title: Visit-to-visit variability of blood pressure and death, end-stage renal disease, and cardiovascular events in patients with chronic kidney disease.
abstract: OBJECTIVE
  Visit-to-visit variability of blood pressure (VVV of BP) is an important independent risk factor for premature death and cardiovascular events, but relatively little is known about this phenomenon in patients with chronic kidney disease (CKD) not yet on dialysis.
  
  
  METHODS
  We conducted a retrospective study in a community-based cohort of 114 900 adults with CKD stages 3-4 (estimated glomerular filtration rate 15-59 ml/min per 1.73 m). We hypothesized that VVV of BP would be independently associated with higher risks of death, incident treated end-stage renal disease, and cardiovascular events. We defined systolic VVV of BP using three metrics: coefficient of variation, standard deviation of the mean SBP, and average real variability.
  
  
  RESULTS
  The highest versus the lowest quintile of the coefficient of variation was associated with higher adjusted rates of death (hazard ratio 1.22; 95% confidence interval 1.11-1.34) and hemorrhagic stroke (hazard ratio 1.91; confidence interval 1.36-2.68). VVV of BP was inconsistently associated with heart failure, and was not significantly associated with acute coronary syndrome and ischemic stroke. Results were similar when using the other two metrics of VVV of BP. VVV of BP had inconsistent associations with end-stage renal disease, perhaps because of the relatively low incidences of this outcome.
  
  
  CONCLUSIONS
  Higher VVV of BP is independently associated with higher rates of death and hemorrhagic stroke in patients with moderate to advanced CKD not yet on dialysis.
authors.affiliation: aStanford University School of Medicine, StanfordbDivision of Research, Kaiser Permanente Northern California, OaklandcDepartments of Epidemiology, Biostatistics and Medicine, University of California, San Francisco, California, USA.
authors.forename: Tara I
authors.initials: TI
authors.lastname: Chang
authors.forename: Grace H
authors.initials: GH
authors.lastname: Tabada
authors.forename: Jingrong
authors.initials: J
authors.lastname: Yang
authors.forename: Thida C
authors.initials: TC
authors.lastname: Tan
authors.forename: Alan S
authors.initials: AS
authors.lastname: Go
mesh_terms: D054058:Acute Coronary Syndrome / Q000453:epidemiology; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology; D001795:Blood Pressure Determination; D002140:California / Q000453:epidemiology; D002423:Cause of Death; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000401:mortality* / Q000503:physiopathology*; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology