Nonalcoholic fatty liver disease: The hepatic trigger of the metabolic syndrome

[摘要] Visceral adipose tissue (VAT) is an important risk factor for obesity-related metabolic disorders Therefore a reduction in VAT has become a key goal in obesity management However VAT is correlated with intrahepatic triglycende (IHTG) content so it is possible that IHTG not VAT is a better marker of metabolic diseases We determined the independent association of IHTG and VAT to metabolic functions by evaluating groups of obese subjects who differed in IHTG content (high or normal) but matched on VAT volume or differed in VAT volume (high or low) but matched on IHTG content Stable isotope tracer techniques and the euglycemic-hypennsulinemic clamp procedure were used to assess insulin sensitivity and very-low-density lipoprotein-triglyceride (VLDL-TG) secretion rate Tissue biopsies were obtained to evaluate cellular factors involved in ectopic triglyceride accumulation Hepatic adipose tissue and muscle insulin sensitivities were 41% 13% and 36% lower (p <001) respectively whereas VLDL-triglyceride secretion rate was almost double (p <0 001) in subjects with higher than normal IHTG content matched on VAT No differences in insulin sensitivity or VLDL-TG secretion were observed between subjects with different VAT volumes matched on IHTG content Adipose tissue CD36 expression was lower (p <0 05) whereas skeletal muscle CD36 expression was higher (p <0 05) in subjects with higher than normal IHTG These data demonstrate that IHTG not VAT is a better marker of the metabolic derangements associated with obesity Furthermore alterations in tissue fatty acid transport could be involved in the pathogenesis of ectopic triglycende accumulation by redirecting plasma fatty acid uptake from adipose tissue toward other tissues (C) 2010 European Association for the Study of the Liver Published by Elsevier B V All rights reserved

[发布日期] 2010-12-01

[关键词] NAFLD;Metabolic syndrome;Liver fat;Visceral fat;Insulin resistance