The pathological role of visceral fat accumulation in steatosis, inflammation, and progression of nonalcoholic fatty liver disease

Abstract

Background Our previous studies have indicated a close association between visceral fat accumulation and hepatic steatosis in nonalcoholic fatty liver disease (NAFLD). This study investigated whether visceral fat accumulation was related to the pathogenesis and disease progression of nonalcoholic steatohepatitis (NASH)/NAFLD. Methods First, a total of 550 subjects who underwent a health checkup and measurement of visceral fat accumulation, done with a bioelectrical impedance analyzer (X-SCAN; Owa Medical, Fukuoka, Japan), were included. The relationship between visceral fat accumulation and biochemical parameters was examined. Second, a total of 74 patients with NASH/NAFLD who underwent liver biopsy were reviewed. Visceral fat accumulation was determined by abdominal computed tomography. The association between visceral fat accumulation and the histopathological grade/stage determined by the NAFLD activity score and Brunt's classification was evaluated. Results There was a significant relationship between visceral fat accumulation and glucose, triglyceride, and alanine aminotransferase (ALT; r = 0.423, P \ 0.01). In stepwise regression analysis, visceral fat area (VFA), serum triglyceride level, and serum low-density lipoprotein (LDL)-cholesterol level were selected as predictor variables for serum ALT level, in a continuous manner (serum ALT level = -1.359 ? 0.143 9 VFA ? 0.046 9 triglyceride ? 0.059 9 LDL, R 2 = 0.217, P \ 0.001). In patients with NASH, there was no correlation between histological grade and the visceral fat volume. Visceral fat accumulation in patients with stage 3/4 advanced NASH was greater than that in patients with stage 1/2 early NASH (P \ 0.05). Conclusions These results suggest that visceral fat accumulation plays a role in steatosis and fibrosis in the pathogenesis and prognosis of NAFLD.

Hepatic FDG Uptake is not Associated with Hepatic Steatosis but with Visceral Fat Volume in Cancer Screening

“…Previous study has also reported BMI was the strongest determinant of liver FDG uptake [13]. They recommended screening for the metabolic syndrome in the subject with high FDG uptake of the liver [11].…”

“…We drew ROI of visceral fat area to measure the volume of each subject directly. Visceral fat accumulation has been known to play a role in steatosis and fibrosis in the pathogenesis and prognosis of nonalcoholic fatty liver disease [13]. Visceral obesity induces a chronic low-grade inflammatory state, because chemokines released by hypertrophied adipocytes induce macrophage accumulation in visceral fat tissue [14].…”

Circulating phospholipid profiling identifies portal contribution to NASH signature in obesity

“…Extent of hepatic inflammation and fibrosis also associated with visceral fat independent of insulin resistance and hepatic steatosis [13][14] [15]. These findings indicate potential contribution of visceral fat to worsening liver condition through release of bioactive molecules such as cytokines into hepatic portal system draining into liver, thus supporting the portal hypothesis.…”

The Symptoms of Gastroesophageal Reflux Disease Correlate with High Body Mass Index, the Aspartate Aminotransferase/Alanine Aminotransferase Ratio and Insulin Resistance in Japanese Patients with Non-alcoholic Fatty Liver Disease

“…Our previous studies demonstrated that visceral fat accumulation, not obesity as indicated using the high body mass index (BMI), was a main risk factor for NAFLD in Japanese individuals and that these subjects could recover from NAFLD by the reduction of fat accumulation (12)(13)(14)(15). These findings suggested that NAFLD may be related to GERD symptoms.…”