Comparison of Risk Factors for NASH and Advanced Fibrosis between Patients with Obese and Non-Obese Nonalcoholic Fatty Liver Disease = Comparison of Risk Factors for NASH and Advanced Fibrosis between Patients with Obese and Non-Obese Nonalcoholic Fatty Liver Disease

다국어 초록 (Multilingual Abstract)

Aims: Non-alcoholic fatty liver disease (NAFLD) has been frequently found in the non-obese as well as in the obese. Furthermore, Asians have a relatively higher prevalence of NAFLD despite lower body mass index (BMI).
We investigated whether pathological features were comparable between obese and non-obese subgroups in a histologically confirmed NAFLD registry cohort.
Methods: We analyzed the cross-sectional cohort derived from the ongoing prospective Boramae NAFLD registry. We graded steatosis, lobular inflammation, and hepatocellular ballooning according to the NAFLD activity score (NAS). Nonalcoholic steatohepatitis (NASH) was diagnosed based on an overall pattern of histological hepatic injury consisting of macrovesicular steatosis, inflammation, or hepatocellular ballooning according to Brunt et al.’s criteria. Additionally, fibrosis was assessed according to a 5-point scale proposed by Brunt and modified by Kleiner et al. Advanced fibrosis was defined as F3.F4.
Results: Among the 365 biopsy-proven NAFLD patients, 87 had non-obese NAFLD and 278 had obese NAFLD in terms of BMI. Patients with obese NAFLD had significantly higher levels of serum alanine aminotransferase (ALT), insulin resistance (HOMA-IR), and adipose tissue insulin resistance than those with non-obese NAFLD. Histological features except steatosis grade were comparable between patients with obese and non-obese NAFLD. Under multivariate logistic regression analyses, serum aspartate aminotransferase (AST), triglycerides, and platelet counts in the non-obese NAFLD subgroup and gender, BMI, serum AST and ALT levels, and HOMA-IR in the obese NAFLD subgroup were independent risk factors for NASH, respectively. Diabetes, serum albumin levels, and HOMA-IR in the non-obese NAFLD subgroup and gender, diabetes, serum AST levels, platelet counts, and HOMA-IR in the obese NAFLD subgroup were significant risk factors for advanced fibrosis, respectively. Moreover, various noninvasive fibrosis tests such as FIB-4, APRI, and adipose tissue IR showed comparable diagnostic performances, irrespective of obesity status.
Conclusions: In terms of the histological characteristics, non-obese NAFLD subtype is not significantly different from obese NAFLD subtype. However, different drivers might account for high-risk progression of non-obese and obese NAFLD.