Age-Related Characteristics of Diastolic Dysfunction in Type 2 Diabetes Patients

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Grigorescu et al. conducted a secondary analysis of cross-sectional and follow-up data to explore predictive factors for left ventricular diastolic dysfunction (LVDD) in a cohort of 138 outpatients with type 2 diabetes mellitus (T2DM). While the study addresses an important clinical issue, I have several concerns regarding the scientific rigor, clarity of methodology, and robustness of the findings.

1. Inconsistency Between Abstract and Results

There appears to be a discrepancy in the descriptive statistics (e.g., participant age) reported in the abstract versus the main results section. This inconsistency should be addressed to ensure accuracy and clarity. The authors should clarify which figures are correct and revise accordingly to maintain internal consistency.

2. Sample Size and Stratified Analyses

Given the modest sample size (n = 138), further stratification of results by age groups raises concerns about statistical power and the reliability of p-values. The rationale for stratifying such a limited sample should be justified more clearly, and the authors should acknowledge the increased risk of type I and type II errors due to small subgroup sizes.

3. Multivariable Model Transparency

In the multivariable analysis for risk factor identification, it is unclear which covariates—beyond age—were included in the model. The current description of the modeling process is insufficient for replication. A clear explanation of variable selection criteria (e.g., based on univariate analysis, clinical relevance, or stepwise selection) and a list of included predictors should be provided to enhance methodological transparency.

4. Statistical Methods for Repeated Measures

If both baseline and 1-year follow-up data were available, as implied, then the repeated-measures nature of the data should be considered in the analysis. For instance, some p-values reported in Table 2 appear to assume independent samples, which may not be appropriate. The authors should revise the analytical approach to account for within-subject correlations (e.g., using paired tests or mixed-effects models) and ensure that the interpretation of longitudinal changes is statistically valid.

5. Limitations and Bias

The manuscript would benefit from a more thorough discussion of limitations. Specifically, potential sources of bias (e.g., selection bias, measurement error, confounding) should be acknowledged. Additionally, the authors should comment on the limited generalizability of the findings due to sample size, design constraints, and potential unmeasured confounders.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

I reviewed with interest the manuscript by Elena-Daniela Grigorescu et al. "Age-Related Characteristics of Diastolic Dysfunction in Type 2 Diabetes Patients". In this article, the authors analyzed the presence of diastolic dysfunction in patients with diabetes mellitus over time - at baseline and one year later. As a result, the authors conclude that asymptomatic diastolic dysfunction of the left ventricle is common in patients with type 2 diabetes without atherosclerotic manifestations, and age is a significant risk factor for diastolic dysfunction. These observations may probably be of practical interest, but during the review I had the following questions and comments: 1. First of all, I have doubts about the novelty of the results obtained by the authors. Indeed, the authors' statements in the conclusion: "Asymptomatic left ventricular diastolic dysfunction is common in type 2 diabetes patients without atherosclerotic manifestations. Age is a significant risk factor for diastolic dysfunction" (lines 517-519) are well-known data, repeatedly published earlier. For which the authors conducted another study. 2. Interestingly, in some patients, the diastolic function of the left ventricle worsened after a year, while in others it increased. The authors do not analyze this fact in any way, although it is very interesting and in the future may help in finding ways to correct diastolic dysfunction in these patients. The authors only indicate that "No significant differences were found in the 52-week data between patients with worsened and those with stable or improved diastolic function" (lines 268-269); and repeat the same in the discussion ("In our study, a comparative analysis between patients with worsened and those with stable or improved diastolic function showed no significant differences after 52 weeks" - lines 487-489). I believe that the data from these groups should have been presented in full, including information on the therapy received. What is the reason for such different dynamics? This was more interesting for readers than information on the dynamics of the state of diastolic dysfunction of the LV in different age groups.

3. In Table 12, some of the echocardiography indicators do not have units of measurement.
4. Figure 1 is unclear, it needs to be corrected.
5. The text contains a lot of digital information, which is difficult for the reader to digest. Thus, the data of the correlation analysis should be presented in a table.
6. In addition, it is unclear why the authors decided to present such information as "The crosstabulation test revealed that more females had grade 1 LVDD than males (p = 0.04)" - lines 230-231. Why was the influence of gender assessed only for this indicator? It is unclear.
7. The authors note: "The multivariate logistic regression analysis identified age over 65 as an independent risk factor for diastolic dysfunction (Exp B = 9.85, 95% CI = 1.29–75.36, p = 0.027)" - lines 232-233. In general, this is a completely expected fact, but the question is different - what indicators were included in the logistic regression model? Why is this analysis not mentioned in section 2.4. Statistical analyses?

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I’d personally suggest the authors double-check for consistency across their abstract, results, and discussion. Some interpretations don’t seem fully supported by the data.

It may also help if they clarify their rationale with more focus on age-related mechanisms from a hypothesis-driven perspective, rather than a purely data-driven one, which the current analysis doesn’t fully support.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The authors responded to my comments and made corrections to the text of the manuscript. I have no other comments.

Author Response

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Author Response File: Author Response.docx