Association Between Quantity of Liver Fat and Cardiovascular Risk in Patients With Nonalcoholic Fatty Liver Disease Independent of Nonalcoholic Steatohepatitis

Background & aims: The association between quantity of liver fat and the presence of metabolic syndrome needs to be assessed systematically. We aimed to determine the association between the quantity of liver fat and the presence of the metabolic syndrome in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD), independent of nonalcoholic steatohepatitis (NASH).

Methods: We recruited 146 patients with well-characterized biopsy-proven NAFLD and 50 individuals without NAFLD (controls) to participate in a case-control study at the NAFLD Translational Research Unit at the University of California San Diego. Liver fat was quantified in patients with NAFLD and controls using an advanced magnetic resonance imaging-based biomarker, the proton-density-fat-fraction (MRI-PDFF). Patients with NAFLD were divided into groups based on whether they were above or below the median MRI-PDFF value (15.4% in patients with NAFLD); the MRI-PDFF value for controls was less than 5%. The primary outcome was the presence of the metabolic syndrome using Adult Treatment Panel III criteria without and with adjustment for the presence of NASH.

Results: Compared with NAFLD patients with MRI-PDFF values below the median, and compared with controls, NAFLD patients with MRI-PDFF values above the median were more likely to have abdominal obesity (P < .0001), lower levels of high-density cholesterol (P < .0001), higher levels of triglycerides (P < .0001), and higher fasting glucose levels (P < .001). Compared with NAFLD patients with MRI-PDFF values below the median, NAFLD patients with MRI-PDFF above the median were more likely to have the metabolic syndrome (60.3% vs. 44.4%; P < .04), independent of biopsy-detected NASH.

Conclusions: Increased liver fat content in patients with NAFLD is associated with increased rates of the metabolic syndrome, independent of NASH. There appears to be an association between the quantity of liver fat and the risk for cardiovascular disease in patients with NAFLD.