Toll of Chronic Metabolic Acidosis at Molecular, Cellular, and Systemic Levels: A Conceptual Framework to Revisit Type 2 Diabetes (T2D) Pathophysiology
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
The manuscript presents an integrative hypothesis linking chronic metabolic acidosis to the pathophysiology of type 2 diabetes (T2D) at the molecular, cellular, and systemic levels. While conceptually appealing, several sections rely heavily on extrapolation from acute acidosis, non-diabetic models, or unrelated disease contexts. The authors should more clearly distinguish direct experimental evidence, indirect supportive data, and speculative explanations throughout the manuscript. In this context, the conclusion that T2D pathophysiology “largely conforms” to the effects of CMAD appears overstated, particularly given the limited availability of in vivo human tissue pH measurements.
The term chronic metabolic acidosis of diabetes (CMAD) is introduced as a distinct pathological entity; however, standardised clinical diagnostic criteria and validated biomarkers are not clearly defined.
In several places, intracellular acidosis is described both as a cause and a consequence of insulin resistance without a clearly articulated mechanistic sequence, leading to conceptual ambiguity.
A central premise of the review is altered intracellular and interstitial pH across multiple tissues in T2D; however, for several key organs, including adipose tissue, pancreatic interstitium, central nervous system, and lung, the authors acknowledge the absence of direct in vivo pH measurements.
Many conclusions regarding pHi regulation, apoptosis, enzyme activity, and ion conductance are derived primarily from in vitro systems or animal models, yet are frequently extrapolated to human T2D pathophysiology. Clear separation of human clinical evidence from experimental and preclinical data would improve scientific accuracy and credibility.
Greater emphasis should be placed on existing clinical trials, as well as on the limitations and potential adverse effects of bicarbonate or alkalinizing therapies, particularly in patients with renal impairment or cardiovascular comorbidities.
Figure 1, which illustrates pH-sensitive cellular mechanisms (cell cycle, apoptosis, DNA replication, transcription/translation, and ion conductance), appears largely generic. The figure would benefit from clearly highlighting key CMAD–T2D–specific mechanistic links, rather than general pH biology.
Terminology such as pHi, pHn, pHe, intracellular acidity, and tissue acidosis is occasionally used interchangeably, which may confuse readers. Consistent and precise usage is recommended.
The review notes increased β-cell pHi in the presence of extracellular acidosis; however, the mechanistic basis by which this pH gradient contributes to β-cell dysfunction is insufficiently developed and requires clearer justification.
Finally, in several sections, particularly those addressing adipose tissue and the nervous system, direct pH measurements in T2D are lacking, and this limitation should be more explicitly acknowledged when interpreting pathophysiological relevance.
Comments on the Quality of English Language
needs to be improved
Author Response
Reviewer 1.
Comments and Suggestions for Authors
The manuscript presents an integrative hypothesis linking chronic metabolic acidosis to the pathophysiology of type 2 diabetes (T2D) at the molecular, cellular, and systemic levels. While conceptually appealing, several sections rely heavily on extrapolation from acute acidosis, non-diabetic models, or unrelated disease contexts. The authors should more clearly distinguish direct experimental evidence, indirect supportive data, and speculative explanations throughout the manuscript. In this context, the conclusion that T2D pathophysiology “largely conforms” to the effects of CMAD appears overstated, particularly given the limited availability of in vivo human tissue pH measurements.
The term chronic metabolic acidosis of diabetes (CMAD) is introduced as a distinct pathological entity; however, standardized clinical diagnostic criteria and validated biomarkers are not clearly defined.
Res. This review is the last of a series of three reviews, one of which describes the clinical and diagnostic criteria, including the potential biomarkers and management (Giha et al., 2025), to which we referred as a reference. This review is dedicated solely to pathophysiology; if we tried to answer issues outside this theme, the manuscript and list of references would be too long. For that reason, we distributed the topic into 3 review articles.
In several places, intracellular acidosis is described both as a cause and a consequence of insulin resistance without a clearly articulated mechanistic sequence, leading to conceptual ambiguity.
