Assessment of Psoas Muscle Index in Middle-Aged Type 2 Diabetes Patients: Impact of Insulin Therapy on Sarcopenia
Round 1
Reviewer 1 Report (Previous Reviewer 1)
Comments and Suggestions for Authors I have read through the manuscript, and the necessary changes have been made. I have no concerns about releasing the paper for publication.Author Response
Comments 1: I have read through the manuscript, and the necessary changes have been made. I have no concerns about releasing the paper for publication.
Response 1: Thank you for your thorough review and for your positive feedback.
Reviewer 2 Report (Previous Reviewer 2)
Comments and Suggestions for AuthorsI still have some comments:
1. The term sarcopenia should not be used in the title and throughout the text when referring to the included patients, since the diagnosis sarcopenia was never confirmed in patients, therefore, it is misleading.
Author Response
Comments 1: The term sarcopenia should not be used in the title and throughout the text when referring to the included patients, since the diagnosis sarcopenia was never confirmed in patients, therefore, it is misleading.
Response 1: We appreciate your concerns about the use of the term "sarcopenia" in the title and text.
Our purpose in choosing the word “sarcopenia” was to highlight the broader background of muscle mass loss in T2DM patients and the possible relevance of Psoas Muscle Index (PMI) as a marker of sarcopenia. We acknowledge that, due to the retrospective nature of our study, the diagnosis of sarcopenia could not be clinically confirmed in the individuals included, and we did not intend to suggest otherwise.
By using the term "sarcopenia" in the title of our article and throughout the article, we aimed to underline the necessity of muscle mass evaluation in order to better understand the consequences of muscle mass loss in T2DM patients. In this context, the term "sarcopenia" better reflects the purpose and scope of our research. A more accurate definition and direct evaluation of the diagnosis of sarcopenia in line with clinical diagnostic criteria may be advantageous in future studies.
Thank you for your attention and understanding.
Reviewer 3 Report (Previous Reviewer 3)
Comments and Suggestions for AuthorsDear,
after the corrections made, the manuscript tomography-3085487 meets the high criteria to be published in the journal Tomography.
Kind regards
Author Response
Comments 1:
Dear,
after the corrections made, the manuscript tomography-3085487 meets the high criteria to be published in the journal Tomography.
Kind regards
Response 1: Thank you for your thorough review and for your positive feedback.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe retrospective study investigates the role of insulin therapy on muscle preservation in T2DM and sarcopenia. The Materials and Methods section is robust but could benefit from a more deeper evaluation of non-contrast abdominal CT scans for muscle assessment and a comparison of psoas muscle density (PMD) with other muscle regions in the same patient. The Discussion interprets results well, highlighting insulin therapy's effects on psoas muscle index (PMI) and conclusively discusses sarcopenia, insulin resistance, and therapy benefits, supported by the findings.
Comments for author File: 
Comments.pdf
Author Response
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.
Comment: The study’s ethical permit number is missing.
Response: The ethical permit number is included within the manuscript.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors studied the psoas muscle index via CT in middle-aged T2DM patients on insulin therapy vs. oral therapy and controls. The manuscript is interesting, however, I have a few comments.
1. Why did the patients undergo a non-contrast CT of abdomen?
2. The authors imply in the title that they studied sarcopenia, however, the patients were not diagnosed with sarcopenia. So the term sarcopenia should not be used.
3. Comparing T2DM patients on insulin and OAD may not be appropriate, since the difference in treatment is probably due to severity of the disease. It also implies that insulin patients were probably better self-monitored and were better involved in the treatment of diabetes. Better design would be to study the same person before and after starting the insulin treatment.
4. Do the authors have any data about the physical activity of the patients in both groups?
5. How did the authors verify that the control patients did not have diabetes or pre-diabetes?
6. Did any of the patients also suffered from osteopenia or any of the complications of diabetes?
7. The study ethical permit Number is missing.
Author Response
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.
Comment 1: Why did the patients undergo a non-contrast CT of the abdomen?
Response: The patients underwent non-contrast CT scans of the abdomen for a variety of clinical reasons, including symptoms such as abdominal pain, suspected kidney stones, and other abdominal conditions that necessitate imaging for accurate diagnosis and treatment planning. The non-contrast CT was specifically chosen to prevent the influence of contrast agents on muscle attenuation measurements, ensuring more reliable and accurate assessment of muscle mass (Shen et al., 2004; Durand et al., 2014). This approach allows for clear visualization and evaluation of the psoas muscle, which is critical for calculating the Psoas Muscle Index (PMI).
Comment 2: The title implies that the study focused on sarcopenia, but the patients were not diagnosed with sarcopenia. The term sarcopenia should not be used.
