The Potential Effects of ACE Inhibitors on the Severity of Periodontal Disease-Related Attachment Loss: An Observational, Cross-Sectional Comparative Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

After reviewing the manuscript with oral identification number 3866708, we have the following comments and suggestions for this round of review.

In the title

It is suggested that this be modified. The authors reach a conclusion that is not reflected in the title. They focus on the loss of attachment, and this could be stated directly in the title. Furthermore, the authors mention ‘periodontal disease’ in the title, but nowhere in the document is it indicated how this diagnosis was reached.

In the abstract 
It is suggested that this be modified. The objective of the study indicated here differs greatly from that shown in the last section of the introduction. In the methods, it is suggested that the statistical test applied be indicated. In the results, include the p-value of the test of interest. In the conclusions, the authors mention ‘incidence,’ but do not establish how the diagnosis of periodontal disease was made. 

In keywords

It is suggested to include ‘Loss of attachment’, following MeSH terms.

In the introduction 

In lines 114-119, it is suggested that the general objective and hypothesis be modified. The general objective and specific objectives, if any, should be improved.  
The hypothesis proposed goes beyond the scope of the manuscript, as there is no measurement of proinflammatory mediators or evaluation of the metabolism of bradykinin and substance P. 

In materials and methods.

A detailed review of the type and design of the study is suggested. A case-control study needs to specify in detail the characteristics of each group and the conditions for selecting cases and controls, define whether they are matched or not, and specify a sample size and a specific sampling method. In any case, the document could be executed as an observational, cross-sectional comparative study. 

It is unclear whether the data used came solely from the clinical history and records of each patient. If so, it is suggested that the periodontal disease diagnosis guidelines applied at the time be indicated, since it is mentioned that these are patients treated in the last 10 years. 

At the same time, it should be indicated whether the most current consensus for the diagnosis of periodontal disease was followed. This is crucial, especially because they attempt to relate the severity of periodontal disease to the prescription of ACE inhibitors.

It should be indicated which normality tests were applied to the data. 

In results
It is suggested that these be modified. There is no table presenting the general characteristics of the patients analysed, nor is there any relevant information on each group (gender, age, habits, systemic diseases, etc.).

In each figure, it is suggested to indicate and place the p-value obtained, either directly in the image or by specifying it in the figure caption. Not just the asterisk. 

Each table suggests indicating and entering the p value obtained for each test. 

In the discussion
This section may change according to the modifications made, taking into account the above indications. 

Authors should be careful when stating, ‘This is the first study to report between ACE inhibitors and their potential to exacerbate the inflammatory process associated with periodontal disease.’ Clearly, it is not the first, and there is extensive literature on the subject, both directly and indirectly. We suggest revising this section.

The limitations of the study should be indicated, along with how the authors managed to minimise their impact on the results of the manuscript. 

In the conclusions
Modification is suggested. ACE inhibitors are not exclusively used for cardiovascular diseases. Furthermore, in the materials and methods, the authors do not indicate how they obtained the data on whether or not the patients had cardiovascular disease. Furthermore, the authors state, ‘This suggests that patients with impaired periodontal health, and being prescribed ACE inhibitors, should be treated as an “at risk” population, requiring a more timely and vigorous intervention.’ How can they know that a more vigorous and consistent intervention is needed if they do not specify the classification of periodontal disease? The results should not be overestimated, and the authors should limit themselves to considering what was actually obtained in the results according to the type and design of the study. 

 

Author Response

Firstly we would like to thank you for the time and care you have taken in reviewing this manuscript, and for the constructive feedback you have provided to us. We have tried to take all you feedback on board in order to improve the manuscript. In terms of the specific points:

1. In the title It is suggested that this be modified. The authors reach a conclusion that is not reflected in the title. They focus on the loss of attachment, and this could be stated directly in the title.

We agree. We have amended the title to "The Potential Effects of ACE Inhibitors on the Severity of Periodontal Disease-Related Attachment Loss; an Observational, Cross-Sectional Comparative Study" in order to address both your point around what was objectively assessed, as well as your latter point on study design.

In the abstract  It is suggested that this be modified. The objective of the study indicated here differs greatly from that shown in the last section of the introduction.

