Table 1.

Demographic Data and Orthostatic Vital Signs

	POTS (n = 87)	Control (n = 39)	P-value
Age, median years (IQR)	27 (19 - 37)	24 (23 - 29)	0.699
Female, n (%)	82 (94%)	36 (92%)	0.400
Education Level, years	15 ± 3	16 ± 2	0.110
Systolic Blood Pressure (mmHg)
Supine	114 ± 12	110 ± 10	0.087
Standing	115 ± 14	115 ± 11	0.836
Standing-Supine	2 ± 10	4 ± 7	0.141
Diastolic Blood Pressure (mmHg)
Supine	74 ± 10	69 ± 7	0.004*
Standing	86 ± 11	74 ± 6	>0.001*
Standing-Supine	13 ± 7	5 ± 5	>0.001*
Heart Rate (beats/min)
Supine	77 ± 14	71 ± 12	0.035*
Standing	91 ± 17	83 ± 12	0.0*
Standing-Supine	15 ± 10	13 ± 7	0.188
Heart Rate change > 30 beats/min
n (%)	9 (10)	0 (0)	>0.001*

Blood pressure and heart rate values obtained after 5 minutes in the supine and standing postures are reported. IQR, interquartile range. Data are shown as mean±SD unless otherwise noted.

^*P < 0.05