Review History


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Summary

  • The initial submission of this article was received on February 13th, 2015 and was peer-reviewed by 2 reviewers and the Academic Editor.
  • The Academic Editor made their initial decision on March 18th, 2015.
  • The first revision was submitted on March 26th, 2015 and was reviewed by 2 reviewers and the Academic Editor.
  • A further revision was submitted on April 10th, 2015 and was reviewed by the Academic Editor.
  • The article was Accepted by the Academic Editor on April 16th, 2015.

Version 0.3 (accepted)

· · Academic Editor

Accept

The authors satisfactorily revised their manuscript.

Version 0.2

· · Academic Editor

Minor Revisions

The authors need to take into account the reviewer's comments and if not please describe the rebuttal.

Reviewer 1 ·

Basic reporting

The manuscript has been revised.

Experimental design

The manuscript has been revised.

Validity of the findings

The manuscript has been revised.

Comments for the author

The authors responded to majority of my concerns.

Reviewer 2 ·

Basic reporting

No comments

Experimental design

No comments

Validity of the findings

The negative association between L/W and weight is a mathematical consequence of the formula. Please avoid this analysis and related comments.
The data should be made available in a repository.

Comments for the author

The paper is improved and the authors have revised the article according to suggestions. The analysis with sexes separated and accounting for the effect of age has strengthened the results. However, some revision is still needed.

Background
Line 62: “Obesity due to sarcopenia”; please change the sentence, that improperly suggests a causal relationship between sarcopenia and obesity.
Line 50: The added sentence “We should also treat obesity considering the age of patients.” is too general. Please add a comment considering body composition variations in ageing (see for example, Buffa et al., Coll Antrop, 2011).

Methods
Lines 91-97 "Anthropometric measurements": the mentioned references are not appropriate to describe anthropometric measurements. Please mention a manual such as the one published by Lohman et al. (1988) or Weiner and Lourie (1981).
Lohman TG, Roche AF, Martorell R. Anthropometric Standardization Reference Manual. Human Kinetics, 1988.
Weiner JS and Lourie JA. Practical human biology. Academic Press, 1981

Results
The results are too detailed and sometimes redundant with tables.
Line 196 "These results are summarized in Table 3". It is not clear if the results summarized in table 3 are those adjusted for age.
Line 203 "These results are showed in Table 4". Please specify if the results of table 4 are adjusted for age or not.

Discussion
Line 223 “no significant correlations between L/W and L/U ratios were observed” should be “ no significant correlations between L/W or L/U ratios and age were observed”.
Line 240 “After adjustment for age, favorable associations of L/W and L/U ratios with metabolic parameters remained” should be “After adjustment for age, associations of L/W and L/U ratios with favorable metabolic values remained”.
Line 280 “... by Stensvold et al. warrants ...” should be “... by Stensvold et al. (2010) warrants ...“

Line 302-305 “Women were older [...] and metabolic parameters”; please modify or delete this sentence which is not based on the results of the paper.

References
References should be mentioned without the first letter of name within the text (Matsushita Y et al., 2010; Nordhamn K et al., 2000; Faria SL et al., 2014; Misra A et al.; Messier V et al, 2011). At the end of the paper they should be listed in an alphabetical order.

Tables
In my opinion Table 1 is unnecessary and should be eliminated. Information not shown in table 2 (es. smoking status, treatment) should be included within the text.

Version 0.1 (original submission)

· · Academic Editor

Major Revisions

The authors need to carefully address the issues raised by the reviewers. Particularly they need to re-analyze their data because of the small sample size and the heterogeneity.

Reviewer 1 ·

Basic reporting

Their data has somehow clinical significance. However, the scientific validity and their suitability is not enough to publish in the present form. Please see my comments for the authors.

Experimental design

The sample size is too small and their data should be adjusted by sex and age.

Validity of the findings

I can not agree with the results about relationship between visceral fat mass and L/W ratio. The authors have to reanalyze the data carefully.

Comments for the author

The authors showed that lower extremity muscle mass-to-body weight ratio is related to metabolic parameters in patients with obese type 2 DM.

