Polymorphism in Adiponectin and Adiponectin Receptor Genes in Diabetes Mellitus Pathogenesis

Round 1

Reviewer 1 Report

 

The authors examined the association between adiponectin and adiponectin receptor gene polymorphisms and diabetes type 2.

Comments:

The introduction should provide a direct explanation of how the investigated SNPs and adiponectin are associated with diabetes type 2. The information about the functional role of studied polymorphism is needed.

Patient recruiting and randomization are not explained. How the patients were selected? 

Please calculate statistical power of this study.

The authors should discuss the potential clinical significance of the results obtained.

 

Limitations of the study should be discussed.

 

Author Response

Based on respected reviewers’ comments, we have made the number of changes accompanying them with the remarks below:

1. An explanation of how the investigated SNPs and adiponectin are associated with
diabetes type 2 was directly provided in the introduction by putting Line 124-138
discussing the rationale of selection of polymorphic ADIPOQ gene rs2241766
/rs1501299, ADIPOR1 gene rs2275737/rs2275738, ADIPOR2 genes
rs11061971/rs16928751 in the diabetes mellitus pathogenesis in the Introduction, from
the Materials and Methods (as was proposed by Reviewer 3)
2. The authors added the information how/whether this study was approved by an ethical
committee, in the Materials and Methods, Patient Selection (although the named
information was previously given in Institutional Review Board Statement and
Informed Consent Statement according to Template).
3. Patient recruiting and randomization were explained; also summarizing the baseline
characteristics of the cohort in a table 1 was added
4. In the statistical analysis ‘The Mann-Whitney test was applied to assess the 168 statistical
significances of differences between patient groups’, the values that are compared were
specified.
5. line 44: removed “poor”, as mentioned by Reviewer 2
6. Line 227 to 232 describing the patient characteristics and laboratory parameters was
putted before discussing the polymorphism.
7. Reviewer 3 inquired where the index for the DM2 patients is in table 2. If mentioned
BMI, it was given accordingly to studied polymorphisms that corresponds to the aim of
the study (It is table 3 in corrected variant).
8. Sufficient discussion on the table 2 was added(It is table 3 in corrected variant).
Particularly, information about relations of blood glucose concentration, HbA1c and
BMI’s with appropriate SNP’s was completed broader. In addition, in line 240-242,
position “A relationship was also found between the GA (rs16928751) genotype of the
ADIPOR2 241 gene and the BMI index’ was described in greater extend.
9. The following information “rs16928751 polymorphism of the ADIPOR2 gene was 314
associated with an increased risk of DM2 in the Russian population’ ‘the TG rs2275737
genotype was 323 related to high levels of HbA1c and the TT rs2275738 genotype to
hyperglycemia” was cited from [30] of our References. The named research used
Calculator for statistics in case—control studies (http://gen-exp.ru/calculator_or.php)
which do not mention generation of the correlation plots (Spearman’s correlation). We
used the odds ratio criterion (OR) and 95% confidence interval (95% CI) for the
determination of SNP’s association with DM2. We insist on the fact that Spearman’s
correlation does not bring useful information for our type of study.
10. combinatorial analyses of genotypes (lines 210-226) was illustrated by scheme (Figure 1)
and were supplemented by a “conclusion” statements
11. Statistical significance between the DM2 group and controls was added
12. The authors discussed the potential clinical significance of the results obtained in
Discussion and Conclusion.
13. From line 243, part 4, Discussion is separated
14. Corrections according to lines 4, 6 of Reviewer 3 were completed.
15. Limitation of the study was described after Conclucion part
16. All the changes were highlighted in the text of the manuscript.

Reviewer 2 Report

The authors investigate the prevalence of SNPs associated with type 2 diabetes mellitus (DM2) in a sample of ~100 individuals affected with DM2 and ~100 individuals with no history of DM2 or related factors. The investigation was done for three genes involved in the adiponectin-mediated pathway, which is associated to DM2-related factors. The authors found some statistically significant associations between specific genotypes at the SNPs analysed and the risk of DM2, and discussed this in the light of previous literature.

 

The study is well explained, the results are clear and discussed in a fair manner. The authors should, however, make it clear how/whether this study was approved by an ethical committee, and/or how the consents were managed and dealt with, and whose responsibility they are.

 

Otherwise, I have no significant points to raise and leave some suggestions:

- line 44: consider removing “poor”, it avoids a “judgement” and the sentence still makes sense

- combinatorial analyses of genotypes (lines 210-226) – they could be illustrated by a table or scheme, for easier readout, and a “conclusion” statement could be added to each of them; are the combinations statistically significantly different between the DM2 group and controls? It is not clear from the text.

