Researchers recommend that physicians prescribe exercise for patients with nonalcoholic fatty liver disease

Getting fit may be just the trick to slowing the progression of nonalcoholic fatty liver disease (NAFLD), which is now the most common cause of abnormal liver function in the United States, according to a study published in Hepatology.

Researchers determined that patients with greater disease activity and severity also had worse cardiorespiratory fitness. Overall, the 37 patients in the study with varying degrees of severity of NAFLD had levels of cardiorespiratory fitness, muscle strength, body composition and physical activity that were below average.

It would appear rational and prudent for health care providers to recommend exercise training to improve health-related fitness as an integral role in the care of patients with NAFLD, wrote the authors, who noted that NAFLD is referred to as the hepatic manifestation of metabolic syndrome, a condition in which exercise makes a positive difference.

Despite their recommendation, the authors did admit that the small sample size of their study limited the strength of their conclusion. However, they maintained that the objective findings of the study demonstrated the potential clinical relevance of exercise for patients with NAFLD and the importance of further study on the effect of exercise in the progression of the condition.

The study which is the first to compare objective measurements of fitness in patients with NAFLD, recruited 18 men and 19 women from the Non-alcoholic Steatohepatitis (NASH) Clinical Research Network NAFLD Database at the University of California, San Francisco. Health-related fitness was assessed by measurements of cardiorespiratory fitness, muscle strength, body composition and physical activity. Liver histology was used to classify severity of liver disease by steatosis, fibrosis stage, necroinflammatory activity and diagnosis of NASH.

More than half of the patients (51%) were diagnosed as having metabolic syndrome; 84% were classified as overweight or obese; and 97% had excess body fat. Less than 20% of the patients with mild or moderate steatosis and 33% of those with severe steatosis reported meeting the Surgeon General’s recommendations for physical activity.

Researchers did not find many significant differences between patients in different disease severity groups, with the exception of peak VO2 levels; this measure of cardiorespiratory fitness was significantly higher in patients with a NAFLD Activity Score of less than 4 compared with those with a score of more than 5 and in patients without NASH compared with those with the condition.