311-OR: Reduced Hepatic Mitochondrial Metabolism and Markers of Mitochondrial Turnover in Humans Are Linked to NAFLD Progression

Considerable ambiguity exists in the literature regarding the role of hepatic mitochondrial dysfunction in the pathological progression of nonalcoholic fatty liver disease (NAFLD) to steatohepatitis (NASH) and fibrosis. To investigate this relationship, liver biopsies were obtained from patients with morbid obesity undergoing bariatric surgery [n=110, age 44.7±11.7 y, weight 136.3±25.5 kg, BMI 48.7±7.4 kg/m2, AST 35.6±32.1 U/L, ALT 41.0±35.6 U/L, NAFLD activity score 3±2 (NAS; liver injury score: steatosis, ballooning, and inflammation; range: 0-8), fibrosis score 0.5±1.0 (range: 0-4), glucose 104±33 mg/dL] and assessments of mitochondrial function and turnover performed. Data were clustered into four groups based on NAS (No Disease, NAS=0, n=13; Mild NAS=1-2, n=28; Moderate NAS=3-4, n=41; and Severe NAS≥5, n=28). Complete hepatic mitochondrial oxidation of palmitate to CO2 was reduced by ∼50% with Moderate and Severe NAS vs. no disease (p 0.05). In addition to reduced hepatic mitochondrial function, elevated NAS was associated with reduced hepatic mitochondrial biogenesis (PGC1α, SIRT1, PPARα, and AMPKα1 mRNA; p Disclosure M.P. Moore: None. R. Cunningham: None. G.M. Meers: None. S.A. Johnson: None. A.A. Wheeler: None. R. Ganga: None. J. Pitt: None. N. Spencer: None. A.A. Diaz-Arias: None. A. Swi: None. J.A. Ibdah: None. E.J. Parks: None. R.S. Rector: None. Funding National Institutes of Health (R01DK113701); U.S. Department of Veterans Affairs (I01BX003271)