Impact of High Altitude on Cardiovascular Health: Current Perspectives

Abstract

Globally, about 400 million people reside at terrestrial altitudes above 1500 m, and more than 100 million lowlanders visit mountainous areas above 2500 m annually. The interactions between the low barometric pressure and partial pressure of O 2 , climate, individual genetic, lifestyle and socio-economic factors, as well as adaptation and acclimatization processes at high elevations are extremely complex. It is challenging to decipher the effects of these myriad factors on the cardiovascular health in high altitude residents, and even more so in those ascending to high altitudes with or without preexisting diseases. This review aims to interpret epidemiological observations in high-altitude populations; present and discuss cardiovascular responses to acute and subacute high-altitude exposure in general and more specifically in people with preexisting cardiovascular diseases; the relations between cardiovascular pathologies and neurodegenerative diseases at altitude; the effects of high-altitude exercise; and the putative cardioprotective mechanisms of hypobaric hypoxia.

The Effects of Sodium Phosphate Supplementation on the Cardiorespiratory System and Gross Efficiency during Exercise under Hypoxia in Male Cyclists: A Randomized, Placebo-Controlled, Cross-Over Study

“…In contrast, maximal HR and SV are lowered and thus maximal Q declines in hypoxic conditions [21]. During submaximal exercise, at a given exercise intensity (at the same absolute workload), HR is greater and SV is lower in hypoxia compared to normoxia [19,20,22]. For example, Clark et al [23] found that submaximal HR during 50-250 W workloads was significantly elevated by a mean of 5-21 bpm at both 2200 m and 3200 m compared to sea level.…”

Association between Altitude and the Framingham Risk Score: A Cross-Sectional Study in the Peruvian Adult Population

“…This finding could be attributed to the fact that people residing in high-altitude regions develop protective mechanisms against hypobaric hypoxia from birth and have a lower tendency of developing hypertension and having conventional blood pressure measurements that may underestimate the prevalence of hypertension in this population [ 12 , 45 ]. In addition, this population experiences low levels of urbanization, low income, and healthier lifestyles (more physical activity and lower fat consumption) compared to people living in low-altitude regions [ 46 , 47 , 48 ], thereby producing a lower prevalence of coronary risk factors.…”

Effects of Intermittent Hypoxia-Hyperoxia Exposure Prior to Aerobic Cycling Exercise on Physical and Cognitive Performance in Geriatric Patients—A Randomized Controlled Trial

“…Studies have further found that the mitochondria respiratory chain is one of the main intracellular sources of reactive oxygen species (e.g., hydrogen peroxide [H 2 O 2 ]) in human cells, which are generated in response to the incomplete electron reduction of molecular oxygen ( Murphy, 2009 ; Bae et al, 2011 ). Reactive oxygen species disrupt the link between Nrf2 and its repressor Kelch-like ECH-associated protein 1, thus releasing Nrf2 to enter the nucleus, where it triggers intracellular redox signalling cascades, which activate, among others, antioxidant and anti-inflammatory genes ( Sazontova et al, 2012 ; Burtscher et al, 2021 ; Mallet et al, 2021 ). Although the exact molecular mechanisms triggered by IHHE are not fully understood, reactive oxygen species-induced signalling pathways are thought to be enhanced when hypoxia and hyperoxia alternate in place of normoxia ( Sazontova et al, 2012 ; Burtscher et al, 2021 ).…”