Socioeconomic Disparities and Other Factors in Dyslipidemia: Insights from NHANES 2017–2020 Data

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper: “Socioeconomic Disparities and other factors in Dyslipidemia: Insights from NHANES 2017–2020 Pre-Pandemic Data“ gives an insight of the socioeconomic influence on dyslipidemia based on the data collected between 2017 and 2020 within NHANES.

It is a well-written manuscript with clear aims and valid conclusions, presenting the strengths and the limitations of this study.

There are some points that require improvement before the paper is considered for publication.

The title should be changes. It is misleading. Why we reffer to the data as pre-pandemic. There is no word about post-pandemic situation, no comparison, thus the current construction gives space for misjudgement.

Are there any findings regarding the socioeconomic situation pre and post-pandemic that can be added into this study to justify the title?

The same comment refers to the term pre-pandemic throughout the text.

What „**” and “*” stand for in Tables 2 and 3? Is it the same as for Table 1. Please add information below the tables.

In the discussion part the prevalence of dyslipidemia is compared with the data from all over the world but predominantly from Africa and Asia. Given that the white population in USA are Europe immigrants or their descendants, are there no data from Europe to compare?  Are there no data from USA from the previous NHANES studies in order to emphasize the current trend? Is there a decrease or increase in the rates of dyslipidemia among the USA population? 

How do you explain no influence of the higher education on the observed results? Yes, there was a higher proportion of those with lower education in the dyslipidemia group, but what about the effects of the higher education on the prevention measures and care for the health and wellbeing? Seems like there are no differences regarding this between those with high school and those with university degrees?

Author Response

The title should be changes. It is misleading. Why we refer to the data as pre-pandemic. There is no word about post-pandemic situation, no comparison, thus the current construction gives space for misjudgement.

• CDC labelled the data as “pre-pandemic” as data were collected up until the pre-pandemic period (March 2020). From their website: “The NHANES program suspended field operations in March 2020 due to the coronavirus disease 2019 (COVID-19) pandemic. As a result, data collection for the NHANES 2019-2020 cycle was not completed and the collected data are not nationally representative. Therefore, data collected from 2019 to March 2020 were combined with data from the NHANES 2017-2018 cycle to form a nationally representative sample of NHANES 2017-March 2020 pre-pandemic data.”

Our study does not explore any association/influence of the pandemic on SES-Dyslipidemia relation. Thank you for your valuable comment, we have removed the term “pre-pandemic” from the title and the rest of the paper.

Are there any findings regarding the socioeconomic situation pre- and post-pandemic that can be added into this study to justify the title?

• Our study does not explore any association/influence of the pandemic on SES-Dyslipidemia relation.

The same comment refers to the term pre-pandemic throughout the text.

• we have removed the term “pre-pandemic” throughout the text.

What “**” and “*” stand for in Tables 2 and 3? Is it the same as for Table 1. Please add information below the tables.

• Added below each of the appropriate tables (*P < 0.05, **P < 0.01, ***P < 0.001). Thank you for noticing this shortcoming.

 

In the discussion part the prevalence of dyslipidemia is compared with the data from all over the world but predominantly from Africa and Asia. Given that the white population in USA are Europe immigrants or their descendants, are there no data from Europe to compare? Are there no data from USA from the previous NHANES studies in order to emphasize the current trend? Is there a decrease or increase in the rates of dyslipidemia among the USA population?

• We have added a comparison with the US population from the previous NHANES study (2003-2006)

              “The prevalence of dyslipidemia in this study was 71.3%, indicating an increase of nearly 18% over the past decade compared to the 53% of U.S. adults with lipid abnormalities estimated by Toth et al. using data from the NHANES 2003–2006.” [22]

How do you explain no influence of higher education on the observed results? Yes, there was a higher proportion of those with lower education in the dyslipidemia group, but what about the effects of the higher education on the prevention measures and care for the health and wellbeing? Seems like there are no differences regarding this between those with high school and those with university degrees.

• We have further clarified the influence of education on risk of dyslipidemia in our discussion section.

“Educational attainment demonstrated a significant association with dyslipidemia in our study. The prevalence of dyslipidemia was notably lower among individuals with a college education or higher (24.24%) compared to those with lower educational attainment, including high school or less (75.76%). Further analysis using weighted multivariable models (Table 5) indicated that individuals with low socioeconomic status (SES) remained at a significantly higher risk of dyslipidemia, even after adjusting for sociodemographic, lifestyle, and medical factors. These findings are consistent with the results of the Prospective Urban Rural Epidemiologic (PURE) study, which reported that lower educational levels were associated with higher cardiovascular risk in high-income countries. “

Reviewer 2 Report

Comments and Suggestions for Authors

This study aimed to analyse the relationship between socioeconomic status and dyslipidaemia using NHANES 2017–2020 data. A cohort of 5,862 adults was examined, focusing on socioeconomic factors (income, education, occupation) and their association with lipid profiles. The authors concluded that low socioeconomic status consistently increased the odds of dyslipidaemia, and while high socioeconomic status demonstrated some protective effects, these were diminished when accounting for lifestyle and clinical factors, highlighting the complex interplay of socioeconomic status and health behaviours.

1. Please, add study design into Abstract section
2. Literature should be up to date, please add newer references

Author Response

1. Please, add study design into Abstract section

• Added in the “Methods” part of the Abstract. Thank you for this suggestion.

2. Literature should be up to date, please add newer references

We have reviewed the literature and added more recent and relevant references to ensure the manuscript reflects the current state of research. Thank you for this suggestion

Reviewer 3 Report

Comments and Suggestions for Authors

This is an important and well-structured study addressing a major public health concern: the association between socioeconomic status (SES) and dyslipidemia. However, some areas need clarification, refinement, and deeper discussion to strengthen the manuscript.

1. Methods: "Based on the model fits, we chose the model with three latent classes...". Authors mention using LCA to classify SES, but without supporting metrics. Please include the model fit indices (e.g., AIC, BIC) for choosing the 3-class solution.
2. The authors excluded participants without complete lipid profiles and SES variables, but it's unclear how missing data for covariates (e.g., smoking, physical activity) were handled. Please state whether participants with missing covariates were excluded, or if imputation methods were applied.
3. Discussion: High SES initially shows a protective effect against dyslipidemia but becomes non-significant after adjusting for lifestyle and medical factors. Authors could discuss more explicitly whether this attenuation suggests mediation (i.e., SES influences lifestyle, which then impacts dyslipidemia) vs. confounding.
4. Discussion: The finding that Non-Hispanic Black individuals had lower odds of dyslipidemia contradicts some prior literature. Authors should consider explaining possible biological or measurement reasons, such as lower triglyceride levels commonly reported in Black populations, or differences in healthcare access.
5. In the subgroup analyses (Table 2 on Pages 7–8 and Table 3 on Page 10), "Middle SES" is used as the reference group but only marked as "Ref" without explanation. Please consistently state that Middle SES is the reference group in both the text and table footnotes to avoid confusion.
6. Tables 2–5 are very detailed but a bit overwhelming. Bold significant p-values and/or ORs for better readability. Consider moving some detailed subgroup tables to Supplementary Material.
7. Limitations: Authors correctly mention the cross-sectional nature and Friedewald equation limitations. However, authors should also mention potential recall bias from self-reported variables (e.g., alcohol consumption, smoking).
8. Please proofread the manuscript to correct any minor grammatical issues.

 

Author Response

1. Methods: "Based on the model fits, we chose the model with three latent classes...". Authors mention using I-CA to classify SES, but without supporting metrics. Please include the model fit indices (e.g., AIC, BIC) for choosing the 3-class solution.

• We’ve added the following in the methods section:

“The model with the 3 latent classes had better fit indices (lower AIC- 34,338.22 and BIC- 34,490.85; lower G2- 16.76) and X²- 16.77), and positive degrees of freedom) than the 2-class (higher AIC- 34,416.74 and BIC- 34,516.29; higher G2 -111.28 and X²- 115.65) and 4-class models (higher AIC, BIC, and negative degrees of freedom). Based on the model fits and model interpretability, we chose the model with three latent classes…”

2. The authors excluded participants without complete lipid profiles and SES variables, but it's unclear how missing data for covariates (e.g., smoking, physical activity) were handled. Please state whether participants with missing covariates were excluded, or if imputation methods were applied.

