title: Changes in blood pressure in a large cohort of elderly individuals: Study 3C.
abstract: OBJECTIVE
  Analysis of changes in blood pressure with a two-year interval, and of factors associated with this change, in a large cohort of elderly individuals.
  
  
  METHODS
  Follow-up of a cohort of 9294 individuals aged 65 years and over recruited from the general population for Study 3C. Changes in blood pressure are defined as the difference in its averages between the inclusion visit and the follow-up visit at 2 years. The factors associated with changes in systolic blood pressure were identified by univariate and multivariate analyses.
  
  
  RESULTS
  Systolic and diastolic blood pressure decreased on average by 7.60 mmHg and 4.45 mmHg respectively in 7659 individuals included in the study between the initial measurement and the follow-up at 2 years. The analyses revealed that the initial high blood pressure level was the main factor for this decrease that would be explained by a phenomenon of regression towards the mean.
  
  
  CONCLUSIONS
  These results confirm the importance of repeating blood pressure measurements during several examinations for a good estimate of individual blood pressure values in this age range. It is also important to consider this phenomenon in studies including specific blood pressure estimates only.
authors.affiliation: INSERM U708 Neuroepidemiology, Hospital La Salpetriere Paris, and UPMC University of Paris 06, Paris, France.
authors.forename: Mohand
authors.initials: M
authors.lastname: Lachouri
authors.forename: Véronique
authors.initials: V
authors.lastname: Gourlet
authors.forename: Philippe
authors.initials: P
authors.lastname: D'Athis
authors.forename: Christophe
authors.initials: C
authors.lastname: Tzourio
authors.forename: Catherine
authors.initials: C
authors.lastname: Quantin
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D001795:Blood Pressure Determination; D005260:Female; D005500:Follow-Up Studies; D005602:France; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents