Changes in blood pressure in a large cohort of elderly individuals: Study 3C

SummaryObjectiveAnalysis of changes in blood pressure with a two-year interval, and of factors associated with this change, in a large cohort of elderly individuals.MethodsFollow-up of a cohort of 9294individuals aged 65years 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 2years. The factors associated with changes in systolic blood pressure were identified by univariate and multivariate analyses.ResultsSystolic and diastolic blood pressure decreased on average by 7.60mmHg and 4.45mmHg respectively in 7659individuals included in the study between the initial measurement and the follow-up at 2years. 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.ConclusionThese 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