The long-term prognostic significance of repeated blood pressure measurements in the elderly - SPAA (Studio sulla Pressione Arteriosa nell'Anziano) 10-year follow-up

Background: In young and middle-aged people, both systolic (SBP) and diasto lic (DBP) blood pressure have a continuous, strong, and independent relatio nship with subsequent cardiovascular morbidity and mortality. These relatio nships are not well documented in older people and, until now, studies in t he elderly do not provide homogeneous results on the importance of DBP comp ared with SEP as a cardiovascular risk factor. Objective: To determine whether SEP and DBP are independent indicators of m ortality risk in the elderly. Design: An observational prospective cohort study to analyze the long-term prognostic significance of repeated SEP and DBP measurements in the elderly . Patients and Methods: A total of 3858 outpatients 65 years or older (mean a ge [SD], 72.9 [4.9] years, 43.5% men) were selected randomly by 444 Italian National Health Service general practitioners in 1983. The population was followed up for 10 years. Crude and adjusted incidence rates of total and c ardiovascular mortality were analyzed for classes of SEP and DBP based on t he values recorded at the 2 initial visits 1 week apart and those measured during the first 12 months of follow-up. Results: During the 10- year follow-up, 74 patients (1.9%) were lost to fol low-up and 1561 (41.3%) died, 709 (45.4% of all deaths) from cardiovascular causes. A positive continuous, graded, strong, and independent association was observed with both total (P<.001) and cardiovascular (P<.001) mortalit y for SEP but not for DBP. The pattern was similar in both sexes, in person s younger and older than 75 years, regardless of preexisting cardiovascular diseases, and whether they had been receiving antihypertensive treatment a t baseline. There was no J-shaped mortality curve in the subjects with the lowest SEP and DBP. Conclusions: These findings suggest that SEP, but not DBP, is a strong, pos itive, continuous, independent indicator of mortality risk in the elderly a nd should be stressed much more than DBP in the diagnosis and treatment of hypertension in this age group.