A Life Course Approach to Understanding Cognitive Impairment in Adults with Type 2 Diabetes: A Narrative Literature Review
Round 1
Reviewer 1 Report
This is an important paper summarizing currently available evidence regarding diabetes and the risk of cognitive impairment. Please see the below suggestions
1. In line 87, add age for the beginning of a decline in cognitive functioning instead of just saying late middle adulthood
2. line 89, what are the risk factors for cognitive decline?
3. In line 100, what are the factors associated with cognitive impairment?
4. line 110, says studies but only cite one study
5. Line 236, is it a negative or positive association between education and depression?
6. in figure 2, give the age range for each category
Author Response
Thank you for your insightful comments and we have carefully reviewed your comments and suggestions and made revisions accordingly. I have attached our response to your comments here.
Thank you!
Jie Hu, PhD, RN, FAAN
Author Response File: 
Author Response.docx
Reviewer 2 Report
It needs to be clarified what literature gap the authors aimed to fill with this manuscript. The manuscript needs major English language editing. The terminology used is confusing and requires extensive clarification. In addition, authors use specific terms as a synonym where they should not do so (for example, cardiovascular diseases and hyperlipidemia could not be used as synonyms). Also, the terms such as "middle adults" are not the best word choice. It is not easy to understand how diabetes or cardi-vascular diseases could be termed as "physiological factors"? Some of these factors could be termed "modifiable risk factors of cognitive dysfunction among patients with diabetes mellitus". The manuscript misses to include some of these factors. Among others, proteinuria should be at least mentioned. Also, the major disadvantage of this manuscript is that it does not consider the obesity and obesity-related cofounding effects in cognitive impairment in patients with diabetes mellitus. Also, there is no mention of the sex-specificity of the cognitive impairment.
It is paramount to indicate which type of diabetes the manuscript is dealing with. From my point of view, it is entirely different if the manuscript deals with type 1 or type two diabetes mellitus or gestational diabetes during pregnancies. Also, the one point missing in the manuscript is the paragraph about the differences and/or similarities of cognitive impairment in type 1 and type 2 diabetes mellitus. Moreover, the title of the submitted manuscript could be improved to indicate the type of study presented in the manuscript. This is of importance, given that abstract of the manuscript is formatted in a way that could be misleading. For example, one could think that this manuscript contains a meta-analysis with newly generated data and statistical analysis.
In the discussion, it would be nice to indicate the type of cited studies to illustrate the strength of the presented data. Moreover, the short paragraph related to the pathophysiology of cognitive impairment in diabetes mellitus is missing. Finally, the table that represents the most important studies in the field highlighting the advantages and disadvantages of each study, would be great.
The manuscript needs major English language editing. The terminology used is confusing and requires extensive clarification.
Author Response
Thank you for your insightful comments and we have carefully reviewed your comments and suggestions and made revisions accordingly. I have attached our response to your comments here.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Thank you for addressing my comments as much as possible.
I'd like to point out that minor editing of the English language is required, so please approach this issue carefully during the typesetting of the manuscript.