Res. The relationship between IR and CMA is revised throughout the ms. The ambiguity in the relation between IR and CMA will exist until longitudinal cohort studies are carried out to resolve this debate. However, till then, it is fair to say CMA is secondary to IR and that CMA contributes to IR progression, all in a vicious cycle manner (see pages 48-57)
A central premise of the review is altered intracellular and interstitial pH across multiple tissues in T2D; however, for several key organs, including adipose tissue, pancreatic interstitium, central nervous system, and lung, the authors acknowledge the absence of direct in vivo pH measurements.
Res. Yes, we aimed in this review to draw attention to this gap in the literature.
Many conclusions regarding pHi regulation, apoptosis, enzyme activity, and ion conductance are derived primarily from in vitro systems or animal models, yet are frequently extrapolated to human T2D pathophysiology. Clear separation of human clinical evidence from experimental and preclinical data would improve scientific accuracy and credibility.
Res. Totally agree, therefore we state the source of the experimental data when it is known. Unfortunately, not infrequently, the source data is not clearly stated. The available literature showed a big gap regarding the human tissue pH data, which we highlighted in this review. However, we covered most of the published data, irrespective of the accuracy of the source
Greater emphasis should be placed on existing clinical trials, as well as on the limitations and potential adverse effects of bicarbonate or alkalinizing therapies, particularly in patients with renal impairment or cardiovascular comorbidities.
Res. The clinical trials as part of the therapies and the advantages and disadvantages of bicarbonate use were presented before (Giha et al. 2025), however, we added a supplementary table (Table 1-S) listing the acid-neutralizing therapy, and we provided our previous review as a reference for more details about therapy and trials.
Figure 1, which illustrates pH-sensitive cellular mechanisms (cell cycle, apoptosis, DNA replication, transcription/translation, and ion conductance), appears largely generic. The figure would benefit from clearly highlighting key CMAD–T2D–specific mechanistic links, rather than general pH biology.
Res. The figures do not exactly demonstrate the effects of T2D or CMA on cellular mechanisms, but show the normal mechanisms, as a background, while the accompanying comments mention the possible changes in the case of acidosis. Unfortunately no data dedicated to T2D discussing the effect of CMA on these vital functions, while most of the data is generic.
Terminology such as pHi, pHn, pHe, intracellular acidity, and tissue acidosis is occasionally used interchangeably, which may confuse readers. Consistent and precise usage is recommended.
Res. The whole text is now checked to avoid any confusion by using the pH abbreviations interchangeably
Com. The review notes increased β-cell pHi in the presence of extracellular acidosis; however, the mechanistic basis by which this pH gradient contributes to β-cell dysfunction is insufficiently developed and requires clearer justification.
Res. Justification and a reference were added. Based on recent research, the increased B-cell intracellular pH (pHi) in the presence of interstitial (pHn) acidosis, that contributes to beta-cell dysfunction through a complex interplay between metabolic changes, altered excitability, and ion channel dysfunction. Reference: Fang Y, et al., Cytosolic pH is a direct nexus in linking environmental cues with insulin processing and secretion in pancreatic β cells. Cell Metab. 2024;36(6):1237-1251.e4. PMID: 38513648.
Finally, in several sections, particularly those addressing adipose tissue and the nervous system, direct pH measurements in T2D are lacking, and this limitation should be more explicitly acknowledged when interpreting pathophysiological relevance.
Res. Indeed, that is done (lines 741 - 744).
