High-normal blood pressure is associated with increased resting sympathetic activity but normal responses to stress tests

Figures & data

Figure 1. Baseline muscle sympathetic nerve activity (MSNA) in subjects with optimal and high-normal blood pressure (BP) as expressed as bursts/min (a) and bursts/100 heartbeats (a). Values are means± SEM.

Table I. Resting blood pressure (BP) and heart rate in subjects with optimal and high-normal BP.

Measurement	Optimal BP	High-normal BP	p
SBP (mmHg)	116 ± 2	138 ± 2	< 0.001
DBP (mmHg)	74 ± 1	83 ± 2	0.002
HR (beats/min)	70 ± 3	67 ± 3	0.54

Values are means± SEM. SBP, systolic BP; DBP, diastolic BP; HR, heart rate.

Table II. Systolic blood pressure (BP), heart rate and MSNA responses to handgrip and mental stress tests in subjects with optimal and high-normal BP.

Measurement	Optimal BP	High-normal BP	p
Handgrip test
ΔSBP (mmHg)	9.2 ± 2.7	9.6 ± 1.8	0.90
ΔHR (beats/min)	4.0 ± 0.8	6.1 ± 1.2	0.14
ΔMSNA (%)	49 ± 15	37 ± 14	0.55
Mental stress
ΔSBP (mmHg)	5.8 ± 2.1	3.5 ± 1.5	0.37
ΔHR (beats/min)	6.0 ± 1.8	8.3 ± 2.1	0.45
ΔMSNA (%)	37 ± 12	50 ± 28	0.73

Values are means± SEM. SBP, systolic BP; HR, heart rate; MSNA, muscle sympathetic nerve activity.