Again, we agree, and we have modified the abstract to directly reflect what was actually measured -  "The objective in the abstract has been changed to: may have an influence on the severity of periodontal disease, as assessed by clinical attachment loss"

In the methods, it is suggested that the statistical test applied be indicated. In the results, include the p-value of the test of interest. Again, we agree, and we have tried to clarify the approach to analysis in the methods - "

"A two-way analysis of variance was performed to assess whether there was any associa-tion between the extent of clinical attachment loss (CAL 1-3mm; CAL 4-5mm; CAL >6mm) and the patient’s antihypertensive medication (no antihypertensive medication; ACE in-hibitor; other antihypertensive medication). The two-way ANOVA indicated that medica-tion had a significant effect on results (P<0.0001). A comparison between the three medi-cation groups was performed using a one-way analysis of variance followed by post-test analysis using Newman-Keuls Multiple Comparison Test. A p value of < 0.05 was taken as being statistically significant. In the conclusions, the authors mention ‘incidence,’ but do not establish how the diagnosis of periodontal disease was made."

In the conclusions, the authors mention ‘incidence,’ but do not establish how the diagnosis of periodontal disease was made.

We appreciate this point, so we have both clarified the diagnosis of periodontitis in the methods, whilst also ensuring that we are more precise in describing what was actually assessed in the results and discussion. In the methods we now state "

The initial cohort selection was undertaken by examining the clinical history and records of patients who had attended the specialist periodontist clinic in the preceding 10 years (2003-2012), and who had received a positive diagnosis of periodontal disease. Diagnosis was completed following comprehensive periodontal examination including clinical examination, periodontal charting, radiographic examination and assessment of medical history. A positive diagnosis was based on the American Academy of Periodontology Consensus Guidelines [38]. Whilst the diagnostic labelling nomenclature has changed, the diagnostic procedures and processes have not [39]. Initial identification of the study cohort was done on the basis of identifying patients who had been diagnosed with periodontitis, and were on any prescribed medication. Any patient records, which indicated that the patient was a current or previous smoker, were automatically excluded from the study. In addition, patients with a diagnosed systemic medical condition known to have a significant impact on periodontal health, such as diabetes mellitus, were also excluded from the study. Patient data was sorted into three groups according to prescribed antihypertensive medication: patients being prescribed ACE inhibitors to manage hypertension, patients being prescribed another class of anti-hypertensive medication, and patients being prescribed no antihypertensive medication. For the purposes of the study, the patients taking other antihypertensive medications were viewed as a positive control for the potential effects of medication-induced xerostomia [40]."

In keywords It is suggested to include ‘Loss of attachment’, following MeSH terms. We agree, and we have included that.

In the introduction In lines 114-119, it is suggested that the general objective and hypothesis be modified. The general objective and specific objectives, if any, should be improved. The hypothesis proposed goes beyond the scope of the manuscript, as there is no measurement of proinflammatory mediators or evaluation of the metabolism of bradykinin and substance P. 

We agree, and we have tried to ensure that the hypothesis and objectives align with what was actually measured. 

We have modified the objectives and hypothesis

 The aim of the present study was to evaluate whether ACE inhibitors may have a po-tential influence on the severity of periodontal disease-related attachment loss. It is recog-nised that in periodontal disease, the inflammatory-mediated bone reabsorption results from an imbalance between pro- and anti-inflammatory mediators [6]. Whilst a range of inflammatory mediators are considered to play a role in this, two peptide mediators, sub-stance P and bradykinin, have been identified as having a potential pro-inflammatory role [28, 36]. Given that ACE inhibitors are known to increase the levels of substance P and bradykinin, as a result of reduced metabolism, we hypothesised that ACE inhibitors may have the po-tential to exacerbate periodontal disease [37].

In materials and methods. A detailed review of the type and design of the study is suggested. A case-control study needs to specify in detail the characteristics of each group and the conditions for selecting cases and controls, define whether they are matched or not, and specify a sample size and a specific sampling method. In any case, the document could be executed as an observational, cross-sectional comparative study. 

We agree, and we have amended this in both the title and materials and methods.

