# Racial Disparities in Sleep, Circadian Rhythm, and Glucoregulation Among Individuals Post-Coronary Artery Bypass Surgery

> **NIH NIH F31** · CASE WESTERN RESERVE UNIVERSITY · 2024 · $48,974

## Abstract

PROJECT SUMMARY/ABSTRACT
It is well established that there are racial disparities in mortality rates and postoperative outcomes following
coronary artery bypass graft with or without valvular replacement / repair (CABG/VR) surgery, particularly in
Non-Hispanic Black Americans compared to Non-Hispanic White Americans. Hospital quality and a lack of
guideline-concordant care (e.g., insulin infusions, timely antibiotics) are significant contributors; however, a large
fraction of this racial disparity remains unexplained. Sleep, circadian rhythm disruption, and impaired
glucoregulation may play a role in post-CABG/VR health disparities in Non-Hispanic Black Americans. These
disruptions may result in prolonged length of stay, postoperative convalescence, impaired immune function, and
cardiovascular morbidity and mortality. Therefore, the purpose of this descriptive study is to examine sleep and
circadian rhythm characteristics and the relationships between sleep, circadian rhythm, and glucoregulation
among adults in the intensive care unit postoperative CABG/VR surgery. In Aim 1, we will determine between-
and within-person associations of sleep, circadian rhythm and glucoregulation associations among 30 adults
post-coronary artery bypass graft with or without valvular surgery (50% non-Hispanic Black and 50% non-
Hispanic White). Sleep and circadian characteristics will be described through the timing of behavioral
(actigraphy) measures. In Aim 2, we will compare sleep, circadian rhythm characteristics, and glucoregulation
between 15 individuals identifying as Non-Hispanic Black to 15 individuals identifying as Non-Hispanic White
post-coronary artery bypass graft with or without valvular surgery. Our central hypothesis is that higher sleep
and circadian disruption are associated with poorer glucoregulation and that there are sleep, circadian, and
glucoregulation racial disparities among individuals post-CABG/VR. The proposed F31 study and training plan
will provide a strong foundation in sleep and circadian rhythm health disparities. Promoting sleep and circadian
rhythm stability post-surgery through behavioral modifications may improve glucoregulation by reducing insulin
resistance, improving insulin sensitivity, and other short- and long-term postoperative outcomes in a population
where such clinical gains may otherwise be difficult to achieve. This study will provide information on a novel
potential contributor to racial disparities in coronary artery post-operative outcomes in the ICU where it is critical
to optimize glucoregulation. Additionally, these results will provide preliminary evidence to inform future
longitudinal and intervention studies to improve glucoregulation and postoperative outcomes in this understudied
population.

## Key facts

- **NIH application ID:** 10926834
- **Project number:** 5F31NR021001-02
- **Recipient organization:** CASE WESTERN RESERVE UNIVERSITY
- **Principal Investigator:** Pamela Bolton
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $48,974
- **Award type:** 5
- **Project period:** 2023-09-01 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10926834

## Citation

> US National Institutes of Health, RePORTER application 10926834, Racial Disparities in Sleep, Circadian Rhythm, and Glucoregulation Among Individuals Post-Coronary Artery Bypass Surgery (5F31NR021001-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10926834. Licensed CC0.

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