The relationship between impaired glucose tolerance, type 2 diabetes, and cognitive function

Area of Science:

• Neuroscience
• Endocrinology
• Psychology

Background:

• Type 2 diabetes is increasingly prevalent, with growing evidence linking it to cognitive impairments.
• Cognitive deficits in diabetic patients range from mild impairments to dementia.
• Neuropsychological assessments are crucial for understanding the impact of diabetes on cognition.

Purpose of the Study:

• To review and synthesize findings on cognitive function in treated and untreated type 2 diabetes patients.
• To provide an overview of neuropsychological assessments used in evaluating diabetic cognitive function.
• To identify factors influencing cognitive deficits in type 2 diabetes.

Main Methods:

• Systematic review of published studies on cognitive function in type 2 diabetes.
• Analysis of neuropsychological assessment data from treated and untreated patients.
• Evaluation of the impact of glycemic control and comorbidities on cognitive performance.

Main Results:

• Cognitive deficits are evident in untreated type 2 diabetes, particularly in older adults.
• Improved glycemic control appears to attenuate cognitive deficits.
• Deficits are most common in verbal memory and processing speed; visuospatial, attention, semantic, and language functions are often preserved.
• Factors like depression and vascular disease exacerbate cognitive decline in diabetic patients.

Conclusions:

• Good glycemic control in type 2 diabetes has a minimal impact on cognitive function before age 70.
• Early onset, poor glycemic control, and vascular disease can lead to early cognitive deficits.
• In older adults (70+), diabetes may accelerate cognitive decline by interacting with conditions like Alzheimer's disease and vascular dementia.