Overall, excellent written paper that evaluates an important and interesting topic within the field of diabetes literature.

There were just a few areas where greater information would be beneficial.

Regarding your search methodology, could the authors please clarify who they mean by we? Was only one author responsible for this? Did multiple authors participate in the search?

Was there any verification process in which more than one author reviewed the searches (typically a minimum of two review to minimize bias).

The authors appear to not have considered any grey literature in their search (e.g. preprints that have not been peer reviewed yet). Can the authors explain why they took this approach?

There has been an explosion of preprint literature made available with COVID-19, and typically rigorous reviews consider grey literature as there can be considerable barriers to publication.

The authors did a great job attempting to address several areas for growth in a short amount of time, including conducting a complete systematic literature review and meta-analysis.

The biggest concerns I have for the paper are two-fold:

(1) There is an exceedingly high level of heterogeneity suggesting that it is inappropriate to conduct a meta-analysis, yet no attempt to address such a high I2 value was undertaken.

Subset analyses should be undertaken, or a median and IQR value should be reporter rather than the meta-analysis value. Sub-analyses I would recommend include:

(A) Separate based on country of origin

(B) Exclude those with missing information on sex.

(2) It is unclear why a systematic literature review and meta-analysis was included for what was submitted as a letter to the editorial. Typically, papers of this level of rigour are considered as original research articles.