Reviewer 2 Report
Comments and Suggestions for Authors
This review aims to highlight the effects of metabolic acidosis associated with type 2 diabetes, such as cell cycle, apoptosis, and cell growth. Furthermore, this study evaluates the effect of metabolic acidosis on the functions of various organs, including muscle, kidneys, liver, adipose tissue, gut, eye, lung, skin, bone, saliva/teeth, immunity/inflammation, and nervous systems. This is an interesting study given the negative effects of a state of metabolic acidosis on bodily functions. This review requires revision and clarification. 1- The first paragraph of the abstract is too long and I don't think it's necessary. It's important to start by defining this state of metabolic acidosis in relation to respiratory metabolism, the global prevalence of metabolic acidosis, and the interest of this review. 2- It's important to be objective, that is, to describe the causes and effects of the state of metabolic acidosis. 3- Using a graphical abstract is important to briefly explain this review. 4- The first paragraph of the introduction needs improvement by starting with the prevalence of Type 2 Diabetes, which affects more than 700 million people and accounts for 90% of diabetic cases, followed by the causes and effects on health. Then, among these effects, metabolic acidosis (prevalence, negative effects, etc.). 5- Lines 55-56 are more precise, focusing on the cellular level (glycolysis and the Krebs cycle) which are responsible for the production of acids and... proton H+. 6- Line 58, the authors discuss alkalinity? It is important to clearly describe the enzymatic mechanism of either acidity or alkalinity. 7- 6-2. Normal Body pH is clearly described by the pH between the different compartments of the body, but references have been used; only the most relevant references should be used. 8- The title "Physiological pH of the ICF (cytoplasm) and organelles": there is a lot of repetition which diminishes the quality of the manuscript. It is important to describe clearly, briefly, and with the enzyme/hormonal mechanisms that control pH. 9- Tables 1 and 2 describe the same content, so why two tables and not one? 10- Title "Physiological pH of interstitial fluids (ISF) - pHn": avoid repeating the same information in other paragraphs. 11- Lines 130-131 are important for enzyme specificity. 12- Figure 2 is unclear and needs to be redone. 13- Figures 3 are important, but anomalies should be indicated by arrows or other means. 14- Tile "3. Local Effects of Acidosis on Individual Tissues/Organs:" please include each subheading, such as i. Pancreas, ii. Liver..., with its own figure and not all figures together in Figure 3. A. 15- The "Title 4. Therapeutic Potentials of pH Correction in T2D": requires more details on the different therapy strategies. 16- More than 200 references are too many to revise; only the relevant references should be included.
Author Response
Reviewer 2.
Comments and Suggestions for Authors
This review aims to highlight the effects of metabolic acidosis associated with type 2 diabetes, such as cell cycle, apoptosis, and cell growth. Furthermore, this study evaluates the effect of metabolic acidosis on the functions of various organs, including muscle, kidneys, liver, adipose tissue, gut, eye, lung, skin, bone, saliva/teeth, immunity/inflammation, and nervous systems. This is an interesting study given the negative effects of a state of metabolic acidosis on bodily functions. This review requires revision and clarification.
1- The first paragraph of the abstract is too long and I don't think it's necessary. It's important to start by defining this state of metabolic acidosis in relation to respiratory metabolism, the global prevalence of metabolic acidosis, and the interest of this review.
Res. The first paragraph is changed as suggested, and the layout of the whole abstract is revised according to the journal formatting requirements.
2- It's important to be objective, that is, to describe the causes and effects of the state of metabolic acidosis.
Res. Indeed, it's essential to list the possible causes and effects, which are thoroughly discussed in our previous review (Giha, 2023), to which we referred in this view. This topic, CMAD, is covered in a series of three reviews (2 were published, and this is the 3rd review). However, we listed the possible causes (see lines 68, 69 written in red and highlighted in yellow). The three reviews cannot be read separately from each other; otherwise, we end up with a too-long article.
3- Using a graphical abstract is important to briefly explain this review.
Res. Graphic abstract is done, see bottom pages (end of the ms)
4- The first paragraph of the introduction needs improvement by starting with the prevalence of Type 2 Diabetes, which affects more than 700 million people and accounts for 90% of diabetic cases, followed by the causes and effects on health. Then, among these effects, metabolic acidosis (prevalence, negative effects, etc.).
Res. The first paragraph of the introduction is changed to start with the epidemiology of T2D, and the whole introduction is rewritten.
5- Lines 55-56 are more precise, focusing on the cellular level (glycolysis and the Krebs cycle) which are responsible for the production of acids and... proton H+.
Res. Yes, the details were mentioned in (Giha et al., 2023), which is provided here as a reference
6- Line 58, the authors discuss alkalinity? It is important to clearly describe the enzymatic mechanism of either acidity or alkalinity.
