Public Health

Area of Science:

• Neuroscience
• Metabolic Health
• Public Health

Background:

• Lipids are crucial for brain function.
• Black Americans face higher rates of midlife metabolic disorders and dementia.
• This study investigates early hyperlipidemia and its link to late-life cognition in an all-Black cohort.

Purpose of the Study:

• To assess the relationship between early adulthood hyperlipidemia and late-life cognitive function.
• To explore the mediating role of midlife metabolic disorders in this association.

Main Methods:

• Included 773 Black participants from California-based aging studies.
• Hyperlipidemia (total cholesterol ≥ 200 mg/dL) measured in early adulthood (ages 25-40).
• Midlife metabolic disorders (dyslipidemia, diabetes, hypertension) identified via electronic health records (ages 40-65).
• Late-life cognition (executive function, verbal episodic memory, semantic memory) assessed (ages 50+).
• Linear regression and causal mediation analyses were employed.

Main Results:

• Early adulthood hyperlipidemia was associated with significantly worse verbal episodic memory.
• Associations with executive function and semantic memory were non-significant but in a worse direction.
• Midlife dyslipidemia and diabetes partially mediated the link between early hyperlipidemia and executive function/semantic memory.
• Midlife diabetes partially mediated the association with verbal episodic memory.

Conclusions:

• Early hyperlipidemia may impact late-life executive function and semantic memory through vascular pathways involving midlife dyslipidemia and diabetes.
• Non-vascular mechanisms may link early hyperlipidemia to poorer late-life verbal episodic memory and warrant further investigation.