Prevalence of Nonalcoholic Steatohepatitis in Iran: A Population based Study

Abstract

 

 Background

Non-alcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) is the most common form of chronic liver disease woldwide and is no longer considered a benign disease. Its prevalence has not been deter­mined in a large-scale population-based study in Iran.

Methods

A total of 6583 individuals aged 18 to 65 were randomly selected from three geographically distinct provinces in Iran. Blood samples were obtained from each subject and a questionnaire was completed exploring data including self-admitted regular alcohol use. Serums were tested for anti-HCV antibody (anti-HCV), hepatitis B surface antigen and anti-hepatitis B core antibody. Positive samples for anti-HCV antibody were re-tested and those positive in a repeat ELISA were confirmed by a recombinant immunoblot assay (RIBA) test. Serums were also tested for ALT levels. Subjects with elevated ALT defined as serum ALT ≥40 IU/L with no history of alcohol consumption and negative HBV and HCV infection were considered as “presumed NASHâ€.

Results

In this study 5589 subjects were analyzed. Two hundred and forty two individuals (4.3%) were diagnosed with elevated ALT levels. Among individuals with elevated ALT, 15 (6.2%) were diagnosed with either hepatitis B or hepatitis C. The overall weighted prevalence of pre­sumed NASH was 2.9%. According to multivariate analysis, male sex, urban lifestyle, and being overweight or obese were significantly associated with “presumed NASHâ€.

Conclusion

Obesity and metabolic syndrome, the most predictive factors of fatty liver disease, are increasing in Iran, therefore the prevalence of NAFLD/NASH and related complications are expected to increase in the future. This population based study gives a crude estimate of the prevalence of NASH around the country. Studies with more accurate surrogates of NASH need to be done. The disparity among different provinces merits special consideration.