Many investigations describe the association between obesity and nonalcoholic fatty liver disease (NAFLD) liver function, histopathology, complications, genetic factors and prognosis, but show conflicting and inconclusive results.

A meta-analysis compared the liver function, histopathology, metabolic complications, patatin-like phospholipase domain-containing protein 3 (PNPLA3) genetic polymorphism and prognosis between non-obese and obese NAFLD. 

The relevant studies were extracted from Pubmed, EMBASE, Cochrane databases.

The results of the search and expert commentary were as follows-

• The presence of obesity (according to ethnic-specific BMI cut-off points to define obesity) could predict a worse long-term prognosis in patients with NAFLD. 
• Obesity may not be an independent factor for NASH or advanced fibrosis development in NAFLD patients 
• NAFLD should be treated as the potential population for pharmacologic treatment irrespective of the presence of obesity. 
• PNPLA3 rs738409 may be more related to the progression of non-obese NAFLD than to obese NAFLD. 

The study warranted large-sample, long-term follow-up cohort studies based on liver biopsy since there are limited liver pathology and long-term follow-up data currently.

Source:  Expert Review of Gastroenterology & Hepatology, 2018;12(5):491-502, DOI: 10.1080/17474124.2018.1460202