- from line 243, it should be section 4. Discussion, if I understand correctly

Author Response

Based on respected reviewers’ comments, we have made the number of changes accompanying them with the remarks below:

1. An explanation of how the investigated SNPs and adiponectin are associated with
diabetes type 2 was directly provided in the introduction by putting Line 124-138
discussing the rationale of selection of polymorphic ADIPOQ gene rs2241766
/rs1501299, ADIPOR1 gene rs2275737/rs2275738, ADIPOR2 genes
rs11061971/rs16928751 in the diabetes mellitus pathogenesis in the Introduction, from
the Materials and Methods (as was proposed by Reviewer 3)
2. The authors added the information how/whether this study was approved by an ethical
committee, in the Materials and Methods, Patient Selection (although the named
information was previously given in Institutional Review Board Statement and
Informed Consent Statement according to Template).
3. Patient recruiting and randomization were explained; also summarizing the baseline
characteristics of the cohort in a table 1 was added
4. In the statistical analysis ‘The Mann-Whitney test was applied to assess the 168 statistical
significances of differences between patient groups’, the values that are compared were
specified.
5. line 44: removed “poor”, as mentioned by Reviewer 2
6. Line 227 to 232 describing the patient characteristics and laboratory parameters was
putted before discussing the polymorphism.
7. Reviewer 3 inquired where the index for the DM2 patients is in table 2. If mentioned
BMI, it was given accordingly to studied polymorphisms that corresponds to the aim of
the study (It is table 3 in corrected variant).
8. Sufficient discussion on the table 2 was added(It is table 3 in corrected variant).
Particularly, information about relations of blood glucose concentration, HbA1c and
BMI’s with appropriate SNP’s was completed broader. In addition, in line 240-242,
position “A relationship was also found between the GA (rs16928751) genotype of the
ADIPOR2 241 gene and the BMI index’ was described in greater extend.
9. The following information “rs16928751 polymorphism of the ADIPOR2 gene was 314
associated with an increased risk of DM2 in the Russian population’ ‘the TG rs2275737
genotype was 323 related to high levels of HbA1c and the TT rs2275738 genotype to
hyperglycemia” was cited from [30] of our References. The named research used
Calculator for statistics in case—control studies (http://gen-exp.ru/calculator_or.php)
which do not mention generation of the correlation plots (Spearman’s correlation). We
used the odds ratio criterion (OR) and 95% confidence interval (95% CI) for the
determination of SNP’s association with DM2. We insist on the fact that Spearman’s
correlation does not bring useful information for our type of study.
10. combinatorial analyses of genotypes (lines 210-226) was illustrated by scheme (Figure 1)
and were supplemented by a “conclusion” statements
11. Statistical significance between the DM2 group and controls was added
12. The authors discussed the potential clinical significance of the results obtained in
Discussion and Conclusion.
13. From line 243, part 4, Discussion is separated
14. Corrections according to lines 4, 6 of Reviewer 3 were completed.
15. Limitation of the study was described after Conclucion part
16. All the changes were highlighted in the text of the manuscript.

Reviewer 3 Report

The present paper discusses the polymorphism in adiponectin and its receptors (ADIPOR1 and ADIPOR2) genes in diabetes mellitus pathogenesis. Overall, this is an interesting paper, but lack of clear results present and sufficient discussion, even miss the subtitles for discussion part. In the results part, the authors do not have any figures, which makes the readers hard to follow all the numbers and always get lost in the names of genes. It is highly recommended to generate correlation plots to highlight the association between the polymorphism genes and DM2 phenotypes.

1. It is recommended to summarize the baseline characteristics of the cohort in a table, such as clinical parameter: age, BMI, gender……, laboratory parameter: HbA1c, plasma glucose level…….
2. Line 124-138 discuss the rationale of selection of polymorphic ADIPOQ gene rs2241766 /rs1501299, ADIPOR1 gene rs2275737/rs2275738, ADIPOR2 genes rs11061971/rs16928751 in the diabetes mellitus pathogenesis. This paragraph should be put in the Introduction, not in the Materials and Methods.
3. For the Patient Selection part, the author need to state that “the protocol was approved by the Ethics Committee of XXX center”
4. Keep aligned with subtitle, eg. 2.2.1 with 2.2.2, 2.2 with 2.3. Also text-indent in 2.6
5. In the statistical analysis: ‘The Mann-Whitney test was applied to assess the 168 statistical significances of differences between patient groups’, please specify the values that are compared.
6. Line 177, ‘which was observed less than in the control group’, deleted ‘than’.
7. Line227 to 232: it is recommended to describe the patient characteristics and laboratory parameters before discuss the polymorphism.
8. In table 2, where is the index for the DM2 patients?
9. The authors did not give sufficient discussion on the table 2. In line 240-242, “A relationship was also found between the GA (rs16928751) genotype of the ADIPOR2 241 gene and the BMI index’. What is the relationship between the two variables?
10. This paper have ‘3. Results’ and ‘5. Conclusions’, but does not include ‘4. Discussion’ part.
11. ‘rs16928751 polymorphism of the ADIPOR2 gene was 314 associated with an increased risk of DM2 in the Russian population’ ‘the TG rs2275737 genotype was 323 related to high levels of HbA1c and the TT rs2275738 genotype to hyperglycemia’ It is recommended to generate the correlation plots (Spearman’s correlation?) to highlight the association between the polymorphism genes and DM2 phenotypes.

