Table 4.

TSH concentrations (mU/L) at different altitude levels in the whole group of subjects and differences relative to PR.

	Mean ± s.d.	N	Differences relative to Pr (adjusted for paO2)
			Coefficient ± s.e.	P value	95% CI
PR	2.15 ± 1.33	38
BC1	2.27 ± 1.22	38	0.07 ± 0.10	0.471	−0.13; 0.28
C2	2.20 ± 1.26	30	0.03 ± 0.11	0.770	−0.18; 0.25
C3	3.46 ± 2.88	13	1.08 ± 0.15	<0.001	0.79; 1.38
BC2	2.28 ± 1.43	27	0.08 ± 0.11	0.471	−0.14; 0.31
PO	1.93 ± 1.09	37	−0.20 ± 0.10	0.055	−0.40; 0.01

Variation of TSH was not sex and SaO₂ but PaO₂ (P = 0.011) dependent.

Altitudes: PR, Pre expedition = 550 m; BC1, Base Camp 1 = 4.844 m; C2, Camp2 = 6022 m; BC2, Base Camp 2 (after acclimatization) = 4.844 m; C3, Camp3 = 7050 m; PO, Post expedition = 550 m.