# Multilevel Determinants of Circadian Factors and Sleep Disruption: Implications for Cardiometabolic Health Among African-Americans

> **NIH NIH R01** · EMORY UNIVERSITY · 2023 · $780,010

## Abstract

PROJECT SUMMARY/ABSTRACT
 Significance. Circadian and sleep disruption, and sleep disorders such as sleep apnea, are highly
prevalent and associated with a host of adverse health outcomes including cardiovascular mortality and
morbidity. African-Americans are disproportionately affected by disrupted/misaligned circadian rhythms,
disrupted sleep and sleep apnea; which may be important, unique contributors to adverse CMB health in
African-Americans. Reducing the burden of adverse cardiometabolic health in African-Americans may involve
targeting both circadian rhythms and sleep. However, limited research exists on circadian rhythms in the
natural environment of AAs, and there are major gaps in knowledge about the determinants of circadian and
sleep disruption within African-Americans. We hypothesize that multilevel socio-environmental factors are
drivers of circadian misalignment (a mismatch between the internal circadian system and behavioral or
environmental cycles), which contribute to irregular sleep, and in turn disrupts physiologic processes such as
blood pressure and metabolism in a socioeconomically diverse cohort of AAs. It is plausible that the
hypothesized association differs by SES and individual resilience; thus, we will consider resilience as a
protective factor that may mitigate the adverse effects of the environment. Approach. Leveraging resources
from a well characterized cohort of African-Americans in Atlanta Georgia, we propose to use a repeated
measures design to test the cumulative effects of real-time household- and neighborhood-level factors (e.g.,
socioeconomic status, light at night, noise, air pollution) on psychosocial factors, rigorously assessed circadian
disruption/misalignment (including home dim light melatonin onset to measure internal endogenous biologic
rhythms), sleep regularity (14-day actigraphy, diary) and apnea (in-home polysomnography) and relatedly, the
impact of these measures on markers of CMB health in 400 AAs. To assess cardiometabolic health we will
measure 24-hour blood pressure, arterial stiffness, and biochemical markers of inflammation and metabolic
dysfunction. We will explore individual-level SES and resilience as effect modifiers of the hypothesized
associations. Impact. The overarching aim of this R01 is to elucidate the largely unexplained high burden of
adverse cardiometabolic health in African-Americans by specifically focusing on identifying the multilevel socio-
environmental determinants of circadian and sleep disruption, and determining the relative impact of circadian
and sleep disruption on markers of CMB health. This project will have a high impact, because it will identify
salient socio-environmental factors (risk and protective) that contribute to circadian and sleep health in AAs, to
inform culturally tailored multilevel interventions to reduce sleep and cardiovascular disparities.

## Key facts

- **NIH application ID:** 10692699
- **Project number:** 5R01HL157954-02
- **Recipient organization:** EMORY UNIVERSITY
- **Principal Investigator:** Dayna Johnson
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $780,010
- **Award type:** 5
- **Project period:** 2022-09-01 → 2027-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10692699

## Citation

> US National Institutes of Health, RePORTER application 10692699, Multilevel Determinants of Circadian Factors and Sleep Disruption: Implications for Cardiometabolic Health Among African-Americans (5R01HL157954-02). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10692699. Licensed CC0.

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