Table 5.

Transfer function analysis metrics in older adults for the relationship between mean arterial pressure and cerebral blood flow at rest and during moderate exercise

	Rest	Exercise
Spontaneous Oscillations
VLF MAP power, mmHg2	4.86 ± 3.16	8.58 ± 17.30
LF MAP power, mmHg2	1.98 ± 1.04	2.31 ± 1.76
VLF MCAv power, (cm/s)2	7.95 ± 6.36	4.54 ± 2.76
LF MCAv power, (cm/s)2	1.83 ± 0.72	2.11 ± 1.53
VLF coherence	0.37 ± 0.13	0.40 ± 0.11
LF coherence	0.61 ± 0.18	0.48 ± 0.19
VLF phase, radians	1.03 ± 0.45	1.47 ± 0.48
LF phase, radians	0.62 ± 0.24	0.70 ± 0.19
VLF gain, cm·s−1·mmHg−1	1.05 ± 0.54	0.95 ± 0.54
LF gain, cm·s−1·mmHg−1	1.08 ± 0.35	0.99 ± 0.47
VLF gain, %/%	1.90 ± 1.08	1.89 ± 1.44
LF gain, %/%	1.92 ± 0.49	1.74 ± 0.74
Driven Oscillations
0.05 Hz MAP power, mmHg2/Hz	1,845 ± 2,178*	7,685 ± 7,247*‡
0.10 Hz MAP power, mmHg2/Hz	1,311 ± 2,087†	4,616 ± 3,169†‡
0.05 Hz MCAv power, (cm/s)2/Hz	722 ± 1,070*	1,668 ± 1,114*‡
0.10 Hz MCAv power, (cm/s)2/Hz	786 ± 1,370†	3,665 ± 2,501†‡
0.05 Hz coherence	0.90 ± 0.10*	0.98 ± 0.02*‡
0.10 Hz coherence	0.89 ± 0.13†	0.98 ± 0.02†‡
0.05 Hz phase, radians	0.99 ± 0.35	1.35 ± 0.32‡
0.10 Hz phase, radians	0.68 ± 0.41	0.46 ± 0.27†‡
0.05 Hz gain, cm·s−1·mmHg−1	0.61 ± 0.15*	0.59 ± 0.24*
0.10 Hz gain, cm·s−1·mmHg−1	0.76 ± 0.45	0.91 ± 0.27
0.05 Hz gain, %/%	1.07 ± 0.32*	1.11 ± 0.44*
0.10 Hz gain %/%	1.32 ± 0.75	1.64 ± 0.54

Values are means ± SD.

MAP, mean arterial pressure; MCAv, middle cerebral artery velocity; LF, low frequency; VLF, very low frequency.

Statistical significance was set at P < 0.05.

^*Significantly different from VLF;

^†significantly different from LF;

^‡significantly different from rest.