The Impact of Sleep Deprivation on Hunger-Related Hormones: A Meta-Analysis and Systematic Review

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear corresponding Author, thanks for your submission. I read it with interest and I positively evaluate it. I just want to underline that the way how you cited the references in the text do not meet the journal guidelines.

Author Response

Thank you for your review, we will correct the format of the references.

Reviewer 2 Report

Comments and Suggestions for Authors

This meta-analysis approached an investigation of impact of sleep deprivation on ghrelin and leptin, synthesizing data from six randomized controlled trials published between 2013 and 2023. It revealed high heterogeneity in the ghrelin data and limited sample size across the included studies, which preclude conclusiveness and necessitates more robust, standardized research.

However, the following essential clarifications must be addressed before considering a recommendation for this review:

“Figure 4.1. Forest plot of the effects of sleep deprivation on ghrelin levels” shows opposite changes in ghrelin at SR between Broussard, 2016, Van Egmond, 2022 (significant decrease is depicted for both studies), while significant increase is depicted for Depner, 2021. However, in original paper Broussard et al, 2016 reports “Ghrelin levels were increased after sleep restriction as compared to normal sleep (p<0.01), ‘Van Egmond et al., 2023 et al. reports “After sleep deprivation …ghrelin and adiponectin were higher (839.4 [77.5] vs. 741.4 [63.2] pg/mL and 7.5 [0.6] vs. 6.8 [0.6] μg/mL, respectively; all p < 0.05)”, and Depner et al., 2021 at Figure 4E depicts numerically higher mean ghrelin in SR (sleep restriction) vs CON (controls). This means that all three papers do not have principal discrepancies in changes of ghrelin during sleep restriction.

Notably, Depner et al., 2021 assessed changes in ghrelin continuously during 24 hours at different study segments. Van Egmond et al., 2023 assessed “fasting leptin”, while Broussard et al, 2016 changes in ghrelin continuously during 24 hours, considering both fasting and after meal values.

Obviously there is a discrepancy between Figure 4.1 and Table 4.3. However, Tables’ headings are blackened and are not readable.

The authors should clarify these discrepancies and also provide more details on exactly what portion of the data from Van Egmond et al., 2023 et al. was used, as results differ among study segments and by time of day.

Also, paper “Effects of acute sleep loss on leptin, ghrelin, and adiponectin in adults with healthy weight and obesity: A laboratory study ” is referred as Van Egmond et al., 2022 in the text, but it actually is published in 2023 as indicted in reference list. The authors should be consistent.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

please accpt the suggestions.

Best

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have addressed all comments adequately. I have no further questions and recommend acceptance.

Author Response

Thank you.

Reviewer 3 Report

Comments and Suggestions for Authors

The comments in the annex

Comments for author File: Comments.pdf

Author Response

Regarding the introduction and the previous recommendation, you have supported the content with an inappropriate study. I reiterate the invitation to support the text with references more appropriate to the topic "Sleep Quality and Glycemic Control in Type 1 Diabetes"; in particular, there is a very recent study published on March 14 in a prestigious international journal.

Thank you for this recommendation. The citation has been updated with your recommendation.

The PRISMA Flow Chart is still not compliant with the declared framework, both in terms of graphics and methodology (the individual elements for each selection database are still missing). This issue also affects the description of the results.

The PRISMA flow chart has been updated.

Furthermore, the use of all-uppercase for the title is discouraged.

The title has been updated.

Author Response File: Author Response.pdf