title: The Mediation of Racial Differences in Hypertension by Sleep Characteristics: Chicago Area Sleep Study.
abstract: Racial disparities in hypertension prevalence in the United States are established. Given our understanding of racial and ethnic disparities in sleep characteristics and demonstrated associations between sleep characteristics and hypertension, we tested whether sleep characteristics mediated racial disparities in hypertension.
  
  
  
  Analyses were performed in the Chicago Area Sleep Study, a population-based cohort study of 154 Blacks, 128 Whites, 103 Hispanics, and 109 Asians without obstructive sleep apnea. Participants underwent 7 days of wrist actigraphy monitoring. Algorithms were used to determine sleep duration and sleep maintenance (the percent of sleep in the sleep period). Hypertension was determined as systolic blood pressure >140mm Hg or diastolic blood pressure >90mm Hg or the use of antihypertensive medications. We estimated sample prevalence ratios for hypertension before and after adjustment for sleep characteristics and also conducted mediation analysis.
  
  
  
  The sample prevalence of hypertension was highest in Blacks (36%), followed by Hispanics (14%), Asians (8%), and Whites (5%). The sample prevalence ratio for hypertension for Blacks vs. Whites was 5.52 (95% confidence interval (CI): 2.36, 13.23) after adjusting for age, sex, and education. Adjustment for sleep duration had no influence on the effect estimate, but adjustment for sleep maintenance attenuated the sample prevalence ratio to 4.55 (95% CI: 1.91, 11.14). Sleep maintenance mediated 11.4% of the difference in hypertension prevalence between Blacks and Whites in this sample.
  
  
  
  Sleep maintenance mediated a small but significant portion of the disparity in hypertension between Blacks and Whites. Future research should investigate the mechanisms underlying these findings.
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Rasmussen-Torvik
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Peter John D
authors.initials: PJD
authors.lastname: De Chavez
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Kiarri N
authors.initials: KN
authors.lastname: Kershaw
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Samantha E
authors.initials: SE
authors.lastname: Montag
authors.affiliation: Department of Medicine, University of Chicago, Chicago, Illinois, USA.
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Knutson
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Kwang-Youn A
authors.initials: KA
authors.lastname: Kim
authors.affiliation: Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
authors.forename: Phyllis C
authors.initials: PC
authors.lastname: Zee
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Mercedes R
authors.initials: MR
authors.lastname: Carnethon
mesh_terms: D000328:Adult; D001741:Black or African American; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001213:Asian; D001794:Blood Pressure / Q000187:drug effects; D002641:Chicago / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D054624:Health Status Disparities; D006630:Hispanic or Latino; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000188:drug therapy / Q000208:ethnology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012890:Sleep; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000208:ethnology* / Q000503:physiopathology; D013997:Time Factors; D044465:White People
chemical_list: D000959:Antihypertensive Agents
keywords: blood pressure; hypertension; mediation; racial disparities.; sleep maintenance