[Differences of age and gender in orthostatic
hypertension-a single-center study]

To explore the differences of Chinese people's age and gender in orthostatic hypertension (OHT) by a single-center experience study.

A total of 2 994 patients with unexplained syncope and dizziness, who were outpatients or had been hospitalized in Second Xiangya Hospital, Central South University from January 2000 to August 2012, were chosen and subjected to the head-up tilt table test (HUTT). Their ages ranged from 2.00 to 78.00 years old, with an average at 19.07±14.78 years old. There were 1 406 and 1 588 cases for male and female, respectively. A total of 745 patients were OHT, who were divided into a adult group (≥18 years old, 247/904 cases) and a children group (<18 years old, 498/2 090 cases). The difference of the occurrence rate, classification, and 3 min quantity of blood pressure were analyzed.

1) The incidence of OHT in HUTT was 24.88% (745/2 994 cases). There was no statistical difference between the males and the females(25.75% vs 24.12%, χ2=1.058, P>0.05), but it was higher in the adult group compared with that in the children group (27.05% vs 23.83%, χ2=4.125, P=0.042). There were 52 cases (6.98%) of high systolic and high diastolic blood pressure (sOHT merge dOHT), 16 cases (2.15%) of simple high systolic blood pressure OHT (sOHT), and 677 cases (90.87%) of simple high diastolic blood pressure OHT (dOHT) in the 745 patients with OHT. The incidence of dOHT and sOHT merge sOHT in the adults group were significantly higher than those in the children group (1.11% vs 0.29%, χ2=7.965, P<0.01; 2.88% vs 1.24%, χ2=9.849, P<0.01, respectively); there was no statistical difference in simple dOHT between males and females (23.56% vs 22.20%, χ2=0.668, P>0.05); there was also no statistical difference in sOHT plus dOHT and dOHT between males and females (sOHT merge dOHT: 1.71% vs 1.76%, χ2=0.014, P>0.05; dOHT: 23.68% vs 21.66%, χ2=1.742, P>0.05; 1.71% vs 1.76%, χ2=0.014, P>0.05, respectively); but the dOHT was significantly higher in the males than that in the females in the children group (24.53% vs 19.74%, χ2=6.933, P>0.05). 2) There was no difference in the increment of systolic blood pressure in sOHT plus dOHT [(25.62±4.96) mmHg vs (23.54±5.83) mmHg, t=1.385, P>0.05] and the increment of diastolic blood pressure in dOHT [(13.46±3.49) mmHg vs (13.23±3.22) mmHg, t=0.840, P>0.05] between the adults group and the children group. There was no difference in the increment of systolic blood pressure in sOHT [(25.44±4.96) mmHg vs (23.68±5.35) mmHg, t=1.411, P>0.05] and the increment of diastolic blood pressure in dOHT [(14.09±4.28) mmHg vs (13.05±3.82) mmHg, t=1.887, P>0.05] between the adults group and the children group.

The incidence of OHT is higher in the adults group than that in the children group. There is no difference in systolic and diastolic blood pressure increment within 3 minutes during HUTT between the adults and children.