Table 1.

Methodology and study selection.

Step	Procedure
Database selection	Four reputable databases, namely PubMed, MEDLINE, Embase, and PsycINFO, were selected for the literature search.
Literature search	A comprehensive search strategy utilizing relevant keywords and Medical Subject Headings (MeSH) terms was meticulously designed and executed. The search was confined to studies published within the 10-yr period leading up to August 2023.
Inclusion criteria	Inclusion criteria embraced a diverse array of research articles, observational studies, and clinical trials that explored the intricate relationship between diabetes and cognitive impairment. Studies addressing various cognitive domains were eligible for consideration.
Exclusion criteria	Exclusion criteria comprised studies that lacked relevance to the nexus of diabetes and cognitive impairment, studies devoid of pertinent outcome measures, and studies not published in the English language.
Initial screening	Titles and abstracts of identified articles were subjected to meticulous review to assess their relevance to the research topic.
Full-text evaluation	Full-text articles that passed the initial screening were subjected to a comprehensive evaluation in accordance with predefined inclusion and exclusion criteria.
Data extraction	Relevant data from the selected studies were meticulously extracted. This included crucial information such as study design, sample size, key findings, and acknowledged limitations.
Narrative synthesis	Given the inherent heterogeneity in study designs, outcomes, and populations across the selected studies, a narrative synthesis approach was thoughtfully employed. This facilitated the summarization of findings, identification of common themes, emerging trends, and any notable disparities.