20.500.12556/RUL-164611 Ventilatory responses to independent and combined hypoxia, hypercapnia and hypobaria in healthy pre-term-born adults 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. altitude chemosensitivity hypercapnia hypobaria hypoxia prematurity ventilation true false true Angleški jezik Ni določen Članek v reviji 2024-11-05 13:38:53 2024-11-05 13:38:54 2024-11-22 14:55:02 0000-00-00 00:00:00 2024 0 0 Str. 5943–5958 iss. 21 Vol. 602 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 612 0022-3751 10.1113/JP285300 167257091 The_Journal_of_Physiology_-_2023_-_Narang_-_Ventilatory_responses_to_independent_and_combined_hypoxia__hypercapnia_and.pdf The_Journal_of_Physiology_-_2023_-_Narang_-_Ventilatory_responses_to_independent_and_combined_hypoxia__hypercapnia_and.pdf 1 3EA391CACD574C6A76D38C24C4DEC378 8023d27cf3bfdecbe82157aef1223b6a5a3b7644d22b80e88b1103d0f83e7501 f8ce330a-9b72-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=195167 https://physoc.onlinelibrary.wiley.com/doi/10.1113/JP285300 0 d7bc23d7-9b72-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=195165 Fakulteta za šport 0 0 0