Evidence for elevated pulse pressure in patients on chronic hemodialysis: a case-control study.

BACKGROUND Few analyses have compared pulse pressure (PP) values in hemodialysis patients with healthy individuals, and they have provided only limited data. We retrospectively examined PP in a large cohort of hemodialysis patients and healthy control subjects. METHODS The relationships of systolic blood pressure (SBP), diastolic blood pressure (DBP), and PP to mean arterial pressure (MAP) levels were investigated in 234 chronic hemodialysis patients and in 682 control subjects matched for age, sex, diabetes mellitus, and body mass index. RESULTS In both control and patients, PP was positively correlated with MAP, and the two regression lines were parallel (beta of control subjects = 0.52; beta of hemodialysis patients = 0.57, P = 0.48). According to the regression line, at any MAP level, the PP in hemodialysis patients was significantly higher than that in control subjects: the mean PP difference between control and patients was 19.2 mm Hg (95% CI, 17.2 to 21.1 mm Hg, P < 0.0001). When the relationships between MAP and SBP and that between MAP and DBP were analyzed, the regression lines were also parallel. However, at any MAP level, SBP was higher and DBP was lower in hemodialysis patients than control subjects; the mean SBP difference was 12.8 mm Hg (95% CI, 11.5 to 14.1 mm Hg, P < 0.0001) and mean DBP difference was 6.4 mm Hg (95% CI, 5.7 to 7.0 mm Hg, P < 0.0001). CONCLUSIONS At any MAP level, hemodialysis patients had a higher SBP, lower DBP, and higher PP values than those control subjects with a normal renal function who were matched for age, sex, diabetes mellitus, and body mass index. Further study is needed to determine whether preventing or reducing an elevated PP improves the prognosis for hemodialysis patients.