. 2022 Nov 23;13:1062397. doi: 10.3389/fphys.2022.1062397

TABLE 4.

Binary logistic regression models of individual self-reported hypoxia-related symptoms.

	Model 1			Model 2
	OR	95% CI	p	OR	95% CI	p
Tingling
Sex	0.59	(0.25, 1.40)	0.24	0.64	(0.26, 1.60)	0.34
Age	1.03	(1.00, 1.10)	0.45	1.03	(0.96, 1.11)	0.40
BMI	1.05	(0.94, 1.17)	0.40	1.05	(0.93, 1.18)	0.48
Altitude (k) ^a				1.37	(1.15, 1.63)	0.01^**
Exposure (min)				1.05	(0.98, 1.12)	0.18
Hot flashes
Sex	1.44	(0.56, 3.71)	0.45	1.27	(0.45, 3.57)	0.65
Age ^b	1.12	(1.03, 1.21)	0.01^**	1.12	(1.03, 1.23)	0.01^**
BMI	0.97	(0.85, 1.11)	0.67	0.97	(0.84, 1.11)	0.65
Altitude (k)				1.21	(1.00, 1.48)	0.05
Exposure (min) ^c				0.91	(0.83, 0.99)	0.03^*
Dizziness
Sex	2.13	(0.93, 4.86)	0.07	2.47	(0.93, 6.57)	0.07
Age	1.02	(0.95, 1.09)	0.65	1.03	(0.95, 1.11)	0.52
BMI	1.00	(0.90, 1.13)	0.94	1.00	(0.88, 1.14)	0.99
Altitude (k) ^d				1.55	(1.27, 1.89)	0.01^**
Exposure (min)				0.95	(0.87, 1.03)	0.22
Tunnel vision
Sex	1.22	(0.54, 2.75)	0.64	1.22	(0.52, 2.87)	0.65
Age	1.00	(0.94, 1.07)	0.98	1.00	(0.94, 1.07)	0.97
BMI	0.91	(0.81, 1.02)	0.17	0.91	0.81, 1.02)	0.100
Altitude (k) ^e				1.19	(1.01, 1.39)	0.04^*
Exposure (min)				1.00	(0.94, 1.07)	0.98
Light dimming
Sex	0.85	(0.32, 2.23)	0.73	0.86	(0.32, 2.31)	0.76
Age	1.08	(1.00, 1.17)	0.05	1.08	(1.00, 1.16)	0.05
BMI	0.94	(0.82, 1.07)	0.33	0.93	(0.93, 0.86)	0.31
Altitude (k)				1.08	(0.90, 1.29)	0.40
Exposure (min)				1.00	(0.93, 1.08)	0.93
Euphoria
Sex	0.53	(0.13, 2.08)	0.36	0.69	(0.17, 2.84)	0.61
Age	1.01	(0.91, 1.12)	0.85	1.01	(0.91, 1.12)	0.86
BMI	0.90	(0.75, 1.08)	0.25	0.88	(0.73, 1.07)	0.20
Altitude (k)				1.05	(0.82, 1.35)	0.68
Exposure (min)				1.11	(0.99, 1.25)	0.07
Loss of coordination
Sex	1.12	(0.42, 2.94)	0.83	1.45	(0.44, 4.79)	0.54
Age	1.02	(0.95, 1.11)	0.95	1.05	(0.95, 1.15)	0.40
BMI	0.99	(0.87, 1.13)	0.87	0.96	(0.82, 1.17)	0.57
Altitude (k) ^f				1.71	(1.37, 2.12	0.01^**
Exposure (min)				1.01	(0.91, 1.12)	0.88
Headache
Sex ^g	2.69	(1.04, 7.00)	0.04^*	3.33	(1.18, 9.43)	0.02^*
Age ^h	0.90	(0.83, 0.99)	0.03^*	0.90	(0.82, 0.99)	0.02^*
BMI	1.03	(0.90, 1.17)	0.68	1.02	(0.90, 1.17)	0.73
Headache
Altitude (k) ⁱ				1.28	(1.06, 1.54)	0.01^**
Exposure (min)				1.05	(0.97, 1.15)	0.24
Fatigue
Sex	1.11	(0.50, 2.48)	0.80	0.98	(0.43, 2.26)	0.96
Age ^j	0.93	(0.87, 0.99)	0.03^*	0.92	(0.86, 0.99)	0.02^*
BMI	0.14	(097, 1.21)	0.14	1.10	(0.98, 1.23)	0.10
Altitude (k)				0.84	(0.71, 1.00)	0.05
Exposure (min)				0.95	(0.89, 1.01)	0.10
Breathlessness
Sex	1.78	(0.78, 4.04)	0.17	1.76	(0.75, 4.13)	0.19
Age	1.03	(0.96, 1.10)	0.50	1.03	(0.96, 1.10)	0.45
BMI	1.08	(0.97, 1.21)	0.16	1.09	(0.97, 1.22)	0.16
Altitude (k) ^k				1.18	(1.01, 1.40)	0.04^*
Exposure (min)				0.98	(0.02, 105)	0.57
Blurred vision
Sex	1.07	(0.47, 2.45)	0.88	1.07	(0.46, 2.50)	0.88
Age	1.00	(0.94, 1.08)	0.92	1.00	(0.94, 1.08)	0.91
BMI	0.89	(0.79, 1.01)	0.06	0.89	(0.79, 1.00)	0.06
Altitude (k)				1.05	(0.89, 1.24)	0.57
Exposure (min)				1.00	(0.94, 1.07)	0.96
Nausea
Sex	1.26	(0.42, 3.80)	0.68	1.32	(0.43, 4.08)	0.63
Age	1.05	(0.95, 1.15)	0.35	1.05	(0.95, 1.15)	0.36
BMI	1.12	(0.97, 1.29)	0.13	1.11	(0.96, 1.29)	0.15
Altitude (k)				1.10	(0.90, 1.35)	0.37
Exposure (min)				1.00	(0.92, 1.09)	0.95
Apprehension
Sex	2.06	(0.79, 5.39)	0.14	3.20	(0.98, 10.40)	0.05
Age	0.99	(0.91, 1.08)	0.80	0.99	(0.90, 1.09)	0.88
BMI	1.07	(0.94, 1.21)	0.34	1.07	(0.92, 1.23)	0.40
Altitude (k) ^l				1.59	(1.29, 1.60)	0.01^**
Exposure (min)				1.02	(0.92, 1.13)	0.71

Note. Abbreviations (OR, odds ratio; CI, confidence interval; BMI, body mass index). Male reference value for sex.

^{^a}

Altitude significantly associated with increased reports of tingling, p < .001.

^{^b}

Age significantly associated with increased reports of hot flashes, p = .01.

^{^c}

Exposure minutes significantly associated with decreased reports of hot flashes, p = .03.

Altitude significantly associated with increased reports of dizziness, p < .001.

^{^e}

Altitude significantly associated with increased reports of tunnel vision, p = .04.

^{^f}

Altitude significantly associated with increased reports of loss of coordination, p < .001.

^{^g}

Female sex significantly associated with increased reports of headache, p = .02.

^hAge significantly associated with increased reports of headache, p = .02.

^ⁱ

Altitude significantly associated with increased reports of headache, p = .01.

^{^j}

Age significantly associated with increased reports of fatigue, p = .02.

^{^k}

Altitude significantly associated with increased reports of breathlessness, p = .04.

^{^l}

Altitude significantly associated with increased reports of apprehension, p < .001.^** p < .01.^* p < .05.