 

 

 

Author Response

Based on respected reviewers’ comments, we have made the number of changes accompanying them with the remarks below:

1. An explanation of how the investigated SNPs and adiponectin are associated with
diabetes type 2 was directly provided in the introduction by putting Line 124-138
discussing the rationale of selection of polymorphic ADIPOQ gene rs2241766
/rs1501299, ADIPOR1 gene rs2275737/rs2275738, ADIPOR2 genes
rs11061971/rs16928751 in the diabetes mellitus pathogenesis in the Introduction, from
the Materials and Methods (as was proposed by Reviewer 3)
2. The authors added the information how/whether this study was approved by an ethical
committee, in the Materials and Methods, Patient Selection (although the named
information was previously given in Institutional Review Board Statement and
Informed Consent Statement according to Template).
3. Patient recruiting and randomization were explained; also summarizing the baseline
characteristics of the cohort in a table 1 was added
4. In the statistical analysis ‘The Mann-Whitney test was applied to assess the 168 statistical
significances of differences between patient groups’, the values that are compared were
specified.
5. line 44: removed “poor”, as mentioned by Reviewer 2
6. Line 227 to 232 describing the patient characteristics and laboratory parameters was
putted before discussing the polymorphism.
7. Reviewer 3 inquired where the index for the DM2 patients is in table 2. If mentioned
BMI, it was given accordingly to studied polymorphisms that corresponds to the aim of
the study (It is table 3 in corrected variant).
8. Sufficient discussion on the table 2 was added(It is table 3 in corrected variant).
Particularly, information about relations of blood glucose concentration, HbA1c and
BMI’s with appropriate SNP’s was completed broader. In addition, in line 240-242,
position “A relationship was also found between the GA (rs16928751) genotype of the
ADIPOR2 241 gene and the BMI index’ was described in greater extend.
9. The following information “rs16928751 polymorphism of the ADIPOR2 gene was 314
associated with an increased risk of DM2 in the Russian population’ ‘the TG rs2275737
genotype was 323 related to high levels of HbA1c and the TT rs2275738 genotype to
hyperglycemia” was cited from [30] of our References. The named research used
Calculator for statistics in case—control studies (http://gen-exp.ru/calculator_or.php)
which do not mention generation of the correlation plots (Spearman’s correlation). We
used the odds ratio criterion (OR) and 95% confidence interval (95% CI) for the
determination of SNP’s association with DM2. We insist on the fact that Spearman’s
correlation does not bring useful information for our type of study.
10. combinatorial analyses of genotypes (lines 210-226) was illustrated by scheme (Figure 1)
and were supplemented by a “conclusion” statements
11. Statistical significance between the DM2 group and controls was added
12. The authors discussed the potential clinical significance of the results obtained in
Discussion and Conclusion.
13. From line 243, part 4, Discussion is separated
14. Corrections according to lines 4, 6 of Reviewer 3 were completed.
15. Limitation of the study was described after Conclusion part
16. All the changes were highlighted in the text of the manuscript.

Round 2

Reviewer 1 Report

The revised version of the manuscript is suitable for publication.

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

 

The authors examined the association between adiponectin gene polymorphosms and clinical parameters in patients with diabetes type 2.

 

 

Introduction - the information about the functional role of studied polymorphism is needed.

Inclusion and exclusion criteria should be described more precisely. 

The description of patients is insufficient and should be extended.  

 

The authors should compare the distribution of adiponectin gene polymorphisms in patients with type 2 diabetes with a control group of healthy individuals to examine whether these polymorphisms are associated with risk of type 2 diabetes.

Reviewer 2 Report

Although the study conducted by Shramko et al. has clinical relevance to increase the knowledge about the molecular bases that are associated with type 2 diabetes mellitus pathophysiology, there are many weaknesses in the work developed and the manuscript still does not meet the expectations for publication. 

Reviewer 3 Report

This is a genetic association study in DM2 patients that aims to establish a link between SNPs in adiponectin receptor genes and several clinical characteristics.

The methods are adequately described, and there is a reasonable hypothesis behind the study objectives. However, I think that a genetic association study with just 94 patients is just not valid anymore. In addition, only four SNPs were analyzed, with no explanation on why these and not other variants were selected. Event though the authors report some significant correlations, such as rs1501299 or rs2275738 and glucose concentration or rs2275737 and HbA1c, there is no way that the conclusions drawn from such a small sample size and a set of four SNPs may be consider relevant.

One would think that including non-diabetic subjects in the analysis would give a better idea of the connection between these SNPs and DM2

table 2 lacks p-values for the association analyses