Comparison of Office Blood Pressures in Supine, Sitting and Standing Positions with Ambulatory Blood Pressures

This study was performed in 88 patients with mild to moderate hypertension with the aim to demonstrate the variability of blood pressure in accordence with the position of the body. Blood pressure of the patients was measured in supine, sitting and standing positions twice for two days followed by 24-hour ambulatory blood pressure monitoring. Mean blood pressures in supine, sitting and standing positions were 147±12/92±7, 151±13/97±8 and 156±13/103±7 mmHg, respectively. The mean of all three positions was 151±12/97±7 mmHg. Diastolic blood pressures were significantly different from each other in each position (p<0.01). Systolic blood pressures were not found to be different in supine and sitting positions but both were significantly different from the standing systolic pressure (p<0.01). The mean awake and 24- hour ambulatory blood pressures were '147±12/ 90±7 and 141±12/85±7 mmHg respectively. Carrelation coefficients of office blood pressures and ambulatory blood pressures were 0.74 to 0.80 for systolic pressure and 0.55 to 0.65 for diastolic pressure depending on the position of the body. The best correlation was obtained with the mean awake ambulatory blood pressure and the mean of office blood pressures in all positions (systolic 0.80, diastolic 0.65). It was confirmed that the position of the body influences the estimation of blood pressure; hence, it would be most reliable to use the values obtained in the sitting position.