運動可能對非酒精性脂肪肝臟疾病病患有益

作者：Laurie Barclay, MD  
出處：WebMD醫學新聞

July 21, 2009 — 一項發表在7月肝臟學期刊的研究結果顯示，運動可能對非酒精性肝臟疾病（NAFLD）病患有益，且獨立於體重變化之外。
　　
　　澳洲雪梨大學與Wsetmead醫院的Alexis St. George寫到，非酒精性脂肪肝臟疾病以肝臟酵素升高、軀幹肥胖、以及胰島素抗性表現，這種疾病越來越常見。目前並沒有關於運動量改變對於這群病患效應的相關研究報告。
　　
　　研究團隊針對141位NAFLD病患進行為期3個月、以行為改變為基礎，對運動量及代謝相關指數的效應，這些病患前瞻性地收納分派為低或中度生活型態介入或是控制組。以一項已確效的工具量測運動量，同時使用YMCA周期肌力計評估身體健康情況。所有介入組受試者都接受個人化的諮詢，以增加運動量。
　　
　　在3個月時的後續追蹤率為96%。相較於控制組的受試者，那些中低度介入組每週增加至少1小時運動量的機會高出9倍。
　　
　　相較於運動量最低的受試者，那些改善、或是維持其運動量至每週150分鐘，以及那些體適能改善的受試者，肝臟酵素與其他代謝指標改善最多。
　　
　　這些好處與減重無關，但與體適能有關。隨著運動量增加超過每週60分鐘，並未觀察到對肝臟酵素之劑量與效應的關聯性。
　　
　　研究團隊寫到，生活模式的諮詢對於改善運動行為有效。維持或是增加運動量提供脂肪肝患者健康上的益處，且獨立於體重變化。
　　
　　這項研究的限制是缺乏運動量的客觀評量。
　　
　　研究團隊的結論是，改善運動量對於罹患NAFLD病患的肝臟酵素、胰島素抗性、以及其他代謝指標有正面效應。這是特別重要的預後，肝臟脂肪已經證實獨立地與所有代謝症候群危險因子相關。這項研究突顯了有肝病的病患若維持不運動或是不再運動（不論是否有減重），將成為代謝症候群的危險因子，且研究顯示運動對非酒精性肝臟疾病病患有益。
　　
　　澳洲全國衛生與醫學研究委員會及澳洲雪梨大學贊助這項研究。本研究作者宣稱沒有相關財務關係。

Physical Activity May Benefit Patients With Nonalcoholic Fatty Liver Disease

By Laurie Barclay, MD
Medscape Medical News

July 21, 2009 — Physical activity may benefit patients with nonalcoholic fatty liver disease (NAFLD) independent of weight changes, according to the results of a study reported in the July issue of Hepatology.

"Nonalcoholic fatty liver disease, characterized by elevated liver enzymes, central obesity, and insulin resistance, is becoming increasingly prevalent," write Alexis St. George, from the University of Sydney and Westmead Hospital in Sydney, Australia. "The effects of changes in physical activity on the metabolic profile of this group have not been reported."

The investigators studied the effect at 3 months of a behavior change–based lifestyle intervention on physical activity and on the metabolic profile of 141 patients with NAFLD who were prospectively enrolled into either a low-intensity or moderate-intensity lifestyle intervention or to a control group. A validated reporting tool was used to measure physical activity, and the YMCA protocol on a cycle ergometer was used to determine physical fitness. All participants in the intervention groups received individualized counseling to increase physical activity.

Follow-up rate for the 3-month evaluation was 96%. Compared with participants in the control group, those in the moderate-intensity and low-intensity intervention groups were 9 times more likely to increase physical activity by at least 1 hour per week.

Compared with patients who were least active, those who improved or maintained their reported physical activity to more than 150 minutes per week and those who improved their objective levels of fitness had the greatest improvements in liver enzymes and other metabolic markers.

These benefits were independent of weight loss and were corroborated by an objective measure of fitness. With incremental increases in physical activity of more than 60 minutes per week, there was no dose-response effect on liver enzymes.

"Lifestyle counseling interventions are effective in improving physical activity behavior," the study authors write. "Maintaining or increasing physical activity provides health benefits for patients with fatty liver, independent of changes in weight."

Limitations of this study include lack of objective measures of change in physical activity.

"Improvements in physical activity can have positive effects on liver enzymes, insulin resistance, and other metabolic parameters in people with NAFLD," the study authors conclude. "This is a particularly important outcome, as liver fat has been shown to correlate independently with all risk factors of the metabolic syndrome....This study highlights the risk of remaining or becoming physically inactive (irrespective of whether weight loss is achieved) on metabolic parameters in patients with liver disease, and demonstrates the importance of physical activity for patients with NAFLD."

The National Health and Medical Research Council of Australia and the Robert W. Storr bequest to the University of Sydney supported this study. The study authors have disclosed no relevant financial relationships.

Hepatology. 2009;50:68-76.