Stenosis of Carotid Arteries and Concentration of Some Blood Lipid Parameters amongst Tobacco Smokers in Abha: A Case–Control Study

Round 1

Reviewer 1 Report

This is a nice study, the main problem is a very small number of included participants, which make much harder for the conclusions to be make. In addition, it is not very clear if the main groups are similar enough to enable further comparisons.

First question is, could you determine the statistical power of the study? If it is too low, you are not able to statistically prove even an existing phenomena due to low number of participants, which are further sub-grouped. In case you do not have sufficient power, more participants would need to be included.

Secondly, please present a clear baseline comparison of the two main groups included (smoker/non-smokers). Are there any statistical baseline differences in any of the relevant factors to influence IMT (sex, age, BMI, height, RR, ...). For drawing any final conclusions, this aspect must be very clear.

 

 

 

 

 

 

 

Author Response

1. This is a nice study, the main problem is a very small number of included participants, which make much harder for the conclusions to be make. In addition, it is not very clear if the main groups are similar enough to enable further comparisons.

Reply: Thank you very much for the nice comment. We have added a paragraph about the research design of this study, which is descriptive, cross-sectional and case- control study. Such studies have weakness and advantages. One of the weaknesses is the difficulty to draw causal or relational effects. Also, we cited a new reference [10].

Also, we gave the study design a separate subheading to tackle the valuable comments you raised.

 

 

2. First question is, could you determine the statistical power of the study? If it is too low, you are not able to statistically prove even an existing phenomena due to low number of participants, which are further sub-grouped. In case you do not have sufficient power, more participants would need to be included.

Reply: As this is case control and not a survey study, the statistical tests which are used in these studies are to compare the mean values of the studied parameters using the t-test and ANOVA test. However, if you suggest any other statistical analysis, we are ready.

 

3. Secondly, please present a clear baseline comparison of the two main groups included (smoker/non-smokers). Are there any statistical baseline differences in any of the relevant factors to influence IMT (sex, age, BMI, height, RR, ...). For drawing any final conclusions, this aspect must be very clear.

Reply: The smokers and non-smokers were matched with regard to the age and BMI, while all the study subjects were males. This statement is added in the description of the study subjects. Also, two lines were added to respond to your valuable comment [“The research’s subjects were divided into two major groups: smokers and non-smokers. Each of the smoker and non-smoker groups were divided into” – lines 60,61]. All lines in red were added afterwards to improve the quality of the research.

Author Response File: Author Response.docx

Reviewer 2 Report

The paper entitled Stenosis of Carotid Arteries and Concentration of Some Blood Lipid Parameters amongst Tobacco Smokers in Abha: A Case
Control Study points out the negative effect of smoking on CVD and the change in lipid profile. 

In the abstract, the authors mention the term "Abha cardiovascular abnormalities", which is not explained in the introduction and probably stems from an incorrect translation of the original manuscript. I do not feel qualified to evaluate the language level of the manuscript, but I believe that several inconsistencies come from incorrect translation.

In the Materials and Methods section, it is stated, that the respondents of the study did not suffer from any diseases, but among them were also people with confirmed obesity. Nowhere in the text or in the tables is it possible to trace the data on the proportion of these people. It is also not stated the number of people after classification into groups according to age.

I also have reservations about the above division of probands into three groups based on BMI and age, as the main division of probands was based on smoking and is not mentioned in the Study design, community and sampling procedure (lines 60-62). 

The description of the procedure of the blood lipid parameters analysis is not clear (lines 71-73). In the Statistical analysis section, the t-test is not specified. 

The description of the results given in the tables is not unambiguous, I recommend describing the results separately with regard to the length of smoking (up to 5 - I assume years - and separately over 6 - again just an assumption - years). As neither the length of smoking nor the frequency is not stated in which units it was recorded. Table 5 is completely missing the header as in the other tables, the number of probands in individual groups. 

Because you know, how many of the 19 smokers were obese or normal weight, how would you explain, which has a greater effect on lipid parameters, BMI or smoking. 

Due to the small number of respondents and inconsistent results, your conclusions are very bold. I definitely do not agree with the conclusion that IMT represents a lipid profile, although it is closely related to. 

I recommend examining the results in more depth and drawing more precise conclusions. 

