サルコペニアの在宅高齢女性に対する運動とアミノ酸投与

サルコペニアの在宅高齢女性に対する運動とアミノ酸投与の効果をみた日本のRCTを紹介します。

Hun Kyung Kim, et al: Effects of Exercise and Amino Acid Supplementation on Body Composition and Physical Function in Community-Dwelling Elderly Japanese Sarcopenic Women: A Randomized Controlled Trial. Journal of the American Geriatrics Society Article first published online: 5 DEC 2011 DOI: 10.1111/j.1532-5415.2011.03776.x

75歳以上のサルコペニアと診断された在宅高齢女性を対象に、運動＋アミノ酸群、運動群、アミノ酸群、健康教育（コントロール）群の4群に分けて、運動は1回60分、週2回、アミノ酸はロイシンを多く含む必須アミノ酸3gを1日2回の介入を3ヵ月間行いました。

結果ですが、歩行速度は介入した3群いずれも有意に改善、下肢筋肉量は運動＋アミノ酸群と運動群で改善、膝伸展筋力は運動＋アミノ酸群のみ改善しました。下肢筋肉量と膝伸展筋力改善のオッズ比は、運動＋アミノ酸群と健康教育群で比べて4.89（95％信頼区間：1.89–11.27）でした。

サルコペニアの在宅高齢女性に対する運動とアミノ酸投与の併用で筋力、筋肉量、歩行速度のすべてに改善を認めました。健常者ではアミノ酸投与の併用はあまり効果がないという報告も少なくありませんが、サルコペニアの場合には運動は当然ですが、アミノ酸投与の併用が望ましいといえます。

サルコペニアの在宅高齢女性が対象ですので、入院リハを行っているサルコペニアの女性や男性にも有効かどうかは別の検証が必要です。それでも臨床ではアミノ酸投与（ジョグメイトプロテインゼリーやペムパルアクティブでよいと思いますが）をリハに併用したほうがよいのではと考えます。

Objectives: To evaluate the effectiveness of exercise and amino acid supplementation in enhancing muscle mass and strength in community-dwelling elderly sarcopenic women.

Design: Randomized controlled trial.

Setting: Urban community in Tokyo, Japan.

Participants: One hundred fifty-five women aged 75 and older were defined as sarcopenic and randomly assigned to one of four groups: exercise and amino acid supplementation (exercise + AAS; n = 38), exercise (n = 39), amino acid supplementation (AAS; n = 39), or health education (HE; n = 39).

Intervention: The exercise group attended a 60-minute comprehensive training program twice a week, and the AAS group ingested 3 g of a leucine-rich essential amino acid mixture twice a day for 3 months.

Measurements: Body composition was determined using bioelectrical impedance analysis. Data from interviews and functional fitness parameters such as muscle strength and walking ability were collected at baseline and after the 3-month intervention.

Results: A significant group × time interaction was seen in leg muscle mass (P = .007), usual walking speed (P = .007), and knee extension strength (P = .017). The within-group analysis showed that walking speed significantly increased in all three intervention groups, leg muscle mass in the exercise + AAS and exercise groups, and knee extension strength only in the exercise + AAS group (9.3% increase, P = .01). The odds ratio for leg muscle mass and knee extension strength improvement was more than four times as great in the exercise + AAS group (odds ratio = 4.89, 95% confidence interval = 1.89–11.27) as in the HE group.

Conclusion: The data suggest that exercise and AAS together may be effective in enhancing not only muscle strength, but also combined variables of muscle mass and walking speed and of muscle mass and strength in sarcopenic women.