Memory and executive functions in persons with type 2 diabetes: a meta-analysis

Area of Science:

• Neuroscience
• Endocrinology
• Gerontology

Background:

• Type 2 diabetes mellitus (T2DM) is increasingly linked to cognitive impairment and dementia risk.
• Specific cognitive domains affected by T2DM, such as memory and executive functions, show varied results in existing literature.

Purpose of the Study:

• To systematically review and meta-analyze the influence of T2DM on specific cognitive sub-domains in individuals aged 50 and older.
• To identify which cognitive sub-domains are most affected by T2DM to explain variations in previous research.

Main Methods:

• A comprehensive search of multiple databases (PubMed, ScienceDirect, etc.) was conducted for studies on T2DM and cognition in older adults.
• 15 articles were selected for quantitative analysis, extracting data on memory, executive functions, and processing speed.
• Effect sizes (Cohen's d) were calculated for various cognitive sub-domains.

Main Results:

• T2DM was associated with significant decrements in episodic memory (d=-0.51) and cognitive flexibility (d=0.52).
• Trends towards decrements were observed in logical memory (d=-0.24), phonemic fluency (d=-0.35), and processing speed (d=-0.22).
• No significant differences were found in verbal short-term memory or working memory sub-domains.

Conclusions:

• T2DM detrimentally affects specific cognitive sub-domains, including episodic memory and cognitive flexibility.
• These cognitive deficits associated with T2DM may increase vulnerability to dementia.
• Further research into T2DM's precise impact on cognitive function is warranted.