It is unclear whether the data used came solely from the clinical history and records of each patient. If so, it is suggested that the periodontal disease diagnosis guidelines applied at the time be indicated, since it is mentioned that these are patients treated in the last 10 years. 

At the same time, it should be indicated whether the most current consensus for the diagnosis of periodontal disease was followed. This is crucial, especially because they attempt to relate the severity of periodontal disease to the prescription of ACE inhibitors.

We agree, and this has been included in the methods as indicated earlier.

It should be indicated which normality tests were applied to the data. 

Yes, we agree, and we have now mentioned that the Shapiro-Wilk test was utilised 

In results
It is suggested that these be modified. There is no table presenting the general characteristics of the patients analysed, nor is there any relevant information on each group (gender, age, habits, systemic diseases, etc.).

We can see the value of this point, so we have provided a table of the general cohort characteristics that were recorded (now Table 1). Unfortunately some of this data was not recorded.

In each figure, it is suggested to indicate and place the p-value obtained, either directly in the image or by specifying it in the figure caption. Not just the asterisk. Each table suggests indicating and entering the p value obtained for each test. 

We have tried to clarify the statistical results within the figure legends in order to address this point.

In the discussion
This section may change according to the modifications made, taking into account the above indications. 

Authors should be careful when stating, ‘This is the first study to report between ACE inhibitors and their potential to exacerbate the inflammatory process associated with periodontal disease.’ Clearly, it is not the first, and there is extensive literature on the subject, both directly and indirectly. We suggest revising this section.

We would like to apologize for this. We believe it was true when this manuscript was first drafted, but as you point out, that is no longer the case. This has been amended within the manuscript.  

The limitations of the study should be indicated, along with how the authors managed to minimise their impact on the results of the manuscript. 

We agree, and we have tried to address the study limitations, as well as the scope and value for future studies in this  area.

In the conclusions
Modification is suggested. ACE inhibitors are not exclusively used for cardiovascular diseases.

Yes, we agree, so we have tried to be more careful in describing the breadth of clinical utility of ACE inhibitors.

Furthermore, in the materials and methods, the authors do not indicate how they obtained the data on whether or not the patients had cardiovascular disease.

We appreciate this point, so we have now clarified that the patients in this study were receiving ACE inhibitors to manage diagnosed hypertension

Furthermore, the authors state, ‘This suggests that patients with impaired periodontal health, and being prescribed ACE inhibitors, should be treated as an “at risk” population, requiring a more timely and vigorous intervention.’ How can they know that a more vigorous and consistent intervention is needed if they do not specify the classification of periodontal disease? The results should not be overestimated, and the authors should limit themselves to considering what was actually obtained in the results according to the type and design of the study.

We appreciate this point, and we have tried to ensure that we do not "over reach" on the conclusions from this study.

 

Again, we would like to thank you for the time you have taken in providing your feedback.

 

Kind regards, Alan

Reviewer 2 Report

Comments and Suggestions for Authors

The minor revision is recommended. However, several points still need clarification:

1. In Page 2 Line 57 (Introduction), the word "of" is missing after "expression". Please add it to ensure grammatical accuracy. Additionally, please check the grammar throughout the entire manuscript and correct any existing mistakes.
2. In Page 5 Line 168 (Results), the author compares the percentage of bleeding upon probing between the three groups. However, the manuscript does not state how many measurement sites were assessed per patient. Please provide this number to help readers understand the data.
3. In Page 6 Line 208 (Results), Table 1 shows the data of the clinical attachment level for the three groups. The table lacks a note on whether the “mean ± SEM” values were rounded. Please add this detail to ensure data accuracy.
4. This article only discusses the impact of cardiovascular drugs on periodontitis. Additionally, analysis based on the database shows that tooth loss because of the severe periodontitis, is closely related to cardiovascular diseases and aging. Please discuss it in the manuscript. These articles maybe helpful:

                    doi: 10.1016/j.jdent.2022.104178.

                    doi: 10.1016/j.amjmed.2023.04.008.

Author Response

Firstly we would like to thank you for the time you have take to review our manuscript, and for the constructive feedback you have provided to us.

1. In Page 2 Line 57 (Introduction), the word "of" is missing after "expression". Please add it to ensure grammatical accuracy. Additionally, please check the grammar throughout the entire manuscript and correct any existing mistakes.

