Background
Prolonged damage of the liver can cause scar tissue formation, which ultimately replaces healthy liver tissue and results in chronic damage (cirrhosis). People with cirrhosis often suffer loss of muscle mass and muscle strength. Therefore, physical exercise may be beneficial to people with cirrhosis.
Review question
We investigated the beneficial and harmful effects of physical exercise compared with sham exercise (for example, supervised relaxation sessions) or no exercise for people with cirrhosis.
Search date
February 2018.
Study funding sources
None of the included trials received industry funding or support from the pharmaceutical or device industry.
Study characteristics
We included six randomised clinical trials (where people are randomly allocated to one of two groups) with 173 participants. All participants had cirrhosis. Interventions consisted of different types of exercise including bicycling, treadmill walking, and weight lifting. Programmes were home-based or supervised and lasted between eight and 14 weeks.
Key results
Physical exercise did not seem to affect mortality (death), side effects or quality of life.
Quality of the evidence
Overall, the evidence for the effect of physical exercise was of low or very low quality. Factors that downgraded the quality of the evidence included lack of trials with a low risk of bias, small trials, and not similar results across trials.
Read the full abstract
Loss of muscle mass and muscle weakness are common complications to cirrhosis and are associated with increased morbidity and mortality. Therefore, physical exercise may benefit people with cirrhosis.
Objectives
To assess the beneficial and harmful effects of physical exercise versus sham exercise or no exercise for people with cirrhosis.
Search strategy
We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, and three other databases, including manual searches through reference lists, abstracts, and presentations at conferences and meetings, Google Scholar, and online trial registers in February 2018.
Selection criteria
We included randomised clinical trials regardless of publication status or language. Inclusion criteria were cirrhosis irrespective of the aetiology or stage. Interventions were physical exercise compared with sham exercise or no intervention.
Data collection and analysis
Three review authors independently extracted data. We undertook meta-analyses and presented results using risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, both with 95% confidence intervals (CI) and I2 values as markers of imprecision and heterogeneity. We assessed bias control using the Cochrane Hepato-Biliary Group domains and determined the credibility of the evidence using GRADE.
Main results
We included six randomised clinical trials with 173 participants. All participants had Child-Pugh stage A or B cirrhosis. The intervention groups participated in eight to 14 weeks of physical exercise (aerobic: three trials; resistance: one trial; or aerobic plus resistance training: two trials). Control groups underwent sham exercise (supervised relaxation: one trial) or no intervention (five trials). None of the 89 participants allocated to exercise versus two of 84 participants in the control group died (RR 0.19, 95% CI 0.01 to 3.73; moderate-quality evidence). The cause of death was acute-on-chronic liver disease for both participants. Nine participants in the exercise group and 13 in the control group experienced serious adverse events (RR 0.61, 95% CI 0.19 to 1.94; low-quality evidence).
Physical exercise showed no beneficial or detrimental effect on health-related quality of life assessed by the Chronic Liver Disease Questionnaire (MD 0.11, 95% CI –0.44 to 0.67; low-quality evidence). Likewise, physical exercise had no clear effect on physical fitness measured by peak exercise oxygen uptake (MD 0.3 mL/kg/minute, 95 % CI –2.74 to 3.35; low-quality evidence) and Six-Minute Walk Test (MD 56.06 min, 95% CI –9.14 to 121.26; very low-quality evidence). Physical exercise showed no clear effect on mid-thigh circumference (MD 1.76 cm, 95% CI –0.26 to 3.77; low-quality evidence), but showed an increase in mid-arm circumference (MD 2.61 cm, 95% CI 0.36 to 4.85; low-quality evidence).
Authors' conclusions
We found no clear beneficial or harmful effect of physical exercise on mortality, morbidity, or health-related quality of life. Further evidence is needed to evaluate the beneficial and harmful effects of physical exercise on clinical outcomes.