Res. Done. The following is added: The pH of the surrounding medium impacts the catalytic activity of an enzyme, primarily by altering its 3D structure and active site conformation (lines 65 – 67).
7- 6-2. Normal Body pH is clearly described by the pH between the different compartments of the body, but references have been used; only the most relevant references should be used.
Res. Apologies for missing what you mean. However, we guess that you mean we used too many references. As readers may be interested in specific tissue compartments or specific pieces of information for in-depth expansion, we provided most of the relevant references. Considering the limited literature on CMAD, every effort was made to incorporate all available relevant data into the reference list."
8- The title "Physiological pH of the ICF (cytoplasm) and organelles": there is a lot of repetition which diminishes the quality of the manuscript. It is important to describe clearly, briefly, and with the enzyme/hormonal mechanisms that control pH.
Res. This section has been rewritten for clarification. However, the ‘control of pH’ is a very huge topic which is beyond the scope of this review; it is covered in the separate 2 reviews (in preparation).
9- Tables 1 and 2 describe the same content, so why two tables and not one?
Res. They are different. Table 1 describes the pH of extracellular fluids, secretions, and excretions, while Table 2 describes the intracellular pH (pHi) in different parenchymal cells of different organs/tissues
10- Title "Physiological pH of interstitial fluids (ISF) - pHn": avoid repeating the same information in other paragraphs.
Res. This section is rewritten; however, the pHn changes in different issues in T2D or CMA need to be mentioned with each tissue, therefore it appears as redundancy, but in fact, the same information is discussed, but for each tissue separately.
11- Lines 130-131 are important for enzyme specificity.
Res. Totally agree.
12- Figure 2 is unclear and needs to be redone.
Res. It is a standard figure in biochemistry books; it describes the effects of insulin and glucagon hormones on the key enzymes of the glycolysis pathway. However, we revised the figure legend for more clarification
13- Figures 3 are important, but anomalies should be indicated by arrows or other means.
Res. The figure on the left side stands for the normal organ/tissue, while the figure of the same organ/tissue in right side of the same row is the abnormal tissue. That is mentioned in the top row; however, this clarification is added to the legend.
14- Tile "3. Local Effects of Acidosis on Individual Tissues/Organs:" please include each subheading, such as i. Pancreas, ii. Liver..., with its own figure and not all figures together in Figure 3. A.
Res. That is exactly what was written; however, the order of the organs/tissues in the text does not follow the order of the figures, at the 3rd level, e.g. 3, A, a, b, c, d, …, for example the pancreas figure 3. B, a and in the text it is discussed before 3, A,. The order of the organs in the text is based on the clinical/pathological significance, at least the first three tissues.
15- The "Title 4. Therapeutic Potentials of pH Correction in T2D": requires more details on the different therapy strategies.
Res. This is a major section in our previously published article, entitled:
Giha HA, Sater MS, Al Qarni AA. Chronic metabolic acidosis of diabetes (CMAD): clinical features, diagnosis, and therapeutic potentials of pH correction. Minerva Endocrinol (Torino). 2025 Jul 10. PMID: 40635456.
However, we provided a supplementary Table 1, as well as the reference, with limited expansion of the text.
16- More than 200 references are too many to revise; only the relevant references should be included.
Res. We agree, but we covered most of the relevant information in the review by providing the appropriate reference without expansion of the text, so that interested readers can find the details in the provided references instead of searching online, e.g., PubMed, which is really laborious work and sometimes not precise. Finding and selecting these references takes a long time and a big effort.
Reviewer 3 Report
Comments and Suggestions for Authors
The pathophysiology of type 2 diabetes is characterised by a vicious cycle involving insulin resistance and pancreatic β-cell dysfunction, as well as adaptive structural and functional changes in insulin-sensitive tissues. Numerous studies have focused on the pathogenesis of type 2 diabetes (T2D), mainly on chronic inflammation (often related to obesity), oxidative stress and the role of mitochondrial dysfunction. However, limited studies have addressed the potential role of chronic metabolic acidosis (CMDA) in T2D. In this context, this manuscript aims to fill this gap by presenting the contribution of CMDA in the pathophysiology of T2D and the systemic consequences of CMDA. Although the manuscript is well-organised and associated with illustrative figures and tables, I have the following suggestions for authors:
- Lines 40-41 - ’’Several studies have reported a relationship between metabolic acidosis and insulin resistance (IR) [4]. Please add additional references in line 41 (multiple studies... but only one reference).
