Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen of the coronavirus disease 2019 (COVID-19) pandemic, continues to spread worldwide.
In an interesting new study recently published on the pre-print medRxiv* server, a team of researchers in Ecuador and the U.K. found that high altitudes may be linked to improved COVID-19 survival – particularly among patients with no comorbidities.
Less susceptibility to SARS-CoV-2
SARS-CoV-2 first emerged in December 2019 in Wuhan City, China, and has since spread to 192 countries and regions. To date, more than 101 million have been infected, and more than 2.13 million have died.
The disease spreads quickly and behaves unpredictably. However, high-risk groups who are more likely to develop severe symptoms are those who are over 60 years old and those with comorbidities or underlying medical conditions.
Many studies have identified differences in severity of illness and death depending on many factors, such as healthcare access, socioeconomic status, the burden of chronic diseases, the strength of the epidemiological surveillance systems, and infection control measures.
Another unclear association has been between staying in a high altitude area and the severity of COVID-19 illness. It has been proposed that people who live in high altitude areas, where they develop greater tolerance to hypoxia, are more likely to survive COVID-19.
Further, scientists also believe that people in high altitude areas, like mountains, have less susceptibility to SARS-CoV-2 since they have a lower expression of angiotensin-converting enzyme 2 (ACE2) receptors. ACE2 is the means by which the virus latches onto and infiltrates host cells.
The study shows the difference between hospitalized patients staying in high altitude intensive care units (ICUs), than those in low altitude ICUs.
To arrive at the study findings, the researchers compared the clinical course and outcomes of critically ill patients with COVID-19. These patients are hospitalized in two ICUs located at low and high altitudes.
The team aimed to see the effect of two elevations, which were 10 meters and 2,850 meters above sea level, on the clinical outcome and survival of patients diagnosed with COVID-19. They conducted a prospective cohort, two-center study in confirmed COVID-19-positive adult patients admitted to both a low altitude or sea level ICU unit as well as a high altitude one.
The study findings revealed that of the 230 COVID-19 patients, 45.7 percent had at least one underlying health condition such as high blood pressure, diabetes, and chronic kidney failure.
When comparing the two cohorts, the study showed that the low altitude group had a higher number of white blood cells, lower platelets, and higher levels of C-reactive protein, which is present if there is inflammation in the body.
Meanwhile, the oxygenation status was compromised in both groups upon admission. In further examinations, COVID-19 patients manifested dyspnea or difficulty breathing, increased heart rate, and decreased oxygen levels.
In a nutshell, the study findings showed that among critically-ill COVID-19 patients, there was a marked improvement in survival in those situated in high-altitude ICUs. They also had improved severity-of-disease classification system scores at three days from symptom onset. These patients also had better ventilatory and respiratory profiles compared to those in the low-altitude group.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.