Moderate physical activity does not improve lipoprotein concentrations in obese patients with non-alcoholic fatty liver disease (NAFLD), say researchers. The team found that in these patients, exercise only decreases triglyceride and alanine transaminase (ALT) levels by a small amount.

The study is published in Hepatology, a journal of the American Association for the Study of Liver Diseases.

According to the World Health Organization (WHO), in 2008, 1.5 billion individuals aged 20+ were overweight, and of these, 500 million were considered obese.

NAFLD is a common complication of obesity and can cause inflammation and scarring in the liver as well as liver failure. Earlier studies revealed that regular exercise and weight loss improved metabolic disturbances linked with NALFD.

In this study, Dr. Samuel Klein and his team from the Washington University School of Medicine in St. Louis, Mo., set out to determine how physical activity programs recommended by the Department of Health and Human Services impacted cholesterol, ALT, and triglyceride levels in obese patients with NALFD.

The researchers enrolled 18 obese patients with NAFLD to participate in the study. 12 participants were randomly assigned to the physical activity group and 6 were assigned to the control group. Those in the physical activity group engaged in 30-60 minutes of moderate exercise 5 days per week for 16 weeks.

The team evaluated how much physical exercise affected very low density lipoproteins (VLDL), intrahepatic triglyceride (IHTG), and apolipoprotein B-100 (apoB-100).

The researchers found that physical activity reduced IHTG content by 10%, but did not change body fat percentage or total body weight. Before the exercise program began, total body weight was 103.1 kg vs. 102.9 kg after, and total body fat was 38.9 vs. 39.2 after the exercise program.

No change in liver lipoprotein levels (VLDL or apoB-100) was found among participants in the physical activity group.

Dr. Klein concludes:

“Our data demonstrate that a moderate intensity exercise program followed by obese patients with NALFD causes a small decrease in IHTG content, even when body weight and total body fat mass are maintained.

Current exercise recommendations seem to have only a modest effect on triglycerides and ALT levels, suggesting that improvement in lipoprotein metabolism and fatty liver (steatosis) may be due to weight loss and not increased physical activity.”

The researchers note that further research is required in order to assess the impact of moderate physical activity on IHTF content in individuals with NAFLD.

Written By Grace Rattue