- Please include a Graphical Abstract to summarise the content of the manuscript.
- Please add a reference in lines 60, 73, 74, and 151.
- Please explain all abbreviations and symbols (e.g., ↓) used in Table 1 in its legend.
- Please improve the typographic quality of Figure 1 (mainly page 7). The same suggestion applies to Figure 2.
- Please consider splitting Figures 3a and 3b into multiple figures. Regarding the ’’Chronic myopathy, sarcopenia’’ (title is on page 11, and images are on page 12). In the same figure – in GM dysbiosis, altered motility and drug pharmacokinetics – “ Short villi, reduced mucosal thickness, altered epithelial cell arrangement, presence of mucosal lesions (lymph cell infiltration and vascular fragility)” is not supported by a microscopic image. Some images in this figure are unclear (e.g. oral cavity), and sometimes the text is incomplete (please refer to the microscopic images of skin layers).
- Subchapter 4 is too short. Please include a table summarising potential acid neutralization therapies for CMAD (linked to the previous review).
Author Response
Reviewer 3
Comments and Suggestions for Authors
The pathophysiology of type 2 diabetes is characterised by a vicious cycle involving insulin resistance and pancreatic β-cell dysfunction, as well as adaptive structural and functional changes in insulin-sensitive tissues. Numerous studies have focused on the pathogenesis of type 2 diabetes (T2D), mainly on chronic inflammation (often related to obesity), oxidative stress and the role of mitochondrial dysfunction. However, limited studies have addressed the potential role of chronic metabolic acidosis (CMDA) in T2D. In this context, this manuscript aims to fill this gap by presenting the contribution of CMDA in the pathophysiology of T2D and the systemic consequences of CMDA. Although the manuscript is well-organised and associated with illustrative figures and tables, I have the following suggestions for authors:
Com. Lines 40-41 - ’’Several studies have reported a relationship between metabolic acidosis and insulin resistance (IR) [4]. Please add additional references in line 41 (multiple studies... but only one reference).
Res. All the following references in the paragraph are about the relationship between CMA and insulin resistance; however, references 5 and 6 are added.
Com. Please include a Graphical Abstract to summarise the content of the manuscript.
Res. A graphic abstract is provided at the very bottom of the manuscript (see the last 2 pages).
Com. Please add a reference in lines 60, 73, 74, and 151.
Res. For line 60, we added a reference. For lines 73 and 74, we referred to Table 1, which shows a long list of references. For line 151, the reference is [23], which is added.
Com. Please explain all abbreviations and symbols (e.g., ↓) used in Table 1 in its legend.
Res. Done
Com. Please improve the typographic quality of Figure 1 (mainly page 7). The same suggestion applies to Figure 2.
Res. Unfortunately, we don’t have the technical capacity to improve the typographic quality of the figures; probably the journal's editorial office will do that.
Com. Please consider splitting Figures 3a and 3b into multiple figures. Regarding the ’’Chronic myopathy, sarcopenia’’ (title is on page 11, and images are on page 12).
Res. Technically sounds good to separate Figure 3A and B into multiple small figures; however, the number of the figures will be more than 20, which may not be practical.
Com. In the same figure – in GM dysbiosis, altered motility and drug pharmacokinetics – “ Short villi, reduced mucosal thickness, altered epithelial cell arrangement, presence of mucosal lesions (lymph cell infiltration and vascular fragility)” is not supported by a microscopic image. Some images in this figure are unclear (e.g. oral cavity), and sometimes the text is incomplete (please refer to the microscopic images of skin layers).
