title: J-shaped relationship between blood pressure and mortality in hypertensive patients: new insights from a meta-analysis of individual-patient data.
abstract: BACKGROUND
  Population-based longitudinal studies of hypertension have usually shown a continuous and positive relationship between blood pressure and mortality. However, several studies in hypertensive patients receiving treatment have described this relationship as J-shaped, with an increased risk for events in patients with low blood pressure.
  
  
  OBJECTIVE
  To assess the evidence for a J-shaped relationship between blood pressure and mortality and its relation to treatment.
  
  
  METHODS
  Meta-analysis of individual-patient data.
  
  
  METHODS
  Seven randomized clinical trials from the INDANA (INdividual Data ANalysis of Antihypertensive intervention) database.
  
  
  METHODS
  40 233 persons with hypertension (mean follow-up, 3.9 years).
  
  
  METHODS
  Primarily beta-blockers or thiazide diuretics versus placebo or no treatment.
  
  
  METHODS
  Diastolic and systolic blood pressure and number of cardiovascular, noncardiovascular, and all-cause deaths in yearly periods of follow-up.
  
  
  RESULTS
  The analysis included data on 1655 deaths (56% cardiovascular). A J-shaped relationship between diastolic blood pressure and risk for death was observed for total and cardiovascular mortality in treated patients (nadir, 84 and 80 mm Hg, respectively) and untreated patients (nadir, 90 and 85 mm Hg, respectively). For noncardiovascular deaths, the relationship was J-shaped in the treated group (nadir, 84 mm Hg) and negative in the control group. Similar results were observed for systolic blood pressure. The presence of patients with wide pulse pressure did not explain these findings.
  
  
  CONCLUSIONS
  The increased risk for events observed in patients with low blood pressure was not related to antihypertensive treatment and was not specific to blood pressure-related events. Poor health conditions leading to low blood pressure and an increased risk for death probably explain the J-shaped curve.
authors.affiliation: Claude Bernard University, Lyon, France. flb@upcl.univ-lyon1.fr
authors.forename: Florent
authors.initials: F
authors.lastname: Boutitie
authors.forename: François
authors.initials: F
authors.lastname: Gueyffier
authors.forename: Stuart
authors.initials: S
authors.lastname: Pocock
authors.forename: Robert
authors.initials: R
authors.lastname: Fagard
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Boissel
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000209:etiology / Q000401:mortality; D005260:Female; D006304:Health Status; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy / Q000401:mortality* / Q000503:physiopathology*; D008297:Male; D012307:Risk Factors
chemical_list: D000959:Antihypertensive Agents