The Influence Of Body Positions On Blood Pressure In Hypertensive Patients

Objective To study blood pressure variation patterns according to body positions, and to explore the possible factors that associated with blood pressure(BP) among standing, sitting and supine position in patients with hypertension. Methods Standing, sitting and supine BP was measured in turns in 334 hypertensive patients, who were choosed frome clinic and division of hypertension, using a standard mercury sphygmomanometer(CBP) and ambulatory blood pressure monitoring(ABP),and each position must hold on for two hours. During test, ABP measured BP per 15 minutes, while CBP was measured after endpoint of each posture. Clinical characteristics and medication,such as patient's body weight, height, bilateralis pulses and blood glucose levels were also measured. Results Both systolic and diastolic blood pressures(SBP and DBP respectively) were significantly different among standing, sitting and supine positions except ABP-SBP. CBP-SBP in supine position was higher compared to standing and sitting position [by 6.0±1.0 mm Hg/2.6±0.9mmHg respectively, P<0.05], but CBP-DBP in supine position was lower than in standing and sitting position [by1.8±0.8 mmHg/2.4±0.7mmHg respectively,P<0.05];ABP-DBP were significantly lower in supine position than in standing and sitting position [by 7.3±0.8mmHg/7.2±0.7mmHg respectively, P<0.05]. Except supine DBP, both ABP-BP were significantly higher than CBP-BP in standing, sitting and supine positions. Multivariate regression analysis showed that duration of hypertension, gender and fasting blood glucose were independent factors of SBP variation (P<0.05), while age and cholesterol were independent predictors for DBP variation (P<0.05). Conclusions The change of body positions contributes to blood pressure measured values in hypertensive patients. Blood pressure measured values are significant differenct in each position. Factors as course of hypertension, age, FBG, and cholesterol can influence blood pressure variation among standing,sitting and supine positions.