Does intermittent exposure to high altitude increase the risk of cardiovascular disease in workers? A systematic narrative review
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Aragón Vela, Jerónimo; Bejder, Jacob; Rodríguez Huertas, Jesús Francisco; Plaza Díaz, Julio; Nordsborg, Nikolai BEditorial
Bmj Publishing Group
Date
2020-11-01Referencia bibliográfica
Aragón-Vela, J., Bejder, J., Huertas, J. R., Plaza-Diaz, J., & Nordsborg, N. B. (2020). Does intermittent exposure to high altitude increase the risk of cardiovascular disease in workers? A systematic narrative review. BMJ open, 10(11), e041532. [doi:10.1136/bmjopen-2020-041532]
Sponsorship
Fundación Alfonso Martin Escudero' (Spain)Abstract
Objective Several working groups (eg, miners, flight
crews and soldiers) are subjected to chronic intermittent
hypoxic exposure. The cardiovascular implications have
been studied but not systematically reviewed with focus
on possible negative health implications. The aim of
the present review was to systematically evaluate the
hypothesis that intermittent hypoxic exposure causes
cardiovascular stress detrimental to health in workers.
Design Systematic review.
Data sources Electronic database search of PubMed,
Scopus and Web of Science up to April 2020.
Eligibility criteria Studies of workers ≥18 years
repeatedly subjected to months to years of irregular
intermittent hypoxia, lasting from a few hours (eg, flight
crews), one or a few days (eg, soldiers), or several days
to weeks (eg, miners working at high altitude), written in
English and evaluating the effect of intermittent hypoxia
on cardiovascular disease were included. Animal studies,
books, book chapters, personal communication and
abstracts were excluded. The primary outcome measure
was changes in standardised mortality ratio.
Data extraction and synthesis Two independent
reviewers extracted data and assessed risk of bias using
the Cochrane Collaboration’s tool.
Results 119 articles were identified initially, 31 of which
met the inclusion criteria. Of these, 17 were retrospective
cohort mortality studies (irregular short-term
intermittent
