Ethnic Differences on Cardiac Rhythms and Autonomic Nervous System Responses During a High-Altitude Trek: A Pilot Study Comparing Italian Trekkers to Nepalese Porters

Frontiers in Physiology

Antonio Crisafulli¹  Danilo Bondi²  Annalisa Chiavaroli³  Claudio Ferrante³  Luigi Brunetti³  Vittore Verratti⁴  Paolo Cerretelli⁵  Alessandro Tonacci⁶ 

[1] Department of Medical Science and Public Health, University of Cagliari, Cagliari, Italy;Department of Neuroscience, Imaging and Clinical Sciences, University “G. d'Annunzio” of Chieti-Pescara, Chieti, Italy;Department of Pharmacy, University “G. d'Annunzio” of Chieti-Pescara, Chieti, Italy;Department of Psychological, Health and Territorial Sciences, University “G. d'Annunzio” of Chieti-Pescara, Chieti, Italy;Institute of Bioimaging and Molecular Physiology, National Research Council of Italy, Segrate, Italy;Institute of Clinical Physiology, National Research Council of Italy, Pisa, Italy;

关键词: heart rate variability;    urinary catecholamines;    himalayas;    altitude hypoxia;    adaptiveness;    blood pressure;   

DOI  :  10.3389/fphys.2021.709451

来源: DOAJ

【 摘 要 】

Altitude hypoxia exposure results in increased sympathetic activity and heart rate due to several mechanisms. Recent studies have contested the validity of heart rate variability (HRV) analysis on sympathetic activity measurement. But the plethora of HRV metrics may provide meaningful insights, particularly if linked with cardiovascular and autonomic nervous system parameters. However, the population-specific nature of HRV and cardiorespiratory response to altitude hypoxia are still missing. Six Italian trekkers and six Nepalese porters completed 300 km of a Himalayan trek. The ECG analysis was conducted at baseline, and before (bBC) and after (aBC) the high-altitude (HA) circuit. Urine was collected before and after the expedition in Italians, for assessing catecholamines. Heart rate increased with altitude significantly (p < 0.001) in the Italian group; systolic (p = 0.030) and diastolic (p = 0.012) blood pressure, and mean arterial pressure (p = 0.004) increased with altitude. Instead, pulse pressure did not change, although the Nepalese group showed lower baseline values than the Italians. As expected, peripheral oxygen saturation decreased with altitude (p < 0.001), independently of the ethnic groups. Nepalese had a higher respiratory rate (p = 0.007), independent of altitude. The cardiac vagal index increased at altitude, from baseline to bBC (p = 0.008). Higuchi fractal dimension (HFD) showed higher basal values in the Nepalese group (p = 0.041), and a tendency for the highest values at bBC. Regarding the urinary catecholamine response, exposure to HA increased urinary levels, particularly of norepinephrine (p = 0.005, d = 1.623). Our findings suggest a better cardiovascular resilience of the Nepalese group when compared with Italians, which might be due to an intrinsic adaptation to HA, resulting from their job.

【 授权许可】

Unknown