透析患者への蛋白同化ステロイド

透析患者への経口蛋白同化ステロイドの効果をみた論文を紹介します。

Ouppatham Supasyndh, et al. Effect of Oral Anabolic Steroid on Muscle Strength and Muscle Growth in Hemodialysis Patients. Clinical Journal of the American Society of Nephrology, Published online before print November 2012, doi: 10.2215/​CJN.00380112

リサーチクエスチョンは以下の通りです。

P：透析患者に
I：オキシメトロン（経口蛋白同化ステロイド）を24週間投与すると
C：プラセボ投与と比較して
O：筋肉量と筋力が増加する
D：ランダム化比較試験

抄録しか読めていませんが、オキシメトロン投与群で除脂肪体重と握力は有意に増加し、脂肪は有意に減少しました。副作用として肝酵素はオキシメトロン投与群で有意に上昇しましたが、正常値の3倍を超えた人数には有意差がありませんでした。以上よりオキシメトロンで筋肉量、筋力は増加するが肝障害を認めるという結論です。

透析患者ではサルコペニアを認めることが多いので、筋肉量、筋力を改善できる介入は重要です。ただ、副作用として肝障害がでますし、長期の副作用はわかりませんので、ルーチンで経口蛋白同化ステロイドを使用するわけにはいかないかと思います。やはり高蛋白食＋筋トレ・有酸素運動が基本でしょうか。

Summary

Background and objectives Sarcopenia is common in hemodialysis patients. This study examined whether the anabolic steroid oxymetholone improves muscle mass and handgrip strength in hemodialysis patients and possible mechanisms that might engender such changes.

Design, setting, participants, & measurements Forty-three eligible hemodialysis patients were randomly assigned to ingest oxymetholone or placebo for 24 weeks. Body composition, handgrip strength, and quality of life were measured during the study. Muscle biopsies were performed and analyzed for mRNA levels for myostatin, IGF-I, IGF binding proteins, and myosin heavy chains and protein expression. Muscle fiber types and diameter were assessed by reduced nicotinamide–adenine dinucleotide staining.

Results There was a significantly greater increase in fat-free mass and handgrip strength and decrease in fat mass in the oxymetholone compared with the placebo group. Moreover, compared with baseline values, patients given oxymetholone exhibited an increase in fat-free mass, handgrip strength, physical functioning scores, and type I muscle fiber cross-sectional area and a decrease in fat mass, whereas patients receiving placebo did not undergo changes. There was a significantly greater increase in muscle mRNA levels for myosin heavy chain 2×, IGF-I, and IGF-II receptor with oxymetholone treatment than placebo. Liver enzyme rose significantly in the oxymetholone group, but the number of values greater than three times the upper limit of normal were not different between these groups.

Conclusions In hemodialysis patients, ingesting oxymetholone was associated with an increase in fat-free mass, handgrip strength, and muscle mRNA levels for several growth factors and a decrease in fat mass, but it also induced liver injury.