慢性人工透析患者における透析時の経口摂取と筋トレの効果

慢性人工透析患者における透析時の経口摂取と筋トレの効果を見た論文を紹介します。

Jie Dong MD, Mary B. Sundell, Lara B. Pupim, Pingsheng Wu, Ayumi Shintani, and T. Alp Ikizler. The Effect of Resistance Exercise to Augment Long-term Benefits of Intradialytic Oral Nutritional Supplementation in Chronic Hemodialysis Patients. Journal of Renal Nutrition, Article in Press. doi:10.1053/j.jrn.2010.03.004

慢性人工透析患者を対象に、介入群では透析時の経口摂取＋透析前のレッグプレス12回を3セット、対照群は透析時の経口摂取のみをそれぞれ6ヶ月間実施というランダム化比較試験です。

一次アウトカムは除脂肪体重（LBM）でみましたが、介入群と対照群で統計学的な有意差はありませんでした。二次アウトカム（筋力、栄養指標）にも統計学的有意差はありませんでした。

ただし、両群あわせると体重とレッグプレスの1RMは、介入前と介入後（3か月後、6か月後）で比較すると有意に改善していました。

透析時の経口摂取は体重増加と筋力増強に有用であるが、それに筋トレ（透析前のレッグプレス12回を3セット）を追加してもさらなる効果は認めないという結論です。

ただし、32人中22人しか6カ月間の介入ができなかったこと（脱落率が高い）、両群をあわせるというRCTではめったにやらない統計学的解析をしていることなどを考慮すると、質の低いRCTだと思います。筋トレの明らかな効果は認めませんでしたが、これで慢性人工透析患者に筋トレは不要とは言えないと考えます。

Abstract

Background
Resistance exercise combined with intradialytic oral nutrition (IDON) supplementation improves net protein balance in the acute setting in chronic hemodialysis patients. We hypothesized that combination of long-term resistance exercise and IDON would improve markers of muscle mass and strength further compared with IDON alone.

Methods
Thirty-two participants (21 male; mean age, 43 ± 13 years) on chronic hemodialysis were randomly assigned to IDON plus resistance exercise (NS + EX), or IDON (NS) alone for 6 months. IDON consisted of a lactose-free formula consisting of protein, carbohydrate, and fat. Three sets of 12 repetitions of leg-press were completed before each dialysis session in the NS + EX arm. Primary outcome measurement was lean body mass. Muscle strength and other nutritional parameters were measured as secondary outcomes.

Results
Of 32 participants, 22 completed the 6-month intervention. There were no statistically significant differences between the study interventions with respect to changes in lean body mass and body weight, when comparing NS + EX to NS. There were also no statistically significant differences in any of the secondary outcomes measured in the study. Body weight (80.3 ± 16.6 kg, 81.1 ± 17.5 kg, and 80.9 ± 18.2 kg at baseline, month 3, and month 6, respectively; P = .02) and 1-repetition maximum (468 ± 148 lb, 535 ± 144 lb, and 552 ± 142 lb, respectively; P = .001) increased statistically significantly during the study for all patients combined.

Conclusion
This study did not show further benefits of additional resistance exercise on long-term somatic protein accretion above and beyond nutritional supplementation alone. When both treatments groups were combined, body weight and muscle strength improved during the study.