Impact of postures on blood pressure in healthy subjects

Controversies exist on the nature of influence of body position on the level of blood pressure. This study was designed to investigate the impact of postures on blood pressures in healthy subjects.

Blood pressure was measured in 6,485 healthy subjects in both supine and sitting positions, using a standard mercury sphygmomanometer.

The average systolic and diastolic blood pressure in all age groups in the supine position was higher than in the sitting position (P < 0.001). There was a reduced systolic pressure increment but enhanced diastolic pressure increment with aging (P < 0.05). The levels of sitting blood pressure were inversely correlated to the pressure increments in supine positions (P < 0.001). Multivariate regression analysis showed that age is an independent factor for the systolic pressure increment in the supine position (P < 0.001), whereas sex, age, body height and body mass index are independent predictors for the increment in diastolic blood pressure (P < 0.001).

In healthy subjects, blood pressure in the supine position is higher than in the sitting position and age plays an important part in this posture-related pressure increment.