Response: While the term "sarcopenia" is indeed used in the title to reflect the broader context of muscle mass loss in T2DM patients, it is important to clarify that the study's primary aim was to evaluate the Psoas Muscle Index (PMI) as a potential marker for sarcopenia rather than diagnosing sarcopenia in individual patients. The use of the term is intended to highlight the relevance of muscle mass assessment in understanding the health implications for T2DM patients. Future studies could benefit from a more precise definition and direct assessment of sarcopenia to align with the clinical diagnosis criteria (Cruz-Jentoft et al., 2010; Mesinovic et al., 2019).
Comment 3: Comparing T2DM patients on insulin and OAD may not be appropriate, since the difference in treatment is probably due to the severity of the disease. It also implies that insulin patients were probably better self-monitored and more involved in the treatment of diabetes. A better design would be to study the same person before and after starting insulin treatment.
Response: Your concern regarding the comparison between insulin and oral antidiabetic drug (OAD) treatments is well noted. The distinction in treatment types could indeed reflect differences in disease severity and patient engagement in their diabetes management. To address this, a more robust study design could involve a longitudinal approach where patients are evaluated before and after the initiation of insulin therapy. This method would provide a clearer understanding of insulin's direct impact on muscle mass by accounting for baseline differences and allowing each patient to serve as their own control (Tanaka et al., 2015; Bouchi et al., 2017).
Comment 4: Do the authors have any data about the physical activity of the patients in both groups?
Response: Unfortunately, the current study did not collect detailed data on the physical activity levels of patients in either group. Physical activity is a crucial factor that significantly influences muscle mass and overall physical health. Recognizing its importance, future research should incorporate physical activity assessments, potentially through validated questionnaires or wearable activity monitors, to better understand its role in muscle preservation among T2DM patients (Jung et al., 2020). Including such data would enhance the study's ability to control for this variable and provide a more comprehensive analysis of factors affecting muscle mass.
Comment 5: How did the authors verify that the control patients did not have diabetes or pre-diabetes?
Response: Control patients were carefully verified to ensure they did not have diabetes or pre-diabetes. This verification was accomplished through a thorough review of their medical records, which included fasting plasma glucose levels and HbA1c measurements. These laboratory results were scrutinized to confirm that control participants did not meet the diagnostic criteria for diabetes or pre-diabetes (Nowotny et al., 2015; Park, 2007). This meticulous screening process was essential to establish a reliable comparison group for the study.
Comment 6: Did any of the patients suffer from osteopenia or other complications of diabetes?
Response: The study did not specifically screen for osteopenia or other diabetes-related complications such as neuropathy or retinopathy. However, it is acknowledged that the presence of such conditions could potentially influence muscle mass and overall health status. Including data on these conditions in future studies would provide a more holistic understanding of the patients' health profiles and allow for a more nuanced analysis of how these factors interact with sarcopenia and diabetes management (Sugimoto et al., 2021; Hawkins et al., 2018).
Comment 7: The study's ethical permit number is missing.
Response: The ethical permit number is included within the manuscript.
Reviewer 3 Report
Comments and Suggestions for AuthorsDear,
please find my comments attached.
Kind regards
Comments for author File: Comments.pdf
Author Response
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.
Comment 1: Within chapter 2. Materials and Methods, 2.1 Participants (L73-77), the authors state that individuals with organ failure (n=17), users of any drug that alters body composition (n=3), individuals with a body mass index (BMI) greater than 35 (n=12) or less than 18 (n=3) kg/m², and users of illegal drugs or hormonal or nutritional supplements (n=4) were excluded from the study. Patients with psoas asymmetry (n=6) due to scoliosis or other reasons were also excluded. This confuses the reader, who cannot conclude whether the mentioned participants were excluded from the experimental sample of N=107 before or after the application of the exclusion criteria. It is also necessary to emphasize that the control subsample participants were healthy peers;
Response: Thank you for your observation regarding the exclusion criteria described in Chapter 2, Materials and Methods, section 2.1 Participants (L73-77). To clarify, the mentioned participants were excluded from the initial pool before determining the final experimental sample size of N=107. We will revise this section to clearly state that these exclusions were applied prior to arriving at the final number of participants. Additionally, we will emphasize that the control subsample participants were healthy peers to ensure clear understanding.
Comment 2: The first paragraph of chapter 3. Results (L126-129) needs to be moved to chapter 2. Materials and Methods.
Response: We appreciate your suggestion to move the first paragraph of Chapter 3, Results (L126-129), to Chapter 2, Materials and Methods. This change will enhance the logical flow of the manuscript. We will make the necessary adjustment to place this paragraph in the appropriate section.
Comment 3: The paper lacks a Conclusion chapter, as well as an Institutional Review Board Statement.
Response: We have added a Conclusion chapter to summarize our findings and implications. Additionally, an Institutional Review Board Statement has been included to ensure ethical compliance.