Since sarcopenia is a critical health problem in not only elderly subjects but also patients with obese type 2 DM, preservation of muscle mass against aging or development of obesity is important issue in clinical practice.

However, the present study has several problem to clarify the relationship between the muscle mass and metabolic disorders.

1. In the present study, the authors included male and female individuals in a wide age range. Since it has been well known that gender and aging influence differences in adipose tissue distribution, muscle mass and strength, the authors have to adjust the data by sex and age.
2. Not only L/W ratio but also upper extremity muscle mass-to-body weight ratio should be analyzed.
3. Why did only visceral fat area have no association with L/W ratio and L/U ratio? Several comments are needed in the discussion section.
4. As the authors mentioned in the limitations, the sample size is too small for the reproducible analysis.
5. The authors had 148 patients with type DM during the study period. Didn’t the authors analyze the clinical data in the subjects with BMI 25-29 ranged as well as over 30 group?
6. Since cigarette smoking has been known to influence body weight and skeletal muscle strength, smoking status should be revealed in the characteristics of the patients.

Reviewer 2 ·

Basic reporting

Authors provide ethical statement and they do not declare any competing interest.
Acknowledgements are not included.
Figures 1 and 2 are not very useful (see general comments).

Experimental design

Please see general comments

Validity of the findings

Please see general comments

Comments for the author

General comments

The Authors analyze a sample of 26 male and female patients with type 2 diabetes and obesity, aged 27 to 76 years. Two indices of sarcopenia (L/W ratio: lower extremity muscle mass to body weight; L/U ratio: lower extremity to upper extremity muscle mass) are considered in relation to a wide range of variables, related to anthropometry and body composition, serum lipid profile, and physical activity measurements.
The results of the paper are interesting and potentially relevant. However, several points make this article unsuitable for publication in the present form.

My major concern regards the small size and the heterogeneity of the sample, in terms of gender, age and medical therapy (the last factor being mentioned among limitations). Gender and age can interfere with the results - but are not accounted for in the analyses -, being related to anthropometry and body composition differences. In order to strengthen the analysis, I suggest to verify if groups with different BMI are characterized by sex or age differences. In case of a significant difference, the between-group analysis should be eliminated, or performed with sexes separated and taking into account the possible effect of age.

Another important point is related to the description and interpretation of results. I don't see a great difference between the results obtained with L/W and L/U ratios that can justify the conclusion that the lower extremity is especially important “to prevent sarcopenic obesity and lower associated risks for metabolic syndrome and early mortality”. Moreover, I suggest to avoid assertions on possible causal relationships, such as “A significant and negative correlation [...] type 2 diabetes patients” (lines 180-182) or “Moreover, higher […] to increase HDL-C levels” (lines 189-192). In fact, as the same authors state in the limitations section, “the cross-sectional study design does not allow causal relationships to be deduced”.


Detailed comments
Abstract
Methods should include physical activity measurements and results should be more comprehensive.

Background
Lines 23-24: Recommendations to treat obesity should be discussed also considering the age of patients.

Methods
Lines 54-59 (Anthropometric measurements): Please give a reference to the technique.
Lines 61-68 (Body composition analysis): Please mention what equation have been used to evaluate fat mass. Maybe, the recent papers on bioimpedance analysis in patients with type 2 diabetes could fournish some comparative data (Buffa et al., Nutrition, 2013; Dittmar et al., Diabetic Medicine, 2014).
Lines 89-115 (Physical activity measurements): This paragraph is explained with a greater details than the previous ones. Please homogenize.
Lines 117-123 (Statistical analysis): For comparing differences in the L/W and L/U ratios between the higher and lower BMI groups a parametric test, such as the Student't, should be used.

Results
Please consider the above general comments.
Lines 132-133: Please substitute L/W ratio with L/U ratio.

Discussion
Line 191: Please add the year to “Stensvold et al .”

Limitations
Please include among limitations that “PAL was measured during a period of hospitalization and so these findings may not represent the true physical activity of subjects in daily life outside the hospital.” (line 170)

Tables and figures
Table 1: Please show the results with sexes separated.
Figures 1 and 2 are not very useful (see general comments). I suggest to eliminate them and add a table showing the results of the comparison between groups with different BMI.

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