Research Article Details

Article ID: A02850
PMID: 34219361
Source: Liver Int
Title: PPAR-γ-induced changes in visceral fat and adiponectin levels are associated with improvement of steatohepatitis in patients with NASH.
Abstract: BACKGROUND AND AIMS: Peroxisome proliferator-activated receptor (PPAR)-&#947; agonists decrease hepatic/visceral fat (VF) and improve necroinflammation despite subcutaneous (SC) fat weight-gain. Understanding the impact of changes in VF, VF-to-SC fat distribution (VF/SC) and adiponectin (ADPN) levels in relation to histological improvement after weight-loss or pioglitazone is relevant as novel PPAR-&#947; agonists are being developed for treating non-alcoholic steatohepatitis (NASH). METHODS: Fifty-five patients with NASH received a -500&#160;kcal/d hypocaloric diet and were randomized (double-blind) to pioglitazone (45&#160;mg/d) or placebo for 6-months. Before and after treatment patients underwent a liver biopsy and measurement of hepatic/peripheral glucose fluxes, hepatic/adipose tissue-IR and, in 35 patients, hepatic and VF/SC-fat was measured by magnetic resonance spectroscopy/imaging. Data were examined by multivariable statistical analyses combined with machine-learning techniques (partial least square discriminant analysis [PLS-DA]). RESULTS: Both pioglitazone (despite weight-gain) and placebo (if weight-loss) reduced steatosis but only pioglitazone ameliorated necroinflammation. Using machine-learning PLS-DA showed that the treatment differences induced by a PPAR-&#947; agonist vs placebo on metabolic variables and liver histology could be best explained by the increase in ADPN and a decrease in VF/SC, and to a lesser degree, improvement in oral glucose tolerance test-glucose concentrations and ALT. Decrease in steatosis and disease activity score (ballooning plus lobular inflammation) kept a close relationship with an increase in ADPN (r&#160;=&#160;-.71 and r&#160;=&#160;-.44, P&#160;<&#160;.007, respectively) and reduction in VF/SC fat (r&#160;=&#160;.41 and r&#160;=&#160;.37, P&#160;<&#160;.03 respectively). CONCLUSIONS: Reduction in VF and improved VF/SC-distribution, combined with an increase in ADPN, mediate the histological benefits of PPAR-&#947; action, highlighting the central role of fat metabolism and its distribution on steatohepatitis disease activity in patients with NASH.
DOI: 10.1111/liv.15005