Res. Agree, but the figures are copies from different resources to describe the gross normal and abnormal structures rather than diving into the details of the figure. Unfortunately, currently we do not have the software or other technical tools to draw our own diagrams so we rely on the online pictures for a visual description of the target organ/tissue without showing the scientific details as part of the diagram. Apology for this limitation
Com. Subchapter 4 is too short. Please include a table summarising potential acid neutralization therapies for CMAD (linked to the previous review).
Res. A table is provided as supplementary material (S – Table1), with limited expansion in the text about the CMAD therapy, which was presented before (Giha et al., 2025).
Round 2
Reviewer 1 Report
Comments and Suggestions for Authors
The main focus of the review is that chronic metabolic acidosis is a major driver of the pathophysiology of type 2 diabetes (T2D), which is ambitious but insufficiently supported by scientific evidence. The manuscript relies heavily on models of acute acidosis, extrapolations from non-diabetic systems, and in vitro findings. Human evidence is not clearly separated from speculative interpretation, and the magnitude of pH changes typically observed in T2D is not quantitatively framed to justify the proposed systemic effects.
The authors have not adequately resolved the directionality of causation between insulin resistance (IR) and acidosis, and there is an insufficient amount of in vivo human pH data in key organs, including adipose tissue, CNS, and pancreatic β-cells, to support the authors’ mechanistic assertions.
The authors have failed to integrate critical molecular mediators that connect the effect(s) of pH shifts on signaling pathways, and discussions about the therapeutic relevance of pH modulation do not consider key risk factors that must be taken into account.
Furthermore, several of the figures appear to be reproduced or adapted from other literature sources and are not representative of what would be expected of a quality review article. Considering the numerous conceptual, evidential, and presentation-related issues, the manuscript in its current form is not suitable for publication.
Comments on the Quality of English Language
needs to be improved
Author Response
Response to reviewers’ comments:
Manuscript title: Toll of Chronic Metabolic Acidosis at Molecular, Cellular, and Systemic Levels: An Initiative to Revisit Type-2 Diabetes (T2D) Pathophysiology
Reviewer 1, round 2.
Comment
The main focus of the review is that chronic metabolic acidosis is a major driver of the pathophysiology of type 2 diabetes (T2D), which is ambitious but insufficiently supported by scientific evidence.
Response
We appreciate the reviewer’s concern regarding potential overstatement. While the manuscript did not explicitly describe chronic metabolic acidosis (CMA) as a “major driver” of T2D, we recognize that some wording may have conveyed a strong causal implication. To address this, we have revised the manuscript throughout to adopt more cautious and precise language (e.g., “potential role,” “possible contribution,” “may contribute”). All such modifications are highlighted in green in the revised version.
Comment
The manuscript relies heavily on models of acute acidosis, extrapolations from non-diabetic systems, and in vitro findings.
Response
We appreciate this concern. Our intention was to discuss chronic metabolic acidosis rather than acute acidosis. To improve clarity, we carefully re-examined the manuscript and to ensure there is clear distinction between acute and chronic acidosis. It is worth mentioning that the sources of the protons (ketone bodies and lactic acid) are the same in both acute and chronic acidosis; the differences are in the mode of onset, quantity, and continuity.
The introduction is basically about the effects of CMA at the molecular, cellular, and systemic levels, regardless of the cause. However, these effects of CMA, to a large extent, are aligned with pathophysiological features recognized in T2D.
We agree that in vitro studies do not necessarily reflect what happened in vivo; however, citing results from in vitro studies is justified in all types of articles, and this review is no exception.
Comment
Human evidence is not clearly separated from speculative interpretation, and the magnitude of pH changes typically observed in T2D is not quantitatively framed to justify the proposed systemic effects.
Response
The magnitude of pH changes in T2D, as in several chronic disorders associated with CMA, is generally described in the literature as “mild acidosis.” The potential pathophysiological relevance of CMA is further supported by reported clinical responses to acid-neutralization therapies (see Supplementary Table 1-S and Giha et al., 2025). Some of these disorders are closely related to T2D clinically or biochemically, while others represent common T2D comorbidities.
