Peripheral chemoresponsiveness during exercise in male athletes with exercise-induced arterial hypoxaemia.
Exp Physiol
; 105(11): 1960-1970, 2020 11.
Article
em En
| MEDLINE
| ID: mdl-32857874
ABSTRACT
NEW FINDINGS:
What is the central question of this study? Do highly trained male endurance athletes who develop exercise-induced arterial hypoxaemia (EIAH) demonstrate reduced peripheral chemoresponsiveness during exercise? What is the main finding and its importance? Those with the lowest arterial saturation during exercise have a smaller ventilatory response to hypercapnia during exercise. There was no significant relationship between the hyperoxic ventilatory response and EIAH. The findings suggest that peripheral chemoresponsiveness to hypercapnia during exercise could play a role in the development of EIAH. The findings improve our understanding of the mechanisms that contribute to EIAH. ABSTRACT Exercise-induced arterial hypoxaemia (EIAH) is characterized by a decrease in arterial oxygen tension and/or saturation during whole-body exercise, which may in part result from inadequate alveolar ventilation. However, the role of peripheral chemoresponsiveness in the development of EIAH is not well established. We hypothesized that those with the most severe EIAH would have an attenuated ventilatory response to hyperoxia and hypercapnia during exercise. To evaluate this, on separate days, we measured ventilatory sensitivity to hyperoxia and separately hypercapnia at rest and during three different exercise intensities (25, 50% of VÌO2max and ventilatory threshold (â¼67% of VÌO2max )) in 12 males cyclists ( VÌO2max = 66.6 ± 4.7 ml kg-1 min-1 ). Subjects were divided into two groups based on their end-exercise arterial oxygen saturation (ear oximetry, SpO2 ) a normal oxyhaemoglobin saturation group (NOS, SpO2 = 93.4 ± 0.4%, n = 5) and a low oxyhaemoglobin saturation group (LOS, SpO2 = 89.9 ± 0.9%, n = 7). There was no difference in VÌO2max (66.4 ± 2.9 vs. 66.8 ± 6.0 ml kg-1 min-1 , respectively, P = 0.9), peak ventilation during maximal exercise (182 ± 15 vs. 197 ± 32 l min-1 , respectively, P = 0.36) or ventilatory response to hyperoxia (P = 0.98) at any exercise intensity between NOS and LOS groups. However, those in the LOS group had a significantly lower ventilatory response to hypercapnia (P = 0.004, (η2 = 0.18). There was also a significant relationship between the mean hypercapnic response and end-exercise SpO2 (r = 0.75, P = 0.009) but not between the mean hyperoxic response and end-exercise SpO2 (r = 0.21, P = 0.51). A blunted hypercapnic ventilatory response may contribute to EIAH in highly trained men due to a failure to increase ventilation sufficiently to offset exercise-induced gas exchange impairments.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Consumo de Oxigênio
/
Exercício Físico
Limite:
Humans
/
Male
Idioma:
En
Revista:
Exp Physiol
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Canadá