Differences in blood pressure readings between supine and sitting positions in hypertensive patients

Objectives: To investigate the impact of postures on blood pressure (BP) readings in patients with hypertension.Methods and results: BP was measured in 1,487 hypertensive patients in sitting and supine positions. The systolic (SBP) and diastolic (DBP) BP in supine position was 2.9 ± 7.8mmHg and 0.9 ± 5.4 mmHg higher, respectively, than in the sitting position (P<0.001). The greatest difference between supine and sitting SBP was found in those aged between 30 and 39 (3.6 ± 6.8mmHg), and in those who were older than 80 (5.3 ± 7.9 mmHg). A greater difference between the supine and sitting DBP was identified in the > 60-year groups. Multivariate regression analysis showed that age and sex were independent predictors for the increment of BP in the supine position.Conclusions: There is a significant difference between supine and sitting SBP and DBP, with age and sex being the most important predicting factors.