Table 2.

Changes of the intrinsic cardiovascular regulatory system β during 6-month space flight in each astronaut classified into Group A or B.

Case	Pre		ISS01		ISS02		ISS03		ISS02 vs. ISS01		ISS03 vs. ISS01		ISS03 vs. ISS02
	Mean	SE	Mean	SE	Mean	SE	Mean	SE	t	p	t	p	t	p
	Group A: B2-band response (+)
	LF-band response (+)
1	−1.0584	0.0275	−1.0564	0.0213	−0.8186	0.0150	−0.9728	0.0140	9.14	<0.0001	3.28	0.0111	−7.53	<0.0001
2	−1.1645	0.0199	−0.9698	0.0123	−1.1248	0.0171	−0.9050	0.0075	−7.34	<0.0001	4.48	0.0001	11.73	<0.0001
3	−1.3017	0.0205	−0.8700	0.0144	−0.7900	0.0267	−0.8832	0.0173	2.64	0.0843	−0.59	0.9997	−2.93	0.0356
4	−1.1761	0.0157	−1.0009	0.0121	−0.9159	0.0139	−1.0134	0.0191	4.61	0.0001	−0.55	0.9998	−4.13	0.0004
	Group B: B2-band response (−)
	Group B1: LF-band response (+)
5	−1.0258	0.0140	−0.8483	0.0232	−0.6810	0.0192	−0.7753	0.0292	5.55	<0.0001	1.96	0.4082	−2.70	0.0699
6	−1.2171	0.0140	−1.1413	0.0209	−1.0638	0.0116	−1.0722	0.0182	3.25	0.0126	2.50	0.1212	−0.39	1.0000
	Group B2: LF-band response (−)
7	−1.0698	0.0267	−0.8535	0.0242	−0.9988	0.0260	−0.9741	0.0258	−4.09	0.0005	−3.41	0.0071	0.68	0.9990
8	−0.9864	0.0270	−1.0370	0.0228	−0.8830	0.0147	−0.8484	0.0249	5.67	<0.0001	5.58	<0.0001	1.19	0.9303

B2-band: HRV-SFO; LF-band: HRV-VSFO.

N between 230 and 255; t: Student t; p: P-value (Sidak correction).