Prevalence of non alcoholic fatty liver disease and associated factors?

In regard to the article by Denova et al. [1], it should be highlighted that, based on the liver function tests together with other biochemical tests and anthropometric values, several indices are generated and are used for the non-invasive diagnosis of non-alcoholic fatty liver disease (NAFLD) [2]. However, it should be mandatory in every study to exclude subjects with an excessive alcohol consumption and previous liver diseases such as chronic infection with hepatitis B or C viruses [3–5]. Therefore, attention is called to the fact that in this study, Denova et al. refer that “the prevalence of NAFLD was 53.2%”, but at the same time 54% of the participants included in the analysis consumed alcohol and, furthermore, other frequent causes of hepatic function test alterations were not excluded. The lack of consistency of factors such as the low socioeconomic status found in the study by Denova et al. compared to those studies performed worldwide may be also related to a sample selection bias for the diagnosis of NAFLD. Therefore the authors should adjust their results and conclusion accordingly to the aforementioned considerations.