Urine acid-base compensation at simulated moderate altitude

Ri Li Ge, Tony G. Babb, Mark Sivieri, Geir K. Resaland, Trine Karlsen, Jim Stray-Gundersen, Benjamin D. Levine

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Acute exposure to high altitude elicits respiratory alkalosis, and this is partially corrected by renal compensation. To determine the time course and magnitude of renal compensation during short-term moderate altitude exposure, we measured urine gas tensions and acid-base status in 48 healthy men and women at four levels of simulated altitude exposures. Each subject was exposed in pseudorandom order to simulated altitudes of 1780, 2085, 2455, and 2800 m. in a decompression chamber for 24 h, separated by 1 week at sea level. Fresh urine was collected anaerobically at sea level and after 6 and 24 h of each altitude exposure. Urine pH increased significantly (p < 0.01) after 6 h at all altitudes and returned to baseline values by 24 h at the lowest altitudes. In contrast, urine pH remained elevated at the highest altitudes. The mean value of urine HCO3 - at sea level was 1.67 ± 0.25 mmol/L, increased significantly after 6 h at all altitudes, and then returned to near baseline after 24 h at three lower altitudes (1780, 2085, and 2455 m). However, it remained elevated at 2800 m. PCO2 in urine was significantly increased after 6 h and returned to baseline after 24 h at all altitudes. These results suggest that (1) short-term low to moderate altitude exposure results in a marked HCO3 - diuresis, which may be caused by inhibition of the secretion of renal tubular H+, and (2) renal HCO3 - compensation was completed by 24 h at low to moderate altitude, but still incomplete at higher altitude.

Original languageEnglish (US)
Pages (from-to)64-71
Number of pages8
JournalHigh Altitude Medicine and Biology
Volume7
Issue number1
DOIs
StatePublished - Mar 2006

Fingerprint

Urine
Acids
Oceans and Seas
Kidney
Respiratory Alkalosis
Diuresis
Decompression
Gases

Keywords

  • Acclimatization
  • Decompression chamber
  • High altitude
  • Renal HCO
  • Sa

ASJC Scopus subject areas

  • Medicine(all)
  • Physiology
  • Physical Therapy, Sports Therapy and Rehabilitation
  • Orthopedics and Sports Medicine

Cite this

Urine acid-base compensation at simulated moderate altitude. / Ge, Ri Li; Babb, Tony G.; Sivieri, Mark; Resaland, Geir K.; Karlsen, Trine; Stray-Gundersen, Jim; Levine, Benjamin D.

In: High Altitude Medicine and Biology, Vol. 7, No. 1, 03.2006, p. 64-71.

Research output: Contribution to journalArticle

Ge, RL, Babb, TG, Sivieri, M, Resaland, GK, Karlsen, T, Stray-Gundersen, J & Levine, BD 2006, 'Urine acid-base compensation at simulated moderate altitude', High Altitude Medicine and Biology, vol. 7, no. 1, pp. 64-71. https://doi.org/10.1089/ham.2006.7.64
Ge, Ri Li ; Babb, Tony G. ; Sivieri, Mark ; Resaland, Geir K. ; Karlsen, Trine ; Stray-Gundersen, Jim ; Levine, Benjamin D. / Urine acid-base compensation at simulated moderate altitude. In: High Altitude Medicine and Biology. 2006 ; Vol. 7, No. 1. pp. 64-71.
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