Review for 10.1186/1471-230X-11-70 (2011)

Reviewer's report
Title:Discrimination of individuals in a general population at high-risk for
alcoholic and non-alcoholic fatty liver disease based on liver stiffness
Version: 1Date:24 January 2011
Reviewer: Monica Lupsor
Reviewer's report:
Major Compulsory Revisions
1. This study enrolled 423 consecutive Japanese individuals between the ages of
20 and 68 years (Hepatitis B surface antigen negative; Hepatitis C virus antibody
negative).
The authors defined healthy controls based on the following criteria: BMI < 23
kg/m2,
normal LF, findings of fatty liver by ultrasonography absent and daily alcohol
consumption # 20 g/day.
Other possible causes of liver damage should have been excluded, apart from
HVB and HVC. If such other causes existed, they would have influenced the
results.
On the other hand, ultrasonography only identifies steatosis when the liver fat
content in the hepatocyte exceeds 33%. It is therefore possible that some
patients without steatosis on ultrasonography actually had steatosis, even if only
a mild one, and maybe even mild fibrosis.
Please include stricter selection criteria for the “healthy controls” group.
The patients with fatty liver should not be included in this article because:
- there is no histologic confirmation, therefore no rigorous analysis can be
performed
- it was already to be expected that steatosis patients (or having any other liver
condition) have a higher LS than the controls, so the article does not bring any
new information on the subject.
2. The authors state, in the Introduction, that “factors related to LS other than
liver fibrosis have not been clarified”. This statement is not correct. There are
many publications showing the factors influencing liver stiffness, others than
fibrosis: severe inflammation, cholestasis, right ventricular failure. Please take
these into account in the Discussions section.
3. The authors state in the Introduction that “normal reference values for LS in
healthy controls have not been established” - this statement is not correct. There
already are papers establishing “the normal reference values for LS in healthy
controls”. (See the studies by Roulot D et al, J Hepatol. 2008). Please relate to
the already published studies and discuss your results in relation to the data
existing in literature!
Minor Essential Revisions
The authors claim that “Liver stiffness values were significantly higher among
participants with fatty liver than that with NAFLD” (fig 4). This statement does not
correspond to the legend of figure 4 (“Comparison of liver stiffness based on
presence or absence of fatty liver”).
Discretionary Revisions
My opinion is that the article should be modified in order to consider the “healthy
controls” group under stricter conditions. Normal reference values for liver
stiffness and possible factors influencing it in healthy controls only (age, sex,
BMI, metabolic syndrome etc.) should be established.
The patients with fatty liver should not be included because:
- there is no histologic confirmation, therefore no rigorous analysis can be
performed
- it was already to be expected that steatosis patients (or having any other liver
condition) have a higher LS than the controls, so the article does not bring any
new information on the subject.
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests