W. Hofmann raises the question of the links between non-alcoholic fatty liver disease (NAFLD) and states of hunger, mentioned in the review as a possible cause of the disease. Here, we would like to point out that in the corresponding table states of hunger are not listed as a cause of NAFLD, but as a cause of secondary hepatic steatosis—this difference is important. Two exemplary conditions are kwashiorkor and marasmus which may be associated with fatty liver, besides muscle wasting. The most likely underlying pathomechanisms are proteolysis of the muscles as well as lipolysis which may lead to fatty liver as the result of an increased production of free fatty acids and a lack of lipoproteins; this was experimentally demonstrated for states of hunger (1). Both M. Hofmeister and H. Walle mention in their letters the “Fatty Liver Index“ (2) which can identify patients with fatty liver with an accuracy of 0.84 based on the parameters body mass index, waist circumference, triglycerides, and gamma-glutamyl transpeptidase. Ultimately, various non-invasive scores are available which can be used to identify high-risk patients. We think that the “NAFLD Fibrosis Score“ mentioned in our article, which was developed by the North American Clinical Research Network (CRN) working group (3), is perfectly suited for this purpose. This score is also based on few routine parameters, viz. age, body mass index, AST (GOT), ALT (GPT), platelet count, and albumin, and can be calculated online; at the same time, the interpretation of the result is provided. This score can rule out advanced fibrosis with a negative predictive value between 0.88 and 0.93 and diagnose advanced fibrosis with a positive predictive value between 0.82 and 0.90; with this, 75% of all liver biopsies could be avoided in the underlying study. The “Fatty Liver Index“ has a negative likelihood ratio of 0.2 for ruling out hepatic steatosis for values <30 and a positive likelihood ratio of 4.3 for values ≥60 (2). However, there is the important difference that the “NAFLD Fibrosis Score“ provides information about advanced fibrosis, while the “Fatty Liver Index“ provides information about hepatic steatosis. A recently published study has demonstrated the superiority of the “NAFLD Fibrosis Score“ over other non-invasive scores, such as the ratio of AST (GOT) and platelet count, the FIB-4 score, or the BARD score (4).
Dr. med. Johannes Weiß
Dr. med. Monika Rau
Prof. Dr. med. Andreas Geier
Universitätsklinik Würzburg, Medizinische Klinik und Poliklinik II,
Schwerpunkt Hepatologie, Würzburg
Conflict of interest statement
Prof. Geier received material resources from Burgerstein Vitamine (study medication SASL34) and from the Velux Foundation (external funds for the SASL34 study).
The remaining authors declare that no conflict of interest exists.
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