Biomarkers in nonalcoholic fatty liver disease-the emperor has no clothes?

Fatty liver is present in over ten percentage of the world population and it is a growing public health problem. Nonalcoholic fatty liver disease (NAFLD) is not a single disease, but encompasses a spectrum of diseases of different etiologies. It is difficult to find highly specific and sensitive diagnostic biomarkers when a disease is very complex. Therefore, we should aim to find relevant prognostic markers rather than accurate diagnostic markers which will help to minimize the frequency of liver biopsies to evaluate disease progression. There are several biomarker panels commercially available, however, there is no clear evidence that more sophisticated panels are better compared to simple criteria such as, presence of diabetes over five years, metabolic syndrome, obesity, obstructive sleep apnea, aspartate transaminase/alanine transaminase (ALT) ratio > 0.8 or ferritin levels > 1.5 times normal in patients with over six month history of raised ALT and/or ultrasonological evidence of fat in the liver. Currently the biomarker panels are not a replacement for a liver biopsy. However the need and benefit of liver biopsy in NAFLD is questionable because there is no convincing evidence that biopsy and detailed staging of NAFLD improves the management of NAFLD and benefits the patient. After all there is no evidence based treatment for NAFLD other than management of lifestyle and components of "metabolic syndrome".