• Added in the Methods section: “Missing data for covariates were excluded.”

3. Discussion: High SES initially shows a protective effect against dyslipidemia but becomes non-significant after adjusting for lifestyle and medical factors. Authors could discuss more explicitly whether this attenuation suggests mediation (i.e., SES influences lifestyle, which then impacts dyslipidemia) vs. confounding.

• Thank you for your valuable comment. We clarified this further in the discussion section:

“Although higher SES initially exhibited a protective effect against dyslipidemia, this association became non-significant after adjusting for lifestyle behaviors and medical comorbidities. This attenuation supports a mediation model, wherein higher SES promotes healthier behaviors, better access to preventive healthcare, and improved management of chronic conditions, which collectively reduce dyslipidemia risk. Rather than representing simple confounding, our findings suggest that SES influences dyslipidemia indirectly through its impact on modifiable risk factors, highlighting the critical role of health behaviors in mediating socioeconomic disparities in lipid outcomes. This observation is consistent with findings from large prospective cohort studies, which demonstrated that a healthy lifestyle substantially mediates the association between SES and cardiovascular outcomes, including dyslipidemia and mortality.”

 

4. Discussion: The finding that Non-Hispanic Black individuals had lower odds of dyslipidemia contradicts some prior literature. Authors should consider explaining possible biological or measurement reasons, such as lower triglyceride levels commonly reported in Black populations, or differences in healthcare access.

• We’ve addressed this with better explanation in the Discussion section:

“ Racial disparities in dyslipidemia were also evident in this study. Non-Hispanic Whites constituted a significantly larger proportion of individuals with dyslipidemia (40.47%) compared to Non-Hispanic Blacks (23.11%). Moreover, Non-Hispanic Black participants demonstrated lower odds of dyslipidemia, with an adjusted odds ratio (AOR) of 0.513 (p < 0.001). These findings contrast with previous studies, such as the one by An et al., conducted within Kaiser Permanente Southern California, which reported that Non-Hispanic Blacks were at higher risk of developing atherosclerotic cardiovascular disease compared to Non-Hispanic Whites. The observed lower odds of dyslipidemia among Non-Hispanic Black individuals in our study may reflect underlying biological differences, particularly in lipid metabolism. Recent analyses of NHANES data (2007–2018) have shown that Non-Hispanic Black adults generally exhibit lower triglyceride levels compared to other racial groups. Lower triglyceride concentrations among Non-Hispanic Black individuals may partly explain their lower prevalence of dyslipidemia, as hypertriglyceridemia is a key component of dyslipidemia classification. Additionally, disparities in healthcare access, screening practices, and treatment uptake likely influence the diagnosis and management of lipid abnormalities across racial groups. These findings underscore the need for culturally sensitive and equitable cardiovascular prevention strategies.”

 

5. In the subgroup analyses (Table 2 on Pages 7—8 and Table 3 on Page 10), "Middle SES" is used as the reference group but only marked as "Ref" without explanation. Please consistently state that Middle SES is the reference group in both the text and table footnotes to avoid confusion.

• Added as table notes

6. Tables 2—5 are very detailed but a bit overwhelming. Bold significant p-values and/or ORS for better readability. Consider moving some detailed subgroup tables to Supplementary Material.

• We’ve bolded significant p-values and moved Table 3 and 4 to Supplementary Material

7. Limitations: Authors correctly mention the cross-sectional nature and Friedewald equation limitations. However, authors should also mention potential recall bias from self-reported variables (e.g., alcohol consumption, smoking).

• Addressed this in the “Strengths and Limitations” section

8. Please proofread the manuscript to correct any minor grammatical issues.

• Proofread performed. Thank you.

Reviewer 4 Report

Comments and Suggestions for Authors

A study conducted on anonymized data from NHANES to evaluate the association between socioeconomic status (SES) and dyslipidemia. The authors demonstrate that high SES has a protective effect on dyslipidemia, but this is attenuated by the effect of other risk factors, while low SES has an association that persists even considering all confounding factors. The authors explain in detail the method followed, put the results in the correct order and allow the reader to follow their reasoning. Comparison with literature data places the results within the scope of currently available knowledge. Limitations of the study are reported and discussed.

Author Response

Thank you for your comments, we are grateful for your review