Nonalcoholic fatty liver disease (NAFLD), defined by fatty infiltration of the liver in the absence of excess alcohol consumption, affects an estimated 30% of adults in the United States. A proportion of people with NAFLD will develop progressive, inflammatory nonalcoholic steatohepatitis (NASH), which can progress to liver cirrhosis and liver failure. NAFLD is expected to be the most common indication for liver transplantation by the year 2020. We hypothesize that among adults with NAFLD, aspirin will reduce intrahepatic lipid content, as quantified by 1H magnetic resonance spectroscopy (1H-MRS).

Inclusion Criteria:

• Ages 18 to 70 years
• NAFLD, defined by confirmed hepatic steatosis by imaging or by liver biopsy, in the absence of other causes of hepatic steatosis or significant alcohol consumption. If liver imaging or biopsy has not been performed clinically, liver ultrasound assessment will be performed as part of the screening visit.
• Early-stage liver fibrosis, defined as fibrosis less than or equal to Fibrosis Stage 3 (F3), confirmed by either (1) a recent liver biopsy or (2) a recent elastography / Fibroscan study. If no recent biopsy or elastography/Fibroscan have been performed, a Fibroscan will be performed as part of the screening visit.

Exclusion Criteria:

• Liver fibrosis stage > 3
• Current aspirin use
• Contraindications to aspirin use
• Contraindications to magnetic resonance imaging (MRI)
• Pregnancy or desire to become pregnant
• Breastfeeding

Adverse event data were collected for each trial participant from the date of screening to the final 6-month study visit date.