Table 1.

Characteristics of hand vein subjects: Demographic, physical, and physiological. The left side of the table is for all subjects together. No differences were noted between pre- and post-study vital signs (P > 0.05). The right side shows the male and female subjects separately with standard errors. The P value reflects differences between the sexes

Baseline characteristics	Mean N = 18	SEM	Males N = 11	Females N = 7	P Value
Age (years)	33.2	2.8	30.5 ± 3.6	37.4 ± 4.6	0.25
Weight (kg)	74.3	3.8	81.8 ± 4.5	62.6 ± 3.8	0.008
Height (m)	1.7	0.03	1.77 ± 0.02	1.61 ± 0.02	<0.001
BMI (kg/m2)	25.1	0.86	25.8 ± 1.1	24.1 ± 1.4	0.35
Baseline dorsal hand vein diameter (mm)	0.73	0.07	0.84 ± 0.1	0.55 ± 0.03	0.043
Dose of phenylephrine required for vasoconstriction to ~70% (ng/min)	1620	460	1900 ± 700	1171 ± 470	0.46
Hand vein constriction with phenylephrine (%)	69.3	3.4	68.6 ± 5.0	70.3 ± 4.3	0.82
Dose phenylephrine/percent hand vein constriction (ng/min/percent constriction)	21.8	6.2	26.0 ± 9.4	15.3 ± 6.0	0.42
	%		%	%
Ethnicity					0.81
White	50		54.5	42.9
Black	5.6		0	14.3
East Asian	33.3		36.4	28.6
South Asian	11.1		9.1	14.3
Family history of hypertension					0.011
Yes	22.2		0	57.1
No	44.4		54.5	28.6
Unknown/indeterminate	33.3		45.5	14.3
Non-smokers	100		100	100
Prestudy vital signs	Mean	SEM
Systolic blood pressure (mmHg)	121.4	2.3	123.8 ± 3.7	115.4 ± 5.5	0.21
Diastolic blood pressure (mmHg)	76.1	1.6	72.1 ± 3.2	71.9 ± 4.7	0.97
Pulse (beats/minute)	72.1	1.9	67.6 ± 2.2	72.7 ± 4.8	0.30
Post-study vital signs	Mean	SEM
Systolic blood pressure (mmHg)	122.4	2.8	122.7 ± 2.2	117.4 ± 6.1	0.37
Diastolic blood pressure (mmHg)	78.5	1.6	77.6 ± 2.4	76.1 ± 3.9	0.74
Pulse (beats/minute)	72.1	1.8	68.6 ± 0.15	72.0 ± 2.4	0.39