Aging, Diabetes, Obesity, and Cognitive Decline: A Population-Based Study.

Area of Science:

• Gerontology
• Metabolic Syndrome
• Neuroscience

Background:

• Diabetes and obesity are established risk factors for cognitive decline in older adults.
• The precise mechanisms linking these conditions to cognitive impairment remain incompletely understood.
• Investigating these mechanisms is crucial for developing targeted interventions.

Purpose of the Study:

• To explore the relationship between metabolic and inflammatory markers and cognitive decline in a population-based cohort of older adults.
• To identify specific predictors of cognitive decline associated with diabetes, obesity, and central obesity.

Main Methods:

• A 10-year population-based cohort study involving 478 individuals aged 65 and older.
• Assayed fasting blood for markers of glycemia (HbA1c), insulin resistance, obesity (adiponectin), and inflammation (C-reactive protein).
• Used multivariable regression and machine learning (Classification and Regression Tree) to model predictors of cognitive decline, adjusting for confounding factors and stratifying by waist-hip ratio (WHR).

Main Results:

• Hemoglobin A1c (HbA1c) was significantly associated with cognitive decline in the overall sample.
• This association persisted in individuals with higher waist-hip ratio (WHR), indicating central obesity.
• In participants with lower WHR, adiponectin levels were associated with faster cognitive decline, suggesting a novel risk factor.

Conclusions:

• Modest hyperglycemia may independently contribute to faster cognitive decline in older adults with central obesity.
• Adiponectin emerges as a potential independent risk factor for cognitive decline in older adults without central obesity.
• These findings highlight distinct metabolic pathways influencing cognitive aging based on body fat distribution.