 

line 22: spectrophotometer meter

line 27 and throughout the text: strokes

line 35: of the incidences of strokes. 25...

line 42: ...main risk factor for CVD.... lifestyle - should be unhealthy lifestyle

line 63: random blood was taken 

line 78: performance ... were done

line 80: after due magnification ?

line 84: the due effects

line 239: ages and BMIs 

Author Response

To                                                                                            Date: 05.02.2021

The Editor,

Ref: MANUSCRIPT ID: applsci-1107807

Title: Original article entitled “Stenosis of Carotid Arteries and Concentration of Some Blood Lipid Parameters amongst Tobacco Smokers in Abha: A Case Control Study”.

 

Dear Sir,

       I wish to thank you for taking the trouble of going through the processes for kind consideration of publication of my article. As per the Editorial review and Reviewer’s comment’s, the above cited article has been revised/corrected and resubmitted to you for kind consideration for publication in applied Sciences. The corrections /modifications are given below:

 

 

 

 

(x) I would not like to sign my review report
( ) I would like to sign my review report

English language and style

( ) Extensive editing of English language and style required
( ) Moderate English changes required
( ) English language and style are fine/minor spell check required
(x) I don't feel qualified to judge about the English language and style

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	( )	( )	(x)	( )
Is the research design appropriate?	( )	(x)	( )	( )
Are the methods adequately described?	( )	( )	(x)	( )
Are the results clearly presented?	( )	( )	(x)	( )
Are the conclusions supported by the results?	( )	( )	(x)	( )

 

Replies to the Reviewer 1

 

(Comments and Suggestions for Authors)

 

1. The paper entitled Stenosis of Carotid Arteries and Concentration of Some Blood Lipid Parameters amongst Tobacco Smokers in Abha: A Case Control Study points out the negative effect of smoking on CVD and the change in lipid profile.  In the abstract, the authors mention the term "Abha cardiovascular abnormalities", which is not explained in the introduction and probably stems from an incorrect translation of the original manuscript. I do not feel qualified to evaluate the language level of the manuscript, but I believe that several inconsistencies come from incorrect translation.

Reply: Thank you very much for your advice. Abha is deleted from the abstract

2. In the Materials and Methods section, it is stated, that the respondents of the study did not suffer from any diseases, but among them were also people with confirmed obesity. Nowhere in the text or in the tables is it possible to trace the data on the proportion of these people. It is also not stated the number of people after classification into groups according to age.

Reply: Yes, some of them are obese, but they were healthy and not suffering from any disease symptoms. With regards to the small number of subgroups, we have mentioned this issue as a limitation of this study in the discussion section. Lines have been added stating the number of people after classification into groups according to age.

3. I also have reservations about the above division of probands into three groups based on BMI and age, as the main division of probands was based on smoking and is not mentioned in the Study design, community and sampling procedure (lines 60-62). 

Reply: Two lines are added to respond to your valuable comment [“The research’s subjects were divided into two major groups: smokers and non-smokers. Each of the smoker and non-smoker groups were divided into” – lines 60,61].

4. The description of the procedure of the blood lipid parameters analysis is not clear (lines 71-73). In the Statistical analysis section, the t-test is not specified. 

Reply: We did not describe in detail the procedure of the lipid profile measurement, because it is a routine work, and nothing is new regarding the technique and the procedure.

We have used the independent- samples t- test and it is added to the manuscript (line -85).

5. The description of the results given in the tables is not unambiguous, I recommend describing the results separately with regard to the length of smoking (up to 5 - I assume years - and separately over 6 - again just an assumption - years). As neither the length of smoking nor the frequency is not stated in which units it was recorded. Table 5 is completely missing the header as in the other tables, the number of probands in individual groups. 

Reply: The table is changed by adding the duration and frequency units and by adding the numbers of each subgroup.

Table 5 is changed by adding a head row and the number study subjects in each subgroup.

 

 

 

6. Because you know, how many of the 19 smokers were obese or normal weight, how would you explain, which has a greater effect on lipid parameters, BMI or smoking. 

Reply: The smoking effect on carotid arteries thickness is higher than the effect of BMI. A paragraph is added at the end of the BMI effect on the lipid profile and carotid arteries thickness.

