Table 2.

HRV Measurements of the Restricted Analytical Sample (those designated as ‘Healthy’), According to Age- and Sex-Related Distribution by Percentiles.

HRV(n = 543)	n	Sex	Age	Percentile						Mean sex-difference(Male – Female)	P-value for sex-related difference
			Years	5th	25th	50th	75th	95th	Mean ± se
SDNN, ms	50	Male	18–30	116	151	177	226	280	187 ± 6	28 ± 4	< 0.001
	54		30–39	114	134	159	190	240	165 ± 6
	43		40–49	98	128	140	188	218	155 ± 7
	43		50–59	85	122	149	180	218	152 ± 7
	35		≥ 60	60	116	136	152	276	140 ± 7
	87	Female	18–30	94	123	143	157	179	140 ± 3
	100		30–39	89	120	137	158	197	139 ± 3
	67		40–49	74	112	126	145	184	128 ± 4
	49		50–59	77	121	136	155	186	136 ± 4
	15		≥ 60	79	90	110	128	179	115 ± 8
SDANN, ms	50	Male	18–30	97	130	153	209	256	167 ± 5	26 ± 3	< 0.001
	54		30–39	87	121	144	172	221	149 ± 5
	43		40–49	81	112	126	171	215	140 ± 5
	43		50–59	71	106	138	163	205	138 ± 5
	35		≥ 60	51	100	120	132	234	121 ± 6
	87	Female	18–30	77	104	125	138	160	122 ± 4
	100		30–39	73	98	120	144	186	122 ± 4
	67		40–49	57	93	111	138	162	114 ± 4
	49		50–59	67	108	127	144	178	126 ± 5
	15		≥ 60	60	77	93	113	152	98 ± 9
rMSSD, ms	50	Male	18–30	27	44	53	81	106	60 ± 3	4 ± 2	0.070
	54		30–39	22	30	40	51	83	43 ± 3
	43		40–49	17	24	32	45	56	34 ± 3
	43		50–59	19	23	30	39	58	33 ± 3
	35		≥ 60	12	22	29	51	153	40 ± 3
	87	Female	18–30	24	34	45	58	78	47 ± 2
	100		30–39	18	29	37	49	80	41 ± 2
	67		40–49	20	25	31	39	64	34 ± 2
	49		50–59	17	21	27	35	67	30 ± 3
	15		≥ 60	16	25	29	36	105	40 ± 5
pNN50, %	50	Male	18–30	5	13	22	33	46	23 ± 1	2 ± 1	0.017
	54		30–39	2	6	9	19	32	13 ± 1
	43		40–49	1	3	6	12	20	8 ± 1
	43		50–59	1	3	5	9	17	7 ± 1
	35		≥ 60	0.25	1	3	7	38	7 ± 2
	87	Female	18–30	4	10	15	21	32	16 ± 1
	100		30–39	1	5	11	18	35	13 ± 1
	67		40–49	1	3	7	12	31	9 ± 1
	49		50–59	0.50	2	3	7	14	5 ± 1
	15		≥ 60	1	1	4	6	13	5 ± 2

‘Healthy’ sample excluded those under medication use, those who had HTN, DM, obesity, current smokers, past stroke, past AMI, cancer, cardiac revascularization or angioplasty (see Appendix Figure A1). Male (n = 225) and Female (n = 318). se = standard error; HTN = hypertension; DM = diabetes mellitus; AMI = acute myocardium infarction; NN = normal-to-normal; SDNN = standard deviation of NN intervals; SDANN = standard deviation of the average of all consecutive 5-minute NN intervals; rMSSD = root mean square of successive difference of NN intervals; pNN50 = percentage of consecutive NN intervals that deviate from one another by more than 50 ms.