Patients with a sedentary lifestyle who engage in routine physical activities lower their risk of nonalcoholic fatty liver disease (NAFLD), say researchers from the University of Sydney.
The lower risk of problems associated with fatty liver was not contingent upon weight loss, but a direct result from the increased aerobic exercise, the study published in the October issue of Hepatology found.
Nonalcoholic fatty liver disease, where fat accumulates in the liver of those people who drink little or no alcohol, can cause inflammation or scarring of the liver with more serious cases, known as nonalcoholic steatohepatitis, possibly progressing to liver failure.
The study, led by Jacob George, M.D. from Westmead Hospital at the University of Sydney, included 19 obese adults who had a body mass index >30 kg/m2 and reported a sedentary lifestyle. Baseline measurements were performed to determine hepatic triglyceride concentration (HTGC) and hepatic lipid saturation index (SI), intramyocellular triglyceride (IMTG) levels, visceral adipose tissue (VAT) or amount of fat stores in the abdomen, cardiorespiratory fitness, blood biochemistry, and measurements for body height and weight. Volunteers either received 4 weeks of aerobic cycling exercise (12 subjects) or a placebo (7 participants), which involved regular stretching.
At the end of the 4-week period, measurements were again taken from each participant. Body weight and body mass index (BMI) remained unchanged, but cardiorespiratory fitness significantly improved in the exercise group versus placebo.
Researchers noted a 21 percent reduction of HTGC and 12 percent VAT volume in those participants who were subject to regular exercise.
"Our data provides the first direct experimental evidence that regular aerobic exercise reduces fatty liver in obesity without concurrent changes in body weight or abdominal fat," explained researchers.