Review for 10.1186/s12876-024-03410-9 (2024)

Title: Association between lipid accumulation products and gallstones: an analysis of the
National Health and Nutrition Examination Survey 2017-2020
Version: 0 Date: 18 Aug 2024
Reviewer:  Amira A A Othman
Reviewer's report:
First of all
I want to congratulate the authors on their work. In this study, Wang et al used data from the
2017–2020 National Health and Nutrition Examination Survey (NHANES) for Americans, this
research aims to investigate the potential association between Lipid Accumulation Products
(LAP) and the risk of gallstones in adult US citizens. Lipid accumulation product (LAP) is
an index calculated by waist circumference (WC) and triglyceride (TG), which reflects lipid
toxicity.
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 Title:
1. The authors may consider indicating the use of National Health and Nutrition Examination
Survey (NHANES) data in the title.
I suggest “Association between lipid accumulation products and gallstones: an analysis of the
National Health and Nutrition Examination Survey 2017-2020
In Abstract section
2. What is the type of such an observational study? Is it a cross-sectional study?
3. It would help if you described the aim of your statistical analysis. For example, Multivariate
linear regression models were used to examine the linear connection between WWI and
gallstones incidence. Fitted smoothing curves and threshold effect analysis were used to describe
the nonlinear relationship.
4. A two-part linear regression model was also used to estimate threshold effects.
5. Nothing was mentioned about the participant’s age.
6. The abbreviation such as NHANES, etc. in the abstract and throughout the manuscript should
be fully written when mentioned for the first time.
7. [2.28 (1.66, 3.13)] better expressed as (OR = 2.28, 95% CI: 1.66#.13).
In the Background section:
8. 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 a few
examples of laboratory components.”.
9. Authors must give an account of Gallstones, one of the most prevalent digestive system
disorders in the world, the symptoms if present, the risk factors, the affection % in the American
population, etc.
(https://doi.org/10.3389/fnut.2024.1428488 ,
In the Methods section:
10. Based on the gallstone status reported in the questionnaire (MCQ550 - Has your doctor ever
told you you have gallstones?), the existence of gallstones was evaluated. What If the participant
had not previously consulted a physician or health professional?
That sentence may require some modification for clarity and spelling revision. It may be
“The outcome variable was the occurrence of gallstone. To assess gallbladder stones,
questionnaires were used, including: “Has a doctor or other health professional ever
told you that you had gallstone?”
11. The information on gallstones is based on the question "Have you ever had a gallstone? ". It
does not give any information on the type of Gallstones. Depending on the etiology, gallstones
have different compositions. The three most common types are cholesterol gallstones, black
pigment gallstones, and brown pigment gallstones.
12. Lipids include LDL cholesterol, high-density lipoprotein (HDL) cholesterol, and
triglycerides. Dyslipidemia results in abnormal levels of lipids (fats) in the blood. Why did the
study focus on TG only?
13. What was the source of the covariate data?
14. Covariates: How did the authors confirm the diagnosis of cancers, asthma, hypertension,
diabetes, etc.? Was it from questionnaires?
15. Statistical analysis: please re-write.  You may find the following text useful:
EmpowerStats 4.0 (http://www.empowerstats.com/) is being used. While categorical data are
expressed as proportions, continuous variables are summarized as mean ± SD. To investigate
the relationship between gallstones and LAP, multivariate logistic regression models were
employed. Three models were used to construct the multivariate test: Model 2 included
adjustments for gender, age, race, marital status, PIR, and education level; Model 3 included
adjustments for all covariates. Model 1 did not include any adjustments. The variables were
changed to perform fitted smoothing curves. To examine the stability of the connection
across subgroups of age, gender, hypertension, diabetes, and other conditions, multiple logistic
regression models were employed.
In the Results section:
16. Baseline characteristics should be Baseline characteristics of participants
17. Pointing out that the results are in table number such and such... was not done correctly
(Table 1, 2, etc.).
18. Model 3 was dubbed a "fully corrected model" by the authors. Seldom is this employed in
scholarly settings.
19. In Table 2, Tertiles 1, 2, and 3 are presented, but the readers will not know the cuff-off for
these tertiles.
20. Subgroup analyses must be performed to evaluate the effect of LAP on gallstones and their
stability in different populations.
21. Future article readers may not know whether the above-mentioned variables were originally
collected as continuous data during data collection by NHANES, or whether the data were
originally categorized in the current study. In addition, in case there is a methodology article
published by NHANES or by other authors that specifically describes the variables, the authors
of the current study may consider citing that paper in the methodology section where the authors
of the current study mentioned the NHANES website.
22. The marital status category should be categorized into cohabitation (married/living with a
partner) and solitude (widowed/divorced/separated/unmarried).”
In the Discussion section:
23. I would suggest a language check throughout the entire manuscript. There are typos and
minor grammar mistakes.
24. The bias associated with using a self-reported outcome variable was not mentioned by the
authors. Since the majority of gallstones are clinically silent, it is possible to incorrectly diagnose
someone as having or not having gallstones. Results could get skewed as a result.
25. Add Limitations.