Acute Plasma Abeta Responses to Stress

University of Southern California

Status: Completed

Conditions: Stress Reaction; Stress Physiology

Treatments: Behavioral: No-stress; Behavioral: Sympathetic Nervous System Activation

Study type: Interventional

Funder types: Other

Identifiers

NCT05521919

UP-22-00404

Details and patient eligibility

About

Research has shown that activation of the sympathetic nervous system for extended periods or during certain times in life can increase the risk for Alzheimer's disease. Some research in animal models show that acute activation of the sympathetic nervous system through stress exposure can increase certain Alzheimer's disease-related biomarkers, such as amyloid-beta, within hours of exposure. However, how acute sympathetic nervous system activation via stress exposure affects amyloid-beta levels in humans has yet to be examined.

In this study, the investigators will examine whether brief increases in sympathetic activation result in immediate changes in plasma amyloid-beta levels in the five hours after exposure.

Full description

Aim 1: determine whether acute exposure to stress (increasing sympathetic nervous system activation) increases plasma amyloid-beta-40 and amyloid-beta-42 in the five hours following exposure.

Enrollment: 38 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy adult weighing at least 110 pounds
• No chronic conditions or illness
• Taking no medications or drugs that might alter the stress response (e.g., corticosteroids, beta-blockers, and others)
• Not using any hormone-containing medication (e.g., hormonal contraceptives, hormone replacement, etc.)
• No contraindications for cold pressor test exposure (high blood pressure, heart disease, dysrhythmia, peripheral vascular disease, any other cardiovascular disorder, diabetes, vasculitis, lupus, tingling or numbness in the hands and/or feet, cryoglobulinemia, and Reynaud's phenomenon)
• No history of fainting during blood draws
• No phobia of having their blood drawn
• No general history of fainting or seizures
• Not currently diagnosed with a mood disorder (e.g., major depressive disorder)
• Not pregnant in the past 12 months
• Not lactating in the past 12 months
• Not trying to become pregnant if premenopausal
• Experienced natural menopause if postmenopausal
• Be non-smokers
• Be fluent in English

Exclusion criteria

- Unwilling to be filmed during the stress task OR unwilling to sign the waiver allowing their filmed responses to be used in scientific presentations

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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38 participants in 2 patient groups

Stress (sympathetic nervous system activation)

Experimental group

Description:

Stress will be induced using the socially evaluated cold pressor test. Participants will complete three rounds of the socially evaluated cold pressor test. The socially evaluated cold pressor test involves submerging one hand in ice-cold water for 3 minutes while participants' reactions are filmed on camera.

Treatment:

Behavioral: Sympathetic Nervous System Activation

No-stress

Sham Comparator group

Description:

Participants will hold a hand in room temperature water for 3 minutes.

Treatment:

Behavioral: No-stress