Sleep and Social Experiences Study 2

Study Overview
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Brief Summary
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This study aims to to test effects of sleep loss on perceived discrimination and cardiovascular functioning as well as identify moderators of the racial discrimination and objective sleep link in a sample of 80 African Americans.

Detailed Description
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African Americans (AAs) are disproportionately burdened by clinical and subclinical cardiovascular disease (CVD) when compared to European Americans (EAs), and while experiences of racial discrimination have been associated with CVD morbidity among AAs, including high daytime and nighttime blood pressure, the mechanisms underlying these associations are unclear. Poor sleep, such as short sleep duration and poor sleep continuity, may serve as a novel pathway; however, this possibility has not been rigorously tested. Evidence linking racial discrimination and poor sleep is mounting, however, largely derived from cross-sectional studies. Further, researchers have largely ignored the possibility of reciprocal effects. In a separate study (CHR#:18-24889) the investigators are testing the effects of perceived discrimination on sleep and nocturnal physiology. In this study, however, the investigators aim to test whether the other direction- whether experimental sleep loss affects one's perception and reaction to social interaction tasks with an outgroup member (White participant). To this end, the investigators will randomize 80 healthy AAs to one night of total sleep restriction or normal sleep in the sleep laboratory and then expose them to several standardized social experience tasks. These tasks include a digit span task, social evaluative speech task and cooperative task (i.e., playing Taboo), all of which will occur in the context of subtle negative evaluative feedback from the White confederate. Cardiovascular functioning as well as self-reported affect will be measured throughout the tasks and potential moderators, including socioeconomic status and race-based rejection sensitivity, will be tested. This study will fill fundamental gap in the scientific literature and provide the critical causal and mechanistic evidence necessary to address racial disparities in sleep and cardiovascular risk.

Official Title
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Sleep Loss, Cardiovascular Physiology, and Social Experiences Study

Conditions
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Sleep, Blood Pressure

Intervention / Treatment
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* Behavioral: Sleep Restriction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 18 to old 64 years old Self-identified African American/Black English speaking, able to provide informed consent Self-reported bedtime between 10 PM and 12 AM for 5/7 nights for the past 3-months (stability to be confirmed by actigraphy and sleep diary) Self-reported sleep duration of between 6.5 and 8.5 hours for 5/7 nights for the last month (duration to be confirmed by actigraphy and sleep diary) Exclusion Criteria: Aged greater than 64 years (to minimize age-related differences in sleep quantity and architecture). Body mass index of 40 or above (to exclude for obesity, which can impair physiologic recording and confound study outcomes). Presence of any clinical sleep disorder, including insomnia and obstructive sleep apnea (OSA), as assessed by validated screening measure. OSA will also be assessed objectively during the Sleep Screening period. Medical or psychiatric condition, as assessed by self-report and clinical interview, that is likely to affect sleep/wake function or cardiovascular functioning, including doctor diagnosed arrhythmia, hypertension, congestive heart failure, major depression, bipolar disorder, post-traumatic stress disorder. Medication use that is likely to affect sleep/wake function or cardiovascular functioning, including antidepressants, anxiolytic or soporific medication, and beta-blockers.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 64 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: All participants will be randomized to a night of normal sleep (8 hours) or total sleep restriction.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Normal Sleep<br>Participants will sleep in the laboratory for 8 hours and then undergo the same social-rejection paradigm as the experimental group to serve as a control comparison. | |
| Experimental: Total Sleep Restriction<br>Participants will experience a night of total sleep restriction and then undergo a social-rejection task in the morning. | Behavioral: Sleep Restriction<br>* Sleep Deprivation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in blood pressure post-rejection | Both systolic and diastolic blood pressure is measured via blood pressure arm cuff, taken after a 5-minute resting period and after each social interaction task | Baseline to post final rejection (cooperative task) an average of 32 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in pre-ejection period (PEP) in response to rejection task | Heart rate variability is measured via EKG, averaged over a 5-minute baseline period and in the minutes during the rejection task | Baseline to Post-rejection task, anticipated average of 42 minutes | 
| Change in heart rate variability (HRV) in response to rejection task | Heart rate variability is measured via EKG, averaged over a 5-minute baseline period and in the minutes during the rejection task | Baseline to Post-rejection task, anticipated average of 42 minutes | 
| Change in affect | Affect will be measured through the Positive and Negative Affect Scale (PANAS) at multiple timepoints in the study. The PANAS score is calculated by finding the sum of the 10 positive items, and then the 10 negative items. Scores can range from 10-50 for both the Positive and Negative Affect with the lower scores representing lower levels of Positive/Negative Affect and higher scores representing higher levels of Positive/Negative Affect. | Evening baseline to post-rejection task, time period of approximately 13 hours | 
| Risk-taking | Risk-taking post-social rejection will be measured through performance on the Columbia Card Task (hot version), a card game in which they can choose to turn over cards for points. Each card could either be a gain or loss card, but this is unknown until the card is turned over. Turning over gain cards result in point increases while turning over loss cards result in point decreases. Performance is scored by the average number of cards research subjects choose to turn over. Higher average scores (more cards turned over) reflect increased risk-taking. The average is generated across 20 trials of the game, with each trial containing 32 cards in total. | Immediately after final social rejection task, approximately at hour 13 of the overnight in-lab visit | 
| Trust (of outgroup partner) | Trust (of outgroup partner) will be measured via dollar amount shared in a common pot during a Public Goods game. Subjects will be told that they and their outgroup partner have the opportunity to further increase each of their monetary bonus by placing their money in a common pot that will be increased by 150% and split equally between them and their partner. Subjects can choose how much they would like to place in the common pot or choose to not share at all. Any money not placed in the common pot will be kept for themselves. Higher amounts (more dollars) shared in the common pot indicate higher levels of trust in the outgroup partner. | Public Goods game will be played after the Columbia Card Task, post-social rejection, approximately at hour 13 of the overnight in-lab visit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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sleep, heart, stress