Thank you for picking this up. this has now been amended, and we have tried to ensure grammatical correctness.

1. In Page 5 Line 168 (Results), the author compares the percentage of bleeding upon probing between the three groups. However, the manuscript does not state how many measurement sites were assessed per patient. Please provide this number to help readers understand the data.

Again, thank you for pointing this out. We have now included in the methods "All periodontal measurements were taken on six surfaces per tooth, and all measurements were performed by a single periodontist.

1. In Page 6 Line 208 (Results), Table 1 shows the data of the clinical attachment level for the three groups. The table lacks a note on whether the “mean ± SEM” values were rounded. Please add this detail to ensure data accuracy.

This is  a good point, and we have now included a statement that the results were rounded to one decimal place.

1. This article only discusses the impact of cardiovascular drugs on periodontitis. Additionally, analysis based on the database shows that tooth loss because of the severe periodontitis, is closely related to cardiovascular diseases and aging. Please discuss it in the manuscript. These articles maybe helpful:

                    doi: 10.1016/j.jdent.2022.104178.

                    doi: 10.1016/j.amjmed.2023.04.008

Firstly, thank you for the links to these articles. There is certainly a significant interplay between oral health and cardiovascular disease. We have now broadened that aspect in our discussion.

We thank you again for your time and constructive feedback.

Kind regards, Alan

Reviewer 3 Report

Comments and Suggestions for Authors

Reviewer's Report

Manuscript ID: oral-3866708

Title:  The Potential Effects of ACE Inhibitors on the Severity of Periodontal Disease; a Retrospective Case-Control Study

Overall Recommendation: Minor Revisions

General Comments:

Thank you for the opportunity to review this interesting and clinically relevant manuscript. The study addresses an important question regarding the potential impact of a widely prescribed class of antihypertensive drugs on periodontal health. The hypothesis that ACE inhibitors could exacerbate periodontitis through the accumulation of pro-inflammatory mediators is well-articulated and biologically plausible.

The case-control design is appropriate for an initial investigation of this association. A significant strength of the study is the inclusion of a control group on other antihypertensive medications, which helps to isolate the effect of ACE inhibitors from the potential confounding effects of hypertension itself or side effects like xerostomia common to other drugs. Furthermore, having all periodontal measurements performed by a single, calibrated periodontist enhances the internal consistency and reliability of the clinical data.

The results suggesting a higher incidence of severe attachment loss in ACE inhibitor users are intriguing and merit discussion. To further strengthen the manuscript and ensure its conclusions are appropriately contextualized, I recommend adding a paragraph to the discussion section to openly acknowledge the following inherent limitations of the retrospective design. Addressing these points will improve the manuscript's transparency and scholarly rigor.

Specific Comments for the Authors:

1. Sample Size and Statistical Power:
   The sample size, particularly in the medication groups (n=19 each), is relatively modest. While the findings for the primary outcome (CAL >6mm) are statistically significant, the study may have been underpowered to detect more subtle differences in other parameters, such as bleeding on probing or moderate attachment loss (CAL 4-5mm), where trends were observed but did not reach significance. It would be valuable to include a comment on this limitation, noting that the results should be considered preliminary and that larger-scale studies are needed to confirm these findings and explore trends that may have been missed.
2. Duration of Medication Use and Hypertension Control:
   As a retrospective study based on records, data on two important factors were likely unavailable: the duration of ACE inhibitor (or other antihypertensive) therapy and the degree of hypertension control. It is plausible that the duration of exposure to the drug influences its effect on the periodontium. Furthermore, the severity and control of hypertension itself could be a confounding variable. The authors should acknowledge the absence of this data as a limitation and suggest that future prospective studies aim to record these parameters to provide a more nuanced analysis.
3. Focus on Epidemiological Association:
   The discussion does an excellent job of exploring the potential biological mechanisms (e.g., bradykinin, substance P) that could explain the observed association. However, as this is an epidemiological study that did not measure these inflammatory mediators directly, the mechanism remains speculative. To ensure perfect clarity for the reader, I suggest slightly moderating the language in the discussion to emphasize that the study demonstrates an association, and that the proposed pathway is a hypothesis generated from the results. While the discussion on animal models (e.g., TLR2 knockouts) is interesting, it might be slightly tangential; a tighter focus on the human clinical findings would strengthen the argument.

