Review for 10.1186/s12876-019-0972-6 (2019)

Reviewer ’s report  
 
Title:  Prevalence and Long -term Outcomes of Non -alcoholic Fatty Liver Disease Among 
Elderly Individuals from the United States  
 
Version: 0 Date: 08 Mar 2019 
 
Reviewer:  Yao‐Chun  Hsu 
 
Reviewer’s report:  
 
In this study, the authors analyzed a NHANES -III to determine the prevalence of fatty liver (as 
determined by US -FLI score) in US citizens aged 60 years or older, and explored the association 
of fatty liver with incidences of mortality according to age subgroups. They demonstrated a high 
prevalence of  fatty liver in the elderly and found the diagnosis was associated with 
cardiovascular outcomes and mortality in individuals aged between 60~74 years, but not in those 
older than 74 years. Overall, this study is and mainly descriptive and straightforward. It might 
provide useful information to clinicians taking care of patients with fatty liver. Several caveats 
were noted and discussed below.  
 
 
Major comments:  
 
1. The novelty is mediocre as it has been well known that the prevalence of fatty liver 
increases with age and that fatty liver is associated with increased risks of cardiovascular 
outcomes.  
 
2. Using US -FLI score to define fatty liver in the elder may be problematic, given that the 
formula includes age as an explanatory variable. Has US -FLI been independently 
validated in the elderly? Was the diagnostic accuracy (referenced by gold standard such 
as histology or MR spectroscopy) similar across different age s, particularly in those older 
than 70 years? Is there supportive reference?  
 
3. What was analyzed, in fact, was a scoring formula that consisted of age, race -ethnicity, 
waist circumference, gamma -glutamyltransferase, fasting insulin, and glucose. In a sen se, 
the findings regarding the association with metabolic and cardiovascular disorders might 
simply reflect the component variables.  
 
 
Minor points:  
 
1. How many patients were excluded because of insufficient data? The authors did not 
explain why they belie ved "elders (aged 60 and over) who were excluded from the study 
were similar to the final study cohort."  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the  work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
Are you able to assess any statistics in the manuscript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following q uestions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financially from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests  in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
no competing interests  
 
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