Table 4.

Potassium, serum osmolality and aldosterone synthase (mean ± SD) for the terrestrial high altitude group.

	Baseline	4600 m	5140 m
Potassium (mmol/L)	4.16 ± 0.24	4.16 ± 0.28	3.96 ± 0.44
Serum osmolality (mOsm/kg)	289 ± 4	357 ± 153	477 ± 185
Aldosterone synthase (ng/mL)	3.21 ± 0.37	3.55 ± 0.30*	3.20 ± 0.28*

Collected at sea level baseline (n = 8) and on expedition, collected the morning of the day after arrival at Dhaulagiri lower base camp (4600 m) on day 10 (n = 8) and at Hidden valley (5140 m) on day 12 (n = 8). * = significantly different to previous altitude.