To the best of our knowledge, the biological effects of pH changes depend not only on absolute pH values but also on the specific organ or tissue involved, the compartment affected (extracellular, intracellular, or organellar), and the cellular context (e.g., stage of the cell cycle). In the revised manuscript, we have highlighted in green examples of pH variations reported to exert measurable effects.
While quantitative framing can be informative, biological responses are not always determined solely by the magnitude of change. In some contexts, parameters are inferred from their functional consequences rather than absolute values (see lines 335–336). Numerous studies describe CMA as clinically relevant mild acidosis, even when precise quantitative thresholds are not consistently defined.
Comment
The authors have not adequately resolved the directionality of causation between insulin resistance (IR) and acidosis, and there is an insufficient amount of in vivo human pH data in key organs, including adipose tissue (AT), CNS, and pancreatic β-cells, to support the authors’ mechanistic assertions.
Response
The relationship between IR and CMA is thoroughly discussed in this review, incorporating up-to-date information (see lines 46–57, highlighted in green). The cause–effect relationship between IR and CMA remains debatable; however, evidence supports the existence of a potential vicious cycle between the two.
We agree that pH data from adipose tissue (AT), muscle, CNS, and other organs in T2D are limited. Nevertheless, the available evidence is sufficient to suggest an association between T2D and CMA, which is acknowledged at the end of the Discussion. Importantly, one of the objectives of this review is to highlight these gaps in the literature and encourage further investigation.
Comment
The authors have failed to integrate critical molecular mediators that connect the effect(s) of pH shifts on signaling pathways, and discussions about the therapeutic relevance of pH modulation do not consider key risk factors that must be taken into account.
Response
We respectfully disagree with the reviewer’s assessment that the molecular mediators linking CMA to signaling pathways were not adequately addressed. These mechanisms are discussed in several sections of the manuscript (lines 50–53, 140–144, 230–232, 378–382, 428–430, 776–778, and 789–790), where we describe how pH alterations may influence key molecular and signaling pathways. In the revised version, we have further clarified and strengthened these sections to improve integration and readability.
Given the breadth of this topic, we have aimed to provide a focused yet representative discussion of major mechanistic pathways relevant to T2D pathophysiology. We would welcome specific suggestions from the reviewer regarding additional mediators that should be incorporated to further strengthen this section.
Regarding therapeutic considerations, we have added Supplementary Table 1-S summarizing relevant studies on acid-neutralization strategies. For a more detailed discussion of therapeutic approaches and associated risks, we have referenced our recent review (Giha et al., 2025). As the primary objective of the present manuscript is to examine the pathophysiological role of CMA in T2D, an extensive discussion of therapeutic strategies is beyond its intended scope; however, we have ensured that key references are provided for readers seeking further detail.
Comment
Furthermore, several of the figures appear to be reproduced or adapted from other literature sources and are not representative of what would be expected of a quality review article.
Response
The review contains three figures: two composite figures (Figure 1 and Figure 3A–B) incorporating a total of 43 visual elements, and one standalone schematic diagram (Figure 2). Figures 2 and 3 are organized into thematic blocks, each combining visual components with explanatory text to facilitate conceptual integration. The composite figures were intentionally designed to synthesize visual material from diverse educational and scientific sources into cohesive, review-specific frameworks that support interdisciplinary understanding. Most visual elements are derived from publicly available educational or teaching resources (e.g., Mayo Clinic materials), while a limited number originate from published scientific articles. All sources are clearly acknowledged in the figure legends and reference list to ensure proper attribution and transparency. Notably, e Each individual visual element, when considered in isolation, does not represent the central contribution of this review; rather, their integration into unified conceptual schematics is intended to enhance clarity and accessibility. Proper citation has been provided throughout to respect authorship and intellectual property standards.
Reviewer 3 Report
Comments and Suggestions for Authors
The quality of the manuscript has improved with details and clarifications. I recommend the paper for publication in its present form.
Author Response
We sincerely thank the reviewer for the careful evaluation of our manuscript and for recognizing the improvements made in the revised version. We greatly appreciate the positive feedback and recommendation for publication.