Conclusion:

This is a valuable study that highlights a potential and previously under-investigated side effect of ACE inhibitors. The authors are to be commended on their work. By incorporating a brief and candid discussion of the limitations mentioned above, the manuscript will become more balanced and robust, providing a solid foundation for future research in this area. I believe these changes can be made without the need for additional data analysis or resubmission.

Thank you again for inviting me to review this manuscript.

Comments for author File: Comments.pdf

Author Response

Firstly we would like to thank you for the time and care you have taken in reviewing our manuscript, and for the constructive feedback you have provided to us.

Specific Comments for the Authors:

I recommend adding a paragraph to the discussion section to openly acknowledge the following inherent limitations of the retrospective design. Addressing these points will improve the manuscript's transparency and scholarly rigor.

Thank you for that point. We agree, and have now tried to provide a clear statement outlining the study limitations.

1. Sample Size and Statistical Power:
   The sample size, particularly in the medication groups (n=19 each), is relatively modest. While the findings for the primary outcome (CAL >6mm) are statistically significant, the study may have been underpowered to detect more subtle differences in other parameters, such as bleeding on probing or moderate attachment loss (CAL 4-5mm), where trends were observed but did not reach significance. It would be valuable to include a comment on this limitation, noting that the results should be considered preliminary and that larger-scale studies are needed to confirm these findings and explore trends that may have been missed.

Yes, this is an important point, so again we have tried to recognize this as a limitation of the study size.

1. Duration of Medication Use and Hypertension Control:
   As a retrospective study based on records, data on two important factors were likely unavailable: the duration of ACE inhibitor (or other antihypertensive) therapy and the degree of hypertension control. It is plausible that the duration of exposure to the drug influences its effect on the periodontium. Furthermore, the severity and control of hypertension itself could be a confounding variable. The authors should acknowledge the absence of this data as a limitation and suggest that future prospective studies aim to record these parameters to provide a more nuanced analysis.

Again, we agree that these are all important points, and could well have an influence on the results. Unfortunately, given the retrospective nature of the study, we are not in a position to now gather that information. However, we have now clearly indicated that it is a limitation of the study.

1. Focus on Epidemiological Association:
   The discussion does an excellent job of exploring the potential biological mechanisms (e.g., bradykinin, substance P) that could explain the observed association. However, as this is an epidemiological study that did not measure these inflammatory mediators directly, the mechanism remains speculative. To ensure perfect clarity for the reader, I suggest slightly moderating the language in the discussion to emphasize that the study demonstrates an association, and that the proposed pathway is a hypothesis generated from the results. While the discussion on animal models (e.g., TLR2 knockouts) is interesting, it might be slightly tangential; a tighter focus on the human clinical findings would strengthen the argument.

Again, we agree with this point, so we have tried to amend the discussion to more clearly align it with the results that were obtained. In response to another reviewer, we have also built in more of a discussion around the relationship between oral health and cardiovascular disease.

We would like to thank you again for the time and care you have taken in reviewing our manuscript.

Kind regards, Alan 

Reviewer 4 Report

Comments and Suggestions for Authors

This paper, titled "Potential effect of ACE inhibitors on the severity of periodontal diseases: a Retrospective case-control study," aimed to analyze patient records from a periodontal specialty practice, primarily focused on the loss of attachment to determine the influence of ACE inhibitors on the severity of periodontal disease. Periodontal disease severity was assessed using Clinical Attachment Level measurements. The study exclusively included non-smokers to standardize baseline data. Data were collected from patients receiving ACE inhibitors, another group on different anti-hypertensive medications, and a third group not taking any anti-hypertensive medication.

This manuscript details the crucial role of ACE receptors (found throughout the body) in various diseases and their functions. Given hypertension's widespread prevalence, long-term drug intake impacts systemic health. Despite their primary role in hypertension control, ACE receptors are abundant in many tissues performing diverse functions that can mitigate structural damage. Co-morbidities like hypertension and diabetes can worsen periodontal disease. This study is an excellent initiative for data sharing, providing thoroughly detailed and well-balanced data, meticulously collected with inclusion and exclusion criteria.

