Is Oral Function Associated with the Development of Sarcopenic Obesity and Sarcopenia in Older Adults? A Prospective Cohort Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for the opportunity to review the very interesting work entitled: Is Oral Function Associated with the Development of  Sarcopenic Obesity and Sarcopenia in Older Adults? A  Prospective Cohort Study by Sho Shirotori, Yoko Hasegawa, Koutatsu Nagai, Hiroshi Kusunoki, Shogo Yoshimura, Kana Tokumoto, Hirokazu Hattori, Kayoko Tamaki, Kazuhiro Hori, Hiromitsu Kishimoto and Ken Shinmura

The Authors have presented a very interesting paper for publication based on several years of research on seniors. I consider the topic to be very important. Searching for risk factors for the development of disorders that worsen the quality of life and health of older people can help establish intervention protocols appropriately tailored to the situation.

Although the paper is limited to one area of ​​Japan, and the number of people with sarcopenic obesity in the study group was small, the observations obtained indicate the justification for further research in this area.

The paper was prepared very carefully. All elements were described clearly.

While reading the paper, I noticed minor errors that required checking/correction/taking into consideration.

• Lines 386-387 Maintaining adequate nutrition could cause further muscle loss and metabolic abnormalities - please check the correctness of the sentence
• Below table 1 - lines 232-238 the authors repeated the text from the Diagnosis of Sarcopenic Obesity section (lines 132-152) - maybe it is enough to refer to this section?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In their prospective cohort study, the authors investigated whether oral function is associated with the development of sarcopenic obesity in older adults. Their findings suggest that reduced tongue pressure is significantly associated with an increased risk of developing sarcopenic obesity, independent of other variables related to sarcopenia and obesity. While the manuscript is generally well-written, I do have several concerns that I recommend the authors address to further strengthen the work.

1. The abstract would be stronger if it included specific numbers for key findings. While it mentions that "reduced tongue pressure was significantly associated with an increased risk of sarcopenic obesity," it doesn’t provide the hazard ratio or confidence interval, which would enhance the clarity and precision of the reported results.
2. In the introduction, the authors discuss the "vicious cycle of cross-talk between adipose and muscle tissue" and inflammatory processes. To enhance this section, consider citing “Phenotypes of sarcopenic obesity: exploring the effects on peri-muscular fat, the obesity paradox, hormone-related responses, and the clinical implications” by Alalwan (2020), as it specifically explores peri-muscular fat and its role in different phenotypes. Additionally, this reference provides a more in-depth explanation of hormone-related responses across phenotypes, which could strengthen the mechanistic understanding of inflammatory adipokine secretion and cytokine effects discussed in the paper.
3. The sample size of 597 participants is generally sufficient, but the number of participants with sarcopenic obesity (only 10 at baseline) is quite low, which could limit the statistical power of the findings.
4. The authors should appropriately address the potential confounding factors that might influence both oral function and sarcopenic obesity (e.g., nutritional intake, medication use, exercise, etc.).
5. Please elaborate on why tongue pressure specifically might be a critical factor in sarcopenic obesity, as opposed to other oral function measures.
6. Please justify the minimum two-year follow-up period - is this sufficient to observe meaningful changes in sarcopenic obesity status?
7. In their results, the authors should discuss the surprisingly high improvement rate among participants with sarcopenic obesity (60% were reclassified as obese). It would be helpful to explore what might explain this unexpected finding.
8. The significantly higher risk for males developing sarcopenic obesity (HR = 20.191) should be explained by exploring potential biological or behavioral factors. It would be valuable to consider what underlying mechanisms, such as hormonal differences or lifestyle factors, might contribute to this increased risk in males.
9. Please consider discussing whether tongue pressure measurements could be included in routine geriatric assessments as a potential screening tool.
10. A major oversight in this study is the lack of attention to dietary patterns, which likely play a crucial role in connecting oral function and body composition changes. The authors should acknowledge this limitation and suggest that future studies incorporate comprehensive dietary assessment through food frequency questionnaires, dietary recalls, or nutritional biomarkers to better understand the complex relationship between oral function, diet, and sarcopenic obesity development.
11. Given the small number of sarcopenic obesity cases, the authors should address potential limitations of their statistical approach and the risk of false positives/negatives.
12. Given Japan's unique dietary patterns and lifestyle factors, the authors should discuss whether these findings might translate to Western populations or other Asian countries.
13. In table 1, the asterisks indicating significant differences are present, but the p-value thresholds aren't clearly defined in the table footnote.
14. Table 1 uses standard errors rather than standard deviations. While this is a valid choice, SDs might be more appropriate for describing the sample, while SEs are better for inferential statistics.
15. The structure of Table 2 makes it difficult to compare baseline and follow-up measurements within the same group.
16. The percentages are presented in table 3 without confidence intervals, which would be useful given the small sample sizes in some categories.
17. The authors should strengthen their conclusion by incorporating specific statistical findings and offering clear clinical recommendations for tongue pressure assessment and intervention. It would also be helpful to outline specific directions for future research, including intervention studies, and emphasize the importance of integrating oral health into geriatric care frameworks.
18. While the reference list appropriately cites foundational papers on sarcopenia and obesity diagnostic criteria, it would be significantly strengthened by incorporating more high-quality systematic reviews and meta-analyses that synthesize the current evidence on sarcopenic obesity prevalence, risk factors, and outcomes across diverse populations.

Comments on the Quality of English Language

Careful re-reading by the authors is recommended to take care of the minor editorial blemishes including grammar, punctuation, and improvement of overall readability.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

It is an interesting paper, but there are some points that need to be clarified. 

• The authors described that the participants were analysed twice at a minimum interval of two years. If there are patients suffering from an illness, it is mandatory to send them there to receive adequate treatment. Therefore, the paper should show the results of sarcopenic treatment. 

• In Section 4.3. Clinical implications. The authors write our findings suggest that promoting balanced nutritional intake… but there is no nutritional promotion. 

• Also, the authors conclude that: sarcopenia and obesity appeared to be strongly associated with oral health. All the oral parameters obtained only suggest oral muscular involvement and number of teeth. Oral health evaluation should include mainly periodontal exploration. In severe periodontitis, there may be some mobile teeth with a severe reduction in masticatory capacity. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Now it can be accepted