Does Orthostatic Testing Have Any Role in the Evaluation of the Young Subject With Mild Hypertension?: An Insight From the HARVEST Study

Abstract The aim of the study was to assess the clinical significance of the blood pressure (BP) reaction to standing in 1029 stage I hypertensives. Office BP was measured six times in the supine position and six times after 2 min of standing. All subjects underwent 24-h ambulatory BP monitoring, and measurements of 24-h urinary epinephrine and norepinephrine excretion. Echocardiography was performed in 636 patients. With use of mixture analysis we could single out a population with abnormal diastolic BP response to standing (hyperreactors, n = 95). These subjects had a diastolic BP increase from lying to standing of>11 mm Hg. The other subjects were defined as normoreactors (n = 934). Office systolic BP was similar in the two groups. Diastolic BP was lower (91 ± 6 mm Hg v 95 ± 5 mm Hg, P< .0001) and heart rate was higher in the hyperreactors (77 ± 10 beats/min v 75 ± 9 beats/min, ). After adjusting for age, gender, and smoking habits the statistical significance did not change. Adjusted 24-h systolic BP ( ) and diastolic BP ( ) were higher in the hyperreactors than in the normoreactors. Hyperreactors were characterized by higher cardiac index (3.2 ± 0.8 L/min/m2v 3.0 ± 0.7 L/min/m2, for adjusted values), lower total peripheral resistance (1420 ± 330 dyne/sec/cm−5v 1600 ± 380 dyne/sec/cm−5, ), and higher urinary norepinephrine output (114.9 ± 80.3 h v 90.6 ± 78.5 h, ). Dimensional echocardiographic data and albumin excretion rate did not differ between the two groups. In conclusion, mixture analysis allowed us to identify a population of young mild hypertensives with exaggerated BP response to standing. Hyperreactors were characterized by higher whole-day BP and by a hyperkinetic hemodynamic pattern as a result of increased sympathetic tone.