuntary loss of skeletal muscle mass and functionality that can lead to the development of disability, frailty and increased health care costs. The development of interventions aimed at preventing and/or treating sarcopenia is complex, requiring the adoption of assumptions and standards that are not well established scientifically or clinically. A number of investigators and clinicians (both from academia and industry) met in Rome (Italy) in 2009 to develop a consensus definition of sarcopenia. Subsequently, in Albuquerque (New Mexico, USA) in 2010, the same group met again to consider the complex issues necessary for designing Phase II clinical trials for sarcopenia. Current clinical trial data indicate that fat-free mass (FFM) parameters are responsive to physical activity/nutritional treatment modalities over short time periods, but pharmacological trials of sarcopenia have yet to show significant efficacy. In order to conduct a clinical trial within a reasonable time frame, groups that model or display accelerated aging and loss of FFM are necessary. Few studies have used acceptable designs for testing treatment effects, sample sizes or primary outcomes that could provide interpretable findings or effects across studies. Dual energy x-ray absorptiometry (DXA) is the measure of choice for assessing FFM, but sufficient time is needed for changes to be detected accurately and reliably. A tool set that would allow clinical, basic and epidemiological research on sarcopenia to advance rapidly toward diagnosis and treatment phases should be those reflecting function and strength.