title: Impact of Visit-to-Visit Variability in Systolic Blood Pressure on Cardiovascular Outcomes in Korean National Health Insurance Service-National Sample Cohort.
abstract: BACKGROUND
  Despite an association between visit-to-visit blood pressure (BP) variability (VV-BPV) and cardiovascular (CV) outcomes, many studies performed during the past 4 years have shown conflicting results. This study investigated the impact of VV-BPV on CV outcomes in the Korean National Health Insurance Service (NHIS) database-National Sample Cohort.
  
  
  METHODS
  From the 2002 Korean NHIS database (n = 47,851,928), sample subjects with 3 or more BP measurements (n = 51,811) were divided into 2 groups according to a 10 mm Hg cutoff in the SD of systolic BP (SD-SBP). The CV outcomes of these groups were compared by sensitivity analyses using various sampling methods.
  
  
  RESULTS
  Irrespective of sampling method, subjects with SD-SBPs ≥10 mm Hg had higher rates of CV events or death, nonfatal myocardial infarction (MI) or stroke, and total mortality, but were not associated with CV mortality. The hazard ratios for CV events or death, nonfatal MI or stroke, CV mortality, and total mortality were 1.43 (95% confidence interval [CI], 1.25-1.63, P < 0.01), 1.45 (95% CI, 1.27-1.65, P < 0.01), 1.32 (95% CI, 0.89-1.94, P = 0.17), and 1.18 (95% CI, 1.01-1.38, P = 0.04), respectively.
  
  
  CONCLUSIONS
  Increased VV-BPV was an independent risk factor for future CV outcomes, independent of mean BP status, even in normotensive subjects and in all subgroups, except females. Similar VV-BPV values in the sensitivity analyses suggest VV-BPV is a reproducible phenomenon, reflecting the various types of intrinsic physiologic properties.
authors.affiliation: Department of Cardiology, Department of Internal Medicine, Guri Hospital, College of Medicine, Hanyang University, Guri, Korea.
authors.forename: SeongIl
authors.initials: S
authors.lastname: Choi
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea.
authors.forename: Jinho
authors.initials: J
authors.lastname: Shin
authors.affiliation: Department of Preventive Medicine, Hanyang University College of Medicine, Seoul, South Korea.
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Division of Cardiology, Department of Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Ki Chul
authors.initials: KC
authors.lastname: Sung
authors.affiliation: Department of Internal Medicine, Catholic University, College of Medicine, Bucheon, Korea.
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Ihm
authors.affiliation: Department of Internal Medicine, Seoul National University, School of Medicine, Bundang, Korea.
authors.forename: Kwang-Il
authors.initials: KI
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, Dong-A University College of Medicine, Busan, South Korea.
authors.forename: Yu-Mi
authors.initials: YM
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D001795:Blood Pressure Determination; D002423:Cause of Death; D016208:Databases, Factual; D005260:Female; D006306:Health Surveys; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality / Q000503:physiopathology*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000503:physiopathology; D009819:Office Visits; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000503:physiopathology; D013997:Time Factors
keywords: blood pressure; cardiovascular outcome; hypertension; mortality; variability.