Pulse pressure, prehypertension, and mortality: the San Antonio heart study

Abstract

Background: Prehypertension increases mortality risk. Pulse pressure is also associated with increased mortality. Nevertheless, the impact of pulse pressure on the relationship between prehypertension and mortality is not known in individuals who are free of diabetes and cardiovascular disease.

Methods: Cox regression analysis was used to examine mortality risk among 3,632 (97.0%) participants in the San Antonio Heart Study (age range, 25-64 years; mean follow-up, 15.2 years). Results were adjusted for age, sex, ethnicity, education, body mass index (BMI), smoking, and total cholesterol concentration. The Seventh Report of the Joint Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) categories were used for blood pressure staging: normal, <120/80 mm Hg; prehypertension, 120-139/80-89 mm Hg.

Results: Prehypertension prevalence was 31.6% at baseline. There were 218 deaths during the follow-up period. Prehypertension-predicted mortality (all-cause, hazard ratio (HR) 1.49 (1.12-1.99); cardiovascular, HR 1.79 (1.07-3.02)). Relative to normal blood pressure plus pulse pressure in the lower tertile, prehypertension plus pulse pressure in the upper tertile was associated with increased mortality (all-cause, HR 2.14 (1.38-3.32); cardiovascular, HR 2.47 (1.13-5.39)); however, prehypertension plus pulse pressure in the lower tertile was not significantly associated with mortality (all-cause, HR 1.19 (0.52-2.67); cardiovascular, HR 0.43 (0.05-3.40)).

Conclusions: Prehypertension increases mortality risk (all-cause and cardiovascular) in individuals who are free of diabetes and cardiovascular disease. Nevertheless, this relationship is not evident in individuals with narrow pulse pressure. Therefore, pulse pressure may be a relevant measure of blood pressure for the definition of normal blood pressure.