RESPONSE TO ORTHOSTATIC STRESS PREDICTS OFFICE DAYTIME BLOOD-PRESSURE DIFFERENCE, BUT NOT NOCTURNAL BLOOD-PRESSURE FALL IN MILD ESSENTIAL HYPERTENSIVES - RESULTS OF THE HARVEST TRIAL

1. The aim of the present study was to evaluate whether postural blood pressure (BP) change could predict office-daytime BP disparity and the nocturnal BP fall in young, mild essential hypertensives. We investigated 411 males aged between 18 and 45 years with never treated borderline to mild hypertension. BP was measured three times after a 5 min rest in the supine position and thereafter three times after 2 min of standing. The mean of six BP measurements obtained during two visits in the lying position was defined as office BP. 2. Twenty-four hour ambulatory BP monitoring was performed with either the A&D TM-2420 model 7 or the ICR Spacelabs 90207. BP values were averaged for day- and nighttime periods. The nocturnal BP fall was defined as the difference between the average day- and night-time BP. 3. The standing-lying difference was significantly inversely correlated with the office-daytime difference for both systolic blood pressure (SEP) (r = -0.34, P<0.001) and diastolic blood pressure (DBP) (r = -0.24, P<0.001). These correlations did not change when the obese subjects (body mass index >30 kg/m(2)) were excluded from the analysis. No significant correlation between standing-lying difference and nocturnal BP fall was found. 4. Our results indicate that white coat hypertension assessed as the office-daytime BP disparity is partially related (in a negative fashion) to the BP reaction to standing. The postural BP change does not predict nocturnal BP fall in young, mild essential hypertensives.