Overview
There is no known cure or regulatory agency approved drug therapy for nonalcoholic fatty liver disease (NAFLD), the leading cause of liver disease worldwide, and its progressive type, NASH. This places increased importance on using exercise to treat NAFLD.
While physical activity is recommended for all with NAFLD, how to best prescribe exercise as a specific treatment remains unknown, including what dose of exercise is most effective.
Description
The mechanism explaining how exercise training benefits patients with NAFLD and NASH is unclear. The AMPK pathway may be responsible for the benefits seen with exercise training because: 1) AMPK has a liver-specific role in hepatic de novo lipogenesis and fatty acid oxidation, 2) AMPK activity is abnormally low in NAFLD and 3) NAFLD animal models demonstrate exercise changes the liver-specific AMPK pathway, leading to less liver fat accumulation by reducing lipogenesis and increasing fatty acid oxidation (This has not been studied in patients). Importantly, exercise-induced AMPK activation appears to be dose dependent.
Eligibility
Inclusion Criteria:
- Age 18-69 years
- Sedentary [<90 min/wk of exercise identified by the Get Active Questionnaire (GAQ)
- BMI >25kg/m2
- Liver biopsy within six months prior to enrollment showing:
- NASH defined by NASH Clinical Research Network (CRN) histology scoring system (NAS) >4 and MRI-PDFF >5% and;
- Liver fibrosis stage 1-3
Exclusion Criteria:
- Active cardiac symptoms
- Body mass index (BMI) >45kg/m2
- Cancer that is active
- Inability to walk >2 blocks
- Institutionalized/prisoner
- Other liver disease
- Pregnancy
- Secondary hepatic steatosis
- Severe comorbidities
- AUDIT-C questionnaire identified significant alcohol use
- Substance abuse/active smoking
- Uncontrolled diabetes (changes in drug dosing over previous three months or A1c >9%)
- GAQ response indicates exercise may be unsafe.