title: Lower systolic blood pressure is associated with greater mortality in people aged 85 and older.
abstract: OBJECTIVE
  To investigate the association between blood pressure and mortality in very old people.
  
  
  METHODS
  Population-based cohort study.
  
  
  METHODS
  County of Västerbotten, Sweden.
  
  
  METHODS
  Half of all subjects aged 85 and all of those aged 90 and 95 and older (N=348) in one urban and five rural municipalities in the north of Sweden.
  
  
  METHODS
  Among others, supine blood pressure, Mini-Mental State Examination, Barthel Index of activities of daily living, Mini Nutritional Assessment, and body mass index. Information on diagnoses, medications, and 4-year mortality was collected. Associations between blood pressure and mortality were investigated using Cox regression analyses, controlling for a number of diagnoses and health factors.
  
  
  RESULTS
  Baseline systolic blood pressure (SBP), diastolic blood pressure, and pulse pressure were all inversely associated with mortality within 4 years according to univariate analysis. SBP was the strongest predictor. In Cox regression analyses, low SBP (<or=120 mmHg) correlated with greater 4-year all-cause mortality alone and when controlling for health status. This connection persisted after exclusion of deaths within the first year. There was a tendency toward a U-shaped mortality curve for the adjusted model, with SBP of 164.2 mmHg (95% confidence interval=154.1-183.8 mmHg) being associated with the lowest mortality.
  
  
  CONCLUSIONS
  Lower SBP seems to be associated with greater mortality in people aged 85 and older, irrespective of health status. There are indications of a U-shaped correlation between SBP and mortality, and the optimal SBP for this age group could be above 140 mmHg.
authors.affiliation: Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, Umeå, Sweden. lena.molander@germed.umu.se
authors.forename: Lena
authors.initials: L
authors.lastname: Molander
authors.forename: Hugo
authors.initials: H
authors.lastname: Lövheim
authors.forename: Tove
authors.initials: T
authors.lastname: Norman
authors.forename: Peter
authors.initials: P
authors.lastname: Nordström
authors.forename: Yngve
authors.initials: Y
authors.lastname: Gustafson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D015897:Comorbidity; D005260:Female; D006801:Humans; D006973:Hypertension / Q000401:mortality; D008297:Male; D009026:Mortality; D012959:Socioeconomic Factors; D016019:Survival Analysis; D013548:Sweden / Q000453:epidemiology; D013599:Systole