title: Sedentary behavior and blood pressure control among osteoarthritis initiative participants.
abstract: OBJECTIVE
  To examine the association between sedentary behavior and blood pressure (BP) among Osteoarthritis Initiative (OAI) participants.
  
  
  METHODS
  We conducted a cross-sectional analysis of the OAI 48-month visit participants whose physical activity was measured using accelerometers. Participants were classified into four quartiles according to the percentage of wear time that was sedentary (<100 activity counts per min). Users of antihypertensive medications or non-steroidal anti-inflammatory drugs (NSAIDs) were excluded. Our main outcomes were systolic and diastolic blood pressures (SBP and DBP) and "elevated BP" defined as BP ≥ 130/85 mm Hg.
  
  
  RESULTS
  For this study cohort (N = 707), mean BP was 121.4 ± 15.6/74.7 ± 9.5 mm Hg and 33% had elevated BP. SBP had a graded association with increased sedentary time (P for trend = 0.02). The most sedentary quartile had 4.26 mm Hg higher SBP (95% confidence interval (CI), 0.69-7.82; P = 0.02) than the least sedentary quartile, adjusting for age, moderate-to-vigorous (MV) physical activity, and other demographic and health factors. The probability of having elevated BP significantly increased in higher sedentary quartiles (P for trend = 0.046). There were no significant findings for DBP.
  
  
  CONCLUSIONS
  A strong graded association was demonstrated between sedentary behavior and increased SBP and elevated BP, independent of time spent in MV physical activity. Reducing daily sedentary time may lead to improvement in BP and reduction in cardiovascular risk.
authors.affiliation: Center of Innovation for Complex Chronic Healthcare, Hines VA Hospital, Hines, IL, USA; Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. Electronic address: msohn@northwestern.edu.
authors.forename: M-W
authors.initials: MW
authors.lastname: Sohn
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. Electronic address: l-manheim@northwestern.edu.
authors.forename: L M
authors.initials: LM
authors.lastname: Manheim
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. Electronic address: rwchang@northwestern.edu.
authors.forename: R W
authors.initials: RW
authors.lastname: Chang
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. Electronic address: p-greenland@northwestern.edu.
authors.forename: P
authors.initials: P
authors.lastname: Greenland
authors.affiliation: University of Maryland School of Medicine, Baltimore, MD, USA. Electronic address: mhochber@medicine.umaryland.edu.
authors.forename: M C
authors.initials: MC
authors.lastname: Hochberg
authors.affiliation: University of California, San Francisco, CA, USA. Electronic address: mnevitt@psg.ucsf.edu.
authors.forename: M C
authors.initials: MC
authors.lastname: Nevitt
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. Electronic address: p-semanik@northwestern.edu.
authors.forename: P A
authors.initials: PA
authors.lastname: Semanik
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. Electronic address: ddunlop@northwestern.edu.
authors.forename: D D
authors.initials: DD
authors.lastname: Dunlop
mesh_terms: D061725:Accelerometry / Q000379:methods; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009765:Obesity / Q000453:epidemiology / Q000503:physiopathology; D020370:Osteoarthritis, Knee / Q000453:epidemiology / Q000503:physiopathology*; D057185:Sedentary Behavior; D014481:United States / Q000453:epidemiology
keywords: Blood pressure; Osteoarthritis; Physical activity; Sedentary lifestyle