Gender Differences in Age-Related Changes in Cardiac Autonomic Nervous Function

Table 2

Comparison of heart rate variability spectral power (absolute power) in males and females of different age groups (𝑛=252).

	Children	Adolescent	Young adults	Middle-aged
Total power (0–0.4 Hz) (ms^2)
Males	2694±336	2072±306	1171±212	563±121
	(2006–3381)	(1446–2697)	(736–1606)	(313–814)
Females	2433±331	1612±246	1148±149	478±82
	(1756–3110)	(1112–2112)	(846–1456)	(308–448)
Total	2564 ± 234	1822 ± 194	1158 ± 124^*†	520 ± 72^*†‡
	(2094–3033)	(1434–2209)	(909–1407)	(375–665)
Two-way ANOVA: 𝑃<0.001 between age groups, 𝑃=0.420 between genders, and 𝑃=0.379 for interaction between age and gender.
High-frequency power (0.15–0.4 Hz) (ms^2)
Males	1645 ± 209	1057 ± 165	533 ± 98	238 ± 56
	(1215–2074)	(720–1394)	(331–734)	(121–355)
Females	1561 ± 254	999 ± 155	628 ± 98	209 ± 56
	(1040–2082)	(683–1314)	(427–825)	(128–289)
Total	1603 ± 163	1025 ± 112	585 ± 69^*†	223 ± 34^*†‡
	(1250–1931)	(801–1275)	(446–724)	(155–291)
Two-way ANOVA: 𝑃<0.001 between age groups, 𝑃=0.995 between genders, and 𝑃=0.592 for interaction between age and gender.
Low-frequency power (0.04–0.15 Hz) (ms^2)
Males	1049 ± 148	1001 ± 187	638 ± 118	325 ± 66
	(745–1352)	(619–1384)	(396–879)	(188–461)
Females	872 ± 108	584 ± 111	522 ± 71	269 ± 45
	(650–1093)	(357–812)	(377–666)	(175–363)
Total	960 ± 92	760 ± 103	573 ± 65^*†	296 ± 39^*†‡
	(776–1144)	(583–997)	(442–703)	(217–376)
Two-way ANOVA: 𝑃<0.001 between age groups, 𝑃=0.034 between genders, and 𝑃=0.234 for interaction between age and gender.

Data expressed as mean ± SEM and 95% Confidence Intervals.
*Significantly different from children group.
^†Significantly different from adolescent age group.
^‡Significantly different from adult group.
^#Significantly different from females of same age group.
^≠Age × Gender = age and gender interaction.