We tested the hypothesis that the individual ventilatory adaptation to high altitude (HA, 5050 m) may influence renal water excretion in response to water loading. In 8 healthy humans (33 ± 4 S.D. years) we studied, at sea level (SL) and at HA, resting ventilation (over(V, ̇)E), arterial oxygen saturation (S pO2), urinary output after water loading (WL, 20 mL/kg), and total body water (TBW). Ventilatory response to HA was defined as the difference in resting over(V, ̇)E over S pO2 (Δ over(V, ̇)E / Δ S pO2) from SL to HA. At HA, a significant increase in urinary volume after the first hour from WL (%WLt(0-60)) was observed. Significant correlations were found between Δ over(V, ̇)E / Δ S pO2 versus %WLt(0-60) at HA and versus changes in TBW, from SL to HA. In conclusion, in healthy subjects the ventilatory response to HA influences water balance and correlates with kidney response to WL. A higher ventilatory response at HA, allowing a more efficient water renal handling, is likely to be a protective mechanisms from altitude illness.
- Water excretion
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine