Ventilatory responses to independent and combined hypoxia, hypercapnia and hypobaria in healthy pre-term-born adults

Narang, Benjamin J. (avtor), Manferdelli, Giorgio (avtor), Bourdillon, Nicolas (avtor), Millet, Grégoire P. (avtor), Debevec, Tadej (avtor)

Pre-term birth is associated with physiological sequelae that persist into adulthood. In particular, modulated ventilatory responsiveness to hypoxia and hypercapnia has been observed in this population. Whether pre-term birth per se causes these effects remains unclear. Therefore, we aimed to assess pulmonary ventilation and blood gases under various environmental conditions, comparing 17 healthy prematurely born individuals (mean ± SD; gestational age, 28 ± 2 weeks; age, 21 ± 4 years; peak oxygen uptake, 48.1 ± 11.2 ml kg$^{−1}$ min$^{−1}$) with 16 well-matched adults born at term (gestational age, 40 ± 1 weeks; age, 22 ± 2 years; peak oxygen uptake, 51.2 ± 7.7 ml kg$^{−1}$ min$^{−1}$). Participants were exposed to seven combinations of hypoxia/hypobaria (equivalent to ∼3375 m) and/or hypercapnia (3% CO$_2$), at rest for 6 min. Pulmonary ventilation, pulse oxygen saturation and the arterial partial pressures of O$_2$ and CO$_2$ were similar in pre-term and full-term individuals under all conditions. Higher ventilation in hypoxia compared to normoxia was only observed at terrestrial altitude, despite an equivalent (normobaric) hypoxic stimulus administered at sea level (0.138 F$_{iO_2}$). Assessment of oscillations in key variables revealed that combined hypoxic hypercapnia induced greater underlying fluctuations in ventilation in pre-term individuals only. In general, higher pulse oxygen saturation fluctuations were observed with hypoxia, and lower fluctuations in end-tidal CO$_2$ with hypercapnia, despite similar ventilatory oscillations observed between conditions. These findings suggest that healthy prematurely born adults display similar overall ventilation to their term-born counterparts under various environmental stressors, but that combined ventilatory stimuli could induce an irregular underlying ventilatory pattern. Moreover, barometric pressure may be an important factor when assessing ventilatory responsiveness to moderate hypoxic stimuli.

• Jezik: Angleški jezik
• Ključne besede: altitude, chemosensitivity, hypercapnia, hypobaria, hypoxia, prematurity, ventilation
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FŠ - Fakulteta za šport
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2024
• Št. strani: Str. 5943–5958
• Številčenje: Vol. 602, iss. 21
• PID: 20.500.12556/RUL-164611
• UDK: 612
• ISSN pri članku: 0022-3751
• DOI: 10.1113/JP285300
• COBISS.SI-ID: 167257091
• Datum objave v RUL: 05.11.2024

Gradivo je del revije

• Naslov: The journal of physiology
• Skrajšan naslov: J. physiol.
• Založnik: Wiley, The Physiological Society
• ISSN: 0022-3751
• COBISS.SI-ID: 1582095

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Projekti

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: N5-0152
• Naslov: Mehanizmi hipoksične (in)tolerance pri predčasno rojenih posameznikih

• Financer: SNSF - Swiss National Science Foundation
• Številka projekta: 320030L_192 073