 

7. Due to the small number of respondents and inconsistent results, your conclusions are very bold. I definitely do not agree with the conclusion that IMT represents a lipid profile, although it is closely related to. I recommend examining the results in more depth and drawing more precise conclusions.

Reply: As per your advice, the fifth conclusion is deleted.

 

line 22: spectrophotometer meter   corrected

line 27 and throughout the text: strokes   corrected

line 35: of the incidences of strokes. 25...      corrected

line 42: ...main risk factor for CVD.... lifestyle - should be unhealthy lifestyle   corrected

line 63: random blood was taken.       The statement is rephrased

line 78: performance ... were done – Removed for better understanding

line 80: after due magnification ? - Removed for better understanding

line 84: the due effects – “due” removed

line 239: ages and BMIs - Rephrased

 

Author Response File: Author Response.docx

Reviewer 3 Report

Regarding methods, the use of non-fasting blood samples is adequate, but the participants should be counsel to avoid an extremely high-fat or fast-food meal in the preceding 12 h. In the case of high TG levels (400 mg/dl), the sample should be tested again collected in the fasting state. Some of the participants must have high TG levels, according to some group results (319.9 ± 329.2 mg/dl). These aspects are not described.

The results are not clearly presented. The parameters duration and frequency of smoking are not well defined (years, cigarettes?).

The results should clear present the number of participants (n) by group, namely in table 2 and table 3. I’ am afraid that the number of participants in each group becomes too small to get significant information from them.

In respect to the results presented in table 5, I do not agree that is carotid artery IMT that play some role in lipid profile, but the opposite. The same idea was present in the discussion (line 177).

The conclusions are very limited by the small number of participants and some of them could not be taken.

Author Response

To                                                                                   Date: 05.02.2021

The Editor,

Ref: MANUSCRIPT ID: applsci-1107807

Title: Original article entitled “Stenosis of Carotid Arteries and Concentration of Some Blood Lipid Parameters amongst Tobacco Smokers in Abha: A Case Control Study”.

 

Dear Sir,

       I wish to thank you for taking the trouble of going through the processes for kind consideration of publication of my article. As per the Editorial review and Reviewer’s comment’s, the above cited article has been revised/corrected and resubmitted to you for kind consideration for publication in Applied Sciences. The corrections /modifications are given below:

 

 

 

 

Open Review

(x) I would not like to sign my review report
( ) I would like to sign my review report

English language and style

( ) Extensive editing of English language and style required
( ) Moderate English changes required
( ) English language and style are fine/minor spell check required
(x) I don't feel qualified to judge about the English language and style

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	(x)	( )	( )	( )
Is the research design appropriate?	( )	(x)	( )	( )
Are the methods adequately described?	(x)	( )	( )	( )
Are the results clearly presented?	( )	( )	(x)	( )
Are the conclusions supported by the results?	( )	( )	(x)	( )

 

 

 

 

 

 

 

 

Replies to Reviewer – 2 (According to Comments and Suggestions for Authors)

1. Regarding methods, the use of non-fasting blood samples is adequate, but the participants should be counsel to avoid an extremely high-fat or fast-food meal in the preceding 12 h. In the case of high TG levels (400 mg/dl), the sample should be tested again collected in the fasting state. Some of the participants must have high TG levels, according to some group results (319.9 ± 329.2 mg/dl). These aspects are not described.

Reply: Thank you very much for your advice.

The participants with triglycerides ≥ 400 are 5 participants, I personally contacted them and asked them your question – “Did you eat a high fat meal in the preceding 12 hrs.?”, all of them answered no. The following sentence has been added in the Materials and Methods section – “The participants were counselled to avoid an extremely high-fat or fast-food meal in the preceding 12 hrs. of taking blood” – lines 65, 66.  My second question was – “Please confirm that you do not suffer from any disease”, and they confirmed. However, we referred them to the research group physician (Dr Safar Alshahrani), but unfortunately, we are not able to follow them due to COVID-19 and some other circumstances.

