¹Istituto Medicina Cardiovascolare and Centro Fisiologia Clinica e Ipertensione, Università di Milano and Ospedale Maggiore IRCCS, Milano, Italy.

Correspondence: Dr. Carla Sala, Centro Fisiologia Clinica e Ipertensione, Policlinico-Via F. Sforza 35, 20122 Milano, Italy E-mail: carla.sala@unimi.it

Received 8 July 2004; Revised 8 September 2004; Accepted 8 September 2004.

Abstract

Background: In clinical practice, blood pressure (BP) is frequently measured at the end of the visit in patients sitting on one side of the bed and not on a chair according to guidelines.

Methods: In 540 consecutive subjects with essential hypertension (EH) attending a hospital outpatient clinic, BP was measured in the following sequence: 1) patient seated on chair for at least 5 min, 2) patient supine, 3) patient seated on bed, and 4) patient standing for a few minutes.

Results: We found that mean (SEM) BP was 143.5/87.2 0.9/0.5, 153.4/89.7 1.0/0.5, 148.9/90.9 1.0/0.5, and 144.8/91.7 1.0/0.6 mm Hg, respectively (P < .05 v position 1 for all). In 14% of patients, either systolic BP (SBP) or diastolic BP (DBP) was above the conventional upper limits of normality in the seated-on-bed but not in the recommended seated-on-chair position ("false" high clinic BP), whereas SBP and DBP were "false" normal (below limit for bed-seated and above limit for chair-seated position) in only 6% and 2% of patients, respectively. Overall, SBP and DBP increments from the chair- to the bed-seated position were inversely related to the baseline chair-seated values; systolic increments were directly related to age, in particular in the subgroup of untreated EH (n = 70), and to body mass index. A gender-related difference was apparent, as female subjects had more pronounced increments in SBP (+7.4 0.8 v +3.5 0.7 mm Hg) and DBP (+4.4 0.5 v 2.9 0.4 mm Hg) than did male subjects (P < .05 for both).

Conclusions: Clinic SBP and DBP are overestimated in the bed-seated position at the end of the visit compared with the recommended chair-seated position in treated and untreated patients with EH, in particular in elderly obese women with mild hypertension.