Correlation of Vitamin 25(OH)D, Liver Enzymes, Potassium, and Oxidative Stress Markers with Lipid Profile and Atheromatic Index: A Pilot Study
, Konstantina Kazeli 1,2,*, Hristos Ventouris 1, Dionysia Amanatidou 1, Argyrios Gkinoudis 3 and Evgenia Lymperaki 1Round 1
Reviewer 1 Report
The authors try to associate dyslipidemia, which is the main risk factor of CVD, with several biomarkers and oxidative stress.
Line 203 (Charles J Glueck et al.) please note the reference. The same for (Lotfi S. Bin Dahman) .........
Author Response
Original Manuscript ID: JOX-2213474
Original Article Title: “Association between vitamin 25(OH)D, liver enzymes, potassium and oxidative stress markers in dyslipidemia”
To: Journal of Xenobiotics
Re: Response to reviewers
Dear Editor,
Thank you for allowing a resubmission of our manuscript, with an opportunity to address the reviewers’ comments.
We are uploading (a) our response to the comments (below) (response to reviewers) and (b) the final file with the suggested major edits, necessary for the post-acceptance procedure.
Best regards,
Kazeli Konstantina et al.
Reviewer 1
Comments and Suggestions for Authors
The authors try to associate dyslipidemia, which is the main risk factor of CVD, with several biomarkers and oxidative stress.
- Line 203 (Charles J Glueck et al.) please note the reference. The same for (Lotfi S. Bin Dahman)
Answer:
Change has been made.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Thank you for the opportunity to review the manuscript from Ionnidou et al. which demonstrates that there was a negative association of HDL (r=-0.593), 25(OH)D (r=-0.340), K (r=-0.220), 22 SGOT (r=-0.117), and LDH (r=-0.128) and a positive association of LDL (r=0.731), TC (r=0.663), and TG (r=0.584) in with atheromatic index in total studied sample. Despite the quality of this work, I have some important (and other minor) questions, which I would like to describe.
1) The description of the patients involved in this study is not well-defined. Do they take other medications? Most of the time, the hypercholesterolemic patients have polymedication. Please describe more in details these patients..
2) What is the readout of the measurement of ROS, TOS, and TAC in serum?
3) At the end of the introduction, the authors wrote that “The present study aimed to investigate the association between 25(ΟΗ)D, liver enzymes, and oxidative stress parameters in dyslipidemia.” However, the results and the interpretation of the results are quite obscure.
4) The reading of results in tables is quite difficult. I recommend, when it is possible, to make graphs, especially for the correlation between two markers.
5) Line 105, p.3: “….antioxidative status (TAS) is based on the reaction of exogenous superoxide (H2O2) with…”. Please correct, superoxide is not H2O2.
6) In general, the methods have to be described better with more details.
7) This section is the weakest part of the manuscript due to poor writing undermining the discussion of the significance of the results. The outcome is a lack of clarity. Furthermore, the text would be bolstered by more in depth analysis and explanation of the results. What about the mechanisms? Thus, the "Discussion" section needs to be rewritten.
Author Response
Original Manuscript ID: JOX-2213474
Original Article Title: “Association between vitamin 25(OH)D, liver enzymes, potassium and oxidative stress markers in dyslipidemia”
To: Journal of Xenobiotics
Re: Response to reviewers
Dear Editor,
Thank you for allowing a resubmission of our manuscript, with an opportunity to address the reviewers’ comments.
We are uploading (a) our response to the comments (below) (response to reviewers) and (b) the final file with the suggested major edits, necessary for the post-acceptance procedure.
Best regards,
Kazeli Konstantina et al.
Reviewer 2
Comments and Suggestions for Authors
Thank you for the opportunity to review the manuscript from Ionnidou et al. which demonstrates that there was a negative association of HDL (r=-0.593), 25(OH)D (r=-0.340), K (r=-0.220), 22 SGOT (r=-0.117), and LDH (r=-0.128) and a positive association of LDL (r=0.731), TC (r=0.663), and TG (r=0.584) in with atheromatic index in total studied sample. Despite the quality of this work, I have some important (and other minor) questions, which I would like to describe.
- The description of the patients involved in this study is not well-defined. Do they take other medications? Most of the time, the hypercholesterolemic patients have polymedication. Please describe more in details these patients.
Answer:
Additions have been made.
“All participants were healthy, and they were not currently on any medication, sup-plement intake or other drugs. Also, from all participants were collected data about sociodemographic characteristics, such as age and sex.”
- What is the readout of the measurement of ROS, TOS, and TAC in serum?
Answer:
“The levels of reactive oxygen species (ROS) were determined with a fluorometric method using TECAN-infinite200 PRO fluorometer species and performed using the cell-permeable, ROS-sensitive probe 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) fluorescing at 520 nm (λ=480 nm) upon oxidation. The fluorescence intensity is proportional to the ROS levels within the cell cytosol. All measurements of ROS serum levels were estimated in accordance with the linear standard curve of hydrogen peroxide (H2O2) in a concentration range of 0-3 mM. The measurement of total oxidative status (TOS) is based on the reaction of horseradish peroxidase (HRP) with serum oxidants resulting in the conversion of the tetramethylbenzidine (TMB) substrate into a colored blue product and is measured at 450 nm in a spectrophotometer. The quantification is performed by the delivered calibrator, in accordance with the linear standard curve of H2O2 in a concentration range of 0-0.5 mM. The determination of total an-tioxidative status (TAS) is based on the reaction of exogenous H2O2 with serum antioxidants, which consumed some part of the H2O2. The remaining H2O2 is determined photometrically by an enzymatic reaction which converts TMB into a colored product, and is measured at 450 nm in a spectrophotometer. The difference of the sample values “with enzyme” and “without enzyme” is inverse proportional to the antioxidative capacity. The quantification is performed with the enclosed calibrator. All samples were analyzed immediately and measured at least two times.
- At the end of the introduction, the authors wrote that “The present study aimed to investigate the association between 25(ΟΗ)D, liver enzymes, and oxidative stress parameters in dyslipidemia.” However, the results and the interpretation of the results are quite obscure.
Answer:
Changes have been made.
“The present study aimed to investigate the association of 25(ΟΗ)D, K, liver enzymes and oxidative stress parameters with serum lipids levels and atheromatic index. These associations have significant benefits in terms of being considered as potential prognostic markers in early stages of dyslipidemia and could be useful for the management of the possible consequences of dyslipidemia.”
- The reading of results in tables is quite difficult. I recommend, when it is possible, to make graphs, especially for the correlation between two markers.
Answer:
Additions have been made. All tables and graphs have been remade.
- Line 105, p.3: “….antioxidative status (TAS) is based on the reaction of exogenous superoxide (H2O2) with…”. Please correct, superoxide is not H2O2.
Answer:
It has been corrected.
- In general, the methods have to be described better with more details.
Answer:
Changes have been made.
- This section is the weakest part of the manuscript due to poor writing undermining the discussion of the significance of the results. The outcome is a lack of clarity. Furthermore, the text would be bolstered by more in depth analysis and explanation of the results. What about the mechanisms? Thus, the "Discussion" section needs to be rewritten.
Answer:
Changes have been made and the section of Discussion has been rewritten.
Author Response File: Author Response.docx
Reviewer 3 Report
According to Authors the aim of this study was to investigate the association between 25(ΟΗ)D, liver enzymes, and oxidative stress parameters in dyslipidemia. Main my complaint concerns the lack of proper statistical tests to examine the associations. Authors used only correlation and mean comparision, but correlation implies association, but not causation. From this point of view, the manuscript should be rewritten and the data analyzed and presented in a more scientific way. I think that due to the small number of people and diverse age, the results can be treated as a pilot study.
I have also more major comments:
- Title: not closely related to the content of the work
-Abstract: there are lack of Introduction, and the abbreviations used should be described.
-Introduction: it should present the problem addressed in a logical order. The aim should be align with the results.
-Methods: please add inclusion and exclusion criteria and information about drugs; how many biochemical duplications were done; add information about the devices, standards used and references values (specific for age)
- Results: this part requires improvement so that the presented results correspond to the title and the aim of this study; the means are not shown in tables 2 and 3, as titles indicate.
-Discussion: it has to rewrite, indicating your main results at the beginning, but without referring to the numbers. In the following, the results should be explained in a logical order, taking into account the aim of the study. When referring to other authors, we refer only to their names
The manusript requires careful editing.
Author Response
Original Manuscript ID: JOX-2213474
Original Article Title: “Association between vitamin 25(OH)D, liver enzymes, potassium and oxidative stress markers in dyslipidemia”
To: Journal of Xenobiotics
Re: Response to reviewers
Dear Editor,
Thank you for allowing a resubmission of our manuscript, with an opportunity to address the reviewers’ comments.
We are uploading (a) our response to the comments (below) (response to reviewers) and (b) the final file with the suggested major edits, necessary for the post-acceptance procedure.
Best regards,
Kazeli Konstantina et al.
Reviewer 3
Comments and Suggestions for Authors
According to Authors the aim of this study was to investigate the association between 25(ΟΗ)D, liver enzymes, and oxidative stress parameters in dyslipidemia. Main my complaint concerns the lack of proper statistical tests to examine the associations. Authors used only correlation and mean comparision, but correlation implies association, but not causation. From this point of view, the manuscript should be rewritten and the data analyzed and presented in a more scientific way. I think that due to the small number of people and diverse age, the results can be treated as a pilot study.
I have also more major comments:
- Title: not closely related to the content of the work
Answer:
Changes have been made.
“Association of vitamin 25(OH)D, liver enzymes, potassium and oxidative stress markers with lipid profile and atheromatic index. A pilot study.”
- Abstract: there are lack of Introduction, and the abbreviations used should be described.
Answer:
Changes have been made.
“Abstract: According to recent literature, there is a limited amount of data about the association of vitamin 25(OH)D, potassium (K), oxidative stress parameters, and other biomarkers with dyslipidemia, which is an established risk factor for cardiovascular diseases (CVDs). This study aims to investigate the association of lipid profile and atheromatic index TC/HDL, with several bi-omarkers and oxidative stress parameters. A total of 102 volunteers, 67 with atheromatic index TC/HDL> 3.5 (Group A) and 35 with TC/HDL<3.5 (Group B), aged from 26 to 78 years, partic-ipated in this study. Serum levels of triglycerides (TG), total cholesterol (TC), low- and high-density lipoproteins (LDL and HDL), vitamin 25(OH)D [25(OH)D], potassium (K), sodium (Na), lactose dehydrogenase (LDH), liver enzymes including serum glutamic oxaloacetic and glutamic pyruvic transaminases (SGOT and SGPT), gamma-glutamyl transferase (γ-GT), and alkaline phosphatase (ALP) were analyzed using standard photometric methods. Oxidative stress parameters such as reactive oxygen species (ROS) were detected with fluorometric methods, whereas total oxidative (TOS) and antioxidative status (TAS), were measured with spectrophotometric methods. According to the results, a negative association of HDL (r=-0.593), 25(OH)D (r=-0.340) and K (r=-0.220) whereas a positive expected association of LDL (r=0.731), TC (r=0.663), and TG (r=0.584) with atheromatic index in total studied sample were found. In conclusion, patients with a dyslipidemic profile should frequently check not only their lipid profile but also other biomarkers such as 25(OH)D, potassium, and oxidative stress markers to predict dyslipidemia and avoid subsequent disorders.”
- Introduction: it should present the problem addressed in a logical order. The aim should be align with the results.
Answer:
Changes have been made.
- Methods: please add inclusion and exclusion criteria and information about drugs; how many biochemical duplications were done; add information about the devices, standards used and references values (specific for age)
Answer:
Changes have been made.
“In this study, a total of 102 healthy volunteers’ samples were selected (51 males and 51 females) aged 26-78 years, who were examined at the General Hospital of Thessaloniki. The samples were divided into two groups, 67 (35 males and 32 females) with atheromatic index TC/HDL>3.5 (Group A) and 35 participants (16 males and 19 females) with atheromatic index TC/HDL<3.5 (Group B). All samples were collected between 8.00-9.00 a.m. and were centrifuged to collect serum samples as well as plas-ma samples from EDTA-treated blood. Serum and plasma samples were stored at -80oC for 1 month. Hemolyzed samples were excluded. All participants were healthy, and they were not currently on any medication, supplement intake or other drugs. Al-so, from all participants were collected data about sociodemographic characteristics, such as age and sex.”
- Results: this part requires improvement so that the presented results correspond to the title and the aim of this study; the means are not shown in tables 2 and 3, as titles indicate.
Answer:
Changes have been made and all the tables have been remade.
- Discussion: it has to rewrite, indicating your main results at the beginning, but without referring to the numbers. In the following, the results should be explained in a logical order, taking into account the aim of the study. When referring to other authors, we refer only to their names
Answer:
Changes have been made. All the section of Discussion has been rewritten.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
No other comments.
Author Response
We would like to thank you and both the reviewers for their comments and suggestions; we think that their remarks are essential for the improvement of our manuscript. We have carefully considered ALL of the reviewers’ comments and we have revised our manuscript according to them.
We hope that the reviewers will find our responses fully satisfactory and that the revised version of our paper will now be promising for publication in JoX.
Yours sincerely,
Kazeli Konstantina
Author Response File: Author Response.docx
Reviewer 3 Report
I have a few more comments:
- in whole text, the aim, title change "association" on "correlation", because statistical testes used don't indicate "association"
- add an explanation of the abbreviations below the tables
- in Discussion, change the abbreviation to the full name
- in conclusion- you can only show correlation no association
Author Response
We would like to thank you and both the reviewers for their comments and suggestions; we think that their remarks are essential for the improvement of our manuscript. We have carefully considered ALL of the reviewers’ comments (you can see in the following) and we have revised our manuscript according to them.
I have a few more comments:
- in whole text, the aim, title change "association" on "correlation", because statistical testes used don't indicate "association"
Answer: Changes have been made
- add an explanation of the abbreviations below the tables
Answer: Changes have been made
- in Discussion, change the abbreviation to the full name
Answer: Changes have been made
- in conclusion- you can only show correlation no association
Answer: Thank you very much. Changes have been made
We hope that the reviewers will find our responses fully satisfactory and that the revised version of our paper will now be promising for publication in JoX.
Yours sincerely,
Kazeli Konstantina
Author Response File: Author Response.docx
