Review for 10.1186/s12876-025-03731-3 (2025)

Title: Impact of blood lead and manganese levels on metabolic dysfunction-associated steatotic
liver disease prevalence: insights from NHANES (2017–2020)
Version: 1 Date: 25 Jan 2025
Reviewer:  Amira A A Othman
Reviewer's report:
First of all
I want to congratulate the authors on their work. In this study, Guo et al. aimed to explore the
association between blood lead and manganese levels with Metabolic-Associated Steatohepatitis
(MASLD) using data from NHANES (2017–2020). The result showed elevated blood lead and
manganese levels positively correlated with the Controlled Attenuation Parameter (CAP) and
the prevalence of MASLD. Logistic regression confirmed a higher likelihood of MASLD with
increased blood lead and manganese concentrations. Restricted cubic spline analysis revealed
a nonlinear relationship between manganese levels and MASLD but not with lead. Subgroup
analyses by age, gender, and BMI showed no significant variations.
The authors tried to contribute to this field of research with new findings, nevertheless, there is
an observation for which sufficient justification must be obtained.
In general:
1. The English writing level is shallow, and it is necessary to seek help from an English language
specialist to correct spelling and grammatical errors in the entire text.
2. Abbreviations must be fully written at their first appearance.
3. Use terms like "environmental toxins," "NHANES," and "VCTE" for better indexing.
4. Eliminate repetitive statements.
In Title:
5. The authors may consider indicating the locality at which the National Health and Nutrition
Examination Survey (NHANES) was performed. I suggest “Impact of Blood Lead and
Manganese Levels on MASLD Prevalence: Insights from NHANES (2017–2020)”.
In Abstract section
6. In method: please use “Using data from the National Health and Nutrition Examination
Survey (NHANES) database spanning from 2017 to 2020, a cross-sectional study included X
participants was performed to assess the relationship …….”.
7. It would help if you described the aim of your statistical analysis used throughout the study.
8. Nothing was mentioned about the participant’s age, sex, ethnicity, etc.
9. The type of study: a population-based study.
10. Add quantitative results to highlight key associations
In the Introduction section:
11. Try to provide a summarized description of The National Health and Nutrition Examination
Survey (NHANES) in the background section. You may use the following “NHANES
(www.cdc.gov/nchs/nhanes) is designed to assess the health and nutritional status of adults
and children in the United States. The survey is distinctive in that it incorporates both
physical examinations and interviews. Several cross-sectional, nationally representative health
examination surveys are part of the NHANES program. Questions about demographics,
health insurance status, dietary habits, acute and chronic medical issues, mental health, and
prescription drug use are all included in the health interview. Exam components can change
between survey cycles but typically include blood pressure, dental exams, vision, hearing,
dermatology, fitness, balance and strength testing, respiratory testing, taste and smell, and
body measurements (weight, height, skin folds, body composition scans). Hematology, organ
and endocrine function (e.g., thyroid, kidney), environmental exposure, dietary biomarkers,
metabolic and cardiovascular health, and infectious disease are some laboratory components.”.
12. Simplify and focus on MASLD’s relevance and its link to environmental exposures.
13. Briefly summarize gaps addressed by using NHANES and VCTE.
In the Methods section:
14. Please move the sentences defining the NHANES to the introduction section rather than the
methodology section.
15. Please provide the participants' sociodemographic data.
16. The information on MAFLD is based on the question?
17. What was the source of the covariate data? Explain why VCTE was chosen over other
methods.
18. Justify the thresholds used for step count and intensity categories by referencing prior
literature or explaining their clinical relevance.
19. Add details about sample stratification into quartiles.
20. Expand on the exclusion and inclusion criteria.
In the Results section:
21. In Tables: You can title the statistical test column as “Test of significance” and use U= for
the Mann–Whitney U test, T= for the T-test, and #2 = for the Chi-square test, etc.
22. Include baseline characteristics in a summarized table.
23. Highlight significant p-values and trends.
24. Simplify subgroup analysis findings and their implications.
25. Revise Figure 1 to improve the readability of the participant selection flowchart.
26. dd more intuitive visualizations, like bar graphs for subgroup analyses.
In the Discussion section:
27. The discussion section is one of the final parts of a research paper, in which an author
describes, analyzes, and interprets their findings. They explain the significance of those results
and tie everything back to the research question(s). In this manuscript, there is confusion between
what should be written in the introduction section and the discussion section. Please reconstruct
the discussion section.
28. The bias associated with using a self-reported outcome variable was not mentioned by the
authors.
29. Relate findings more strongly to public health implications and prevention.
30. Add a brief comparison with prior studies using NHANES data. Discuss the novelty of your
study.
31. Include a limitations section discussing NHANES cross-sectional design and potential
confounders.
32. Discuss future studies
33. Discuss the practical implications of your study.
In the conclusion section:
34. The conclusion should restate your main points and provide closure.