title: The association of reduced lung function with blood pressure variability in African Americans: data from the Jackson Heart Study.
abstract: BACKGROUND
  African Americans (AAs) have lower lung function, higher blood pressure variability (BPV) and increased risk for hypertension and cardiovascular disease (CVD) compared with whites. The mechanism through which reduced lung-function is associated with increased CVD risk is unclear.
  
  
  METHODS
  We evaluated the association between percent predicted lung-function and 24-hour BPV in 1008 AAs enrolled in the Jackson Heart Study who underwent ambulatory blood pressure (BP) monitoring. Lung-function was assessed as forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and the ratio of FEV1-to-FVC during a pulmonary function test using a dry rolling sealed spirometer and grouped into gender-specific quartiles. The pairwise associations of these three lung-function measures with two measures of 24-hour BPV, (1) day-night standard deviation (SDdn) and (2) average real variability (ARV) were examined for systolic BP (SBP) and, separately, diastolic BP (DBP).
  
  
  RESULTS
  SDdn of SBP was not associated with FEV1 (mean ± standard deviation from lowest-to-highest quartile: 9.5 ± 2.5, 9.4 ± 2.4, 9.1 ± 2.3, 9.3 ± 2.6; p-trend = 0.111). After age and sex adjustment, the difference in SDdn of SBP was 0.0 (95% CI -0.4,0.4), -0.4 (95% CI -0.8,0.1) and -0.3 (95% CI -0.7,0.1) in the three progressively higher versus lowest quartiles of FEV1 (p-trend = 0.041). Differences in SDdn of SBP across FEV1 quartiles were not statistically significant after further multivariable adjustment. After multivariable adjustment, no association was present between FEV1 and ARV of SBP or SDdn and ARV of DBP or when evaluating the association of FVC and FEV1-to-FVC with 24-hour BPV.
  
  
  CONCLUSIONS
  Lung-function was not associated with increased 24-hour BPV.
authors.affiliation: University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: John N
authors.initials: JN
authors.lastname: Booth
authors.affiliation: University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Redmond
authors.affiliation: University of Mississippi Medical Center, Jackson, MS, USA.
authors.forename: Mario
authors.initials: M
authors.lastname: Sims
authors.affiliation: Columbia University Medical Center, New York, NY, USA.
authors.forename: Daichi
authors.initials: D
authors.lastname: Shimbo
authors.affiliation: University of Alabama at Birmingham, Birmingham, AL, USA. pmuntner@uab.edu.|Department of Epidemiology, University of Alabama at Birmingham, 1700 University Boulevard, LHL 440, Birmingham, AL, 35294, USA. pmuntner@uab.edu.
authors.forename: Paul
authors.initials: P
authors.lastname: Muntner
mesh_terms: D001741:Black or African American; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000503:physiopathology; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000503:physiopathology*; D016014:Linear Models; D008168:Lung / Q000502:physiology / Q000503:physiopathology*; D008171:Lung Diseases / Q000453:epidemiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D014797:Vital Capacity