Kindly address the following comments and provide your responses:

1. Since only one periodontist collected data (line 146–147), there is potential for observer bias, which could affect consistency and introduce detection bias.
2. While the study offered foundational data on non-smokers, several potential confounding factors, including diabetic status, ACE inhibitor dosage and duration, and other comorbidities affecting periodontal status in the relevant age group, were not explicitly detailed. The correlation between the inflammatory cytokines mentioned in the study and diabetics has been noted on line 298. Furthermore, information concerning blood pressure and dosage levels for patients was not clearly presented.
3. The study centers on pro-inflammatory and anti-inflammatory mediators. The authors have effectively articulated the connections; however, a simplified flow diagram detailing this information would enhance reader comprehension prior to or during the reading process. The absence of biochemical data on mediator levels limits the mechanistic strength of the conclusions.
4. Potential side effects of antihypertensive medication, such as xerostomia and its associated impacts on oral health, are mentioned in line 253; however, the study did not quantify any data regarding these effects.

The authors are encouraged to address these comments in detail. If data are unavailable, the authors should at least discuss their implications as study limitations and highlight directions for future research recommendations. 

Overall, this manuscript represents a valuable scientific contribution, offering new insights into ACE receptor functions and their broader clinical influences. The initiative for sharing such well-curated data is commendable, and the findings are likely to be of interest to both clinicians and researchers working at the interface of systemic and oral health. 

Author Response

Firstly, we would like to thank you for the time and care you have taken in reviewing our manuscript, and for the constructive feedback you have provided to us.

In terms of the specific points you have raised:

Since only one periodontist collected data (line 146–147), there is potential for observer bias, which could affect consistency and introduce detection bias.

We appreciate this point, and we see it as a bit of a "double-edged sword". For a small study, having just one specialist does remove inter-clinician variability, but it does mean that clinical judgements are from a single perspective. We have addressed this point in our discussion of the study limitations.

1. While the study offered foundational data on non-smokers, several potential confounding factors, including diabetic status, ACE inhibitor dosage and duration, and other comorbidities affecting periodontal status in the relevant age group, were not explicitly detailed. The correlation between the inflammatory cytokines mentioned in the study and diabetics has been noted on line 298. Furthermore, information concerning blood pressure and dosage levels for patients was not clearly presented.

We agree that factors like drug dosing, duration of treatment and how effective the hypertensive control is would represent valuable information, and the lack of this is one of the limitations of this study, and has now been stated as such. In terms of co-morbidities, the study did exclude patients with the more obvious issues, such as smoking and diabetes.

1. The study centers on pro-inflammatory and anti-inflammatory mediators. The authors have effectively articulated the connections; however, a simplified flow diagram detailing this information would enhance reader comprehension prior to or during the reading process. The absence of biochemical data on mediator levels limits the mechanistic strength of the conclusions.

Again, this is one of the limitations of the study design. We have both acknowledged this, as well as highlighting the value of undertaking a prospective study where such data could be monitored. We have also tried to ensure that we do not "over-reach" on our conclusions, given the absence of such supporting data.

1. Potential side effects of antihypertensive medication, such as xerostomia and its associated impacts on oral health, are mentioned in line 253; however, the study did not quantify any data regarding these effects.

Again, this is a study limitation, since such data, either subjective or objective is not available to us. We have both highlighted this limitation, as well as indicated that a prospective study where such data could be gathered would be valuable.

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript shows improvement in this round of revision and can now be considered for publication. The authors' commitment and dedication to addressing the suggestions aimed at improving their hard work are evident. 

Reviewer 4 Report

Comments and Suggestions for Authors

Authors have responded and made corrections as appropriate based on the comments raised.

The revised manuscript effectively aligns with the subject matter, and the scientific evidence is now presented with greater clarity. Limitations have been added, which strengthen the study report and encourage future research to rectify these limitations. 

The manuscript represents a valuable scientific contribution, offering new insights into ACE receptor functions and their broader clinical influences. The initiative for sharing such well-curated data is commendable, and the findings are likely to be of interest to both clinicians and researchers working at the interface of systemic and oral health.