Non-smokers

Triglycerides         Age           BMI         

530                           35            32.4

400                           42            24.7

1118                         25            37

Smokers

Triglycerides       age         BMI          smoking frequency (cigarette)           duration (years) 

836                         45          34.2                         15                                                     15

486                         26           24.2                         3                                                       10

For that reason, we did not mention their issue in the manuscript. According to our criteria, we can involve them in our study, since they did not eat an extremely high-fat or fast-food meal (in the preceding 12 hrs.) or suffer from any disease symptoms.

2. The results are not clearly presented. The parameters duration and frequency of smoking are not well defined (years, cigarettes?).

Reply: The units of duration and frequency were added in the tables

3. The results should clear present the number of participants (n) by group, namely in table 2 and table 3. I’ am afraid that the number of participants in each group becomes too small to get significant information from them.

Reply: The number of the participants in all the subgroups is added. We agree that the number of the participants in the subgroups is small, so the study limitations are present in the discussion section before the conclusions.

4. In respect to the results presented in table 5, I do not agree that is carotid artery IMT that play some role in lipid profile, but the opposite. The same idea was present in the discussion (line 177).

Reply: As per your advice, the statement is changed to: “From the above-mentioned results, it is apparent that carotid artery IMTs is associated with abnormal lipid profile”.

5. The conclusions are very limited by the small number of participants and some of them could not be taken.

Reply: We agree to your comment, simply because this is a descriptive study and one of the major negative points of the descriptive studies is that we cannot generalize their results. But still descriptive studies are useful in highlighting problems for future studies.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Thanks for clarifications.

• I would suggest that at the first part of Results a table or description is added comparing directly only the main demographic and CVD risk factors of the main two groups
• I would suggest that a statistician confirms the statistical validity of conclusions
• I would suggest adding LDL-C or at least non-HDL-C, which are the standard lipid measures.

Author Response

1. I would suggest that at the first part of Results a table or description is added comparing directly only the main demographic and CVD risk factors of the main two groups.

Reply: A new table is added. Thank you very much for this nice improvement of the manuscript. Really, we did not evaluate the effect of the CVD risk factors on the two study groups when we did this research. Fortunately, the effect of the CVD risk factors on the two study groups was insignificantly different.  Many thanks.

 

2. I would suggest that a statistician confirms the statistical validity of conclusions.

Reply: The final author of the manuscript; Mohammed Elimam Ahamed Mohammed is a biochemist and is well trained in using the SPSS program and the essentials of biostatistics.

 

3. I would suggest adding LDL-C or at least non-HDL-C, which are the standard lipid measures.

Reply: We have the LDL concentration using the Friedewald equation, but the problem is that the number of samples will be minimized due to the high TG concentration (≥400 mg/dl) as follows:

Non-smokers (4) the total will be (31), while the smokers will miss (2) and the total will be (17). Also, some studies doubt about the calculated and measured LDL are they insignificantly different?

However, the calculated LDL for the non-smokers and smokers were (72.5± 28.8) and (65± 21.8), respectively. They were insignificantly different (p- value= 0.48).

If we added the LDL, It would create another drawback for the study because we did not measure the LDL, but calculated it.

If you insist to include, we are ready to do so.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear authors, 

Due to the small number of respondents, the statistical analysis is weak, but thanks to additional information, it gained informative value. 

Author Response

Dear authors, 

Due to the small number of respondents, the statistical analysis is weak, but thanks to additional information, it gained informative value. 

Dear Reviewer

Thank you very much for your suggestions to improve the quality of our manuscript. We have made some changes regarding the research design and statistical analysis to response to your comments. Additional reference is cited and added to the list of references accordingly.

The new reference is associated with strength and weak points of the cross-sectional and case-control studies so as to overcome the small number of respondents.

Author Response File: Author Response.docx

Reviewer 3 Report

The revised version of the article improve the quality of data presented and make the information more clear.

Author Response

The revised version of the article improve the quality of data presented and make the information more clear.

Thank you very much for your suggestions to improve the quality of our manuscript. We have made some changes regarding the research design and statistical analysis in response to your comments. Additional reference is cited and added to the list of references accordingly.

The new reference is associated with strength and weak points of the cross-sectional and case-control studies so as to overcome the small number of respondents.

Author Response File: Author Response.docx

Round 3

Reviewer 1 Report

Acceptable.

Author Response

Thank you very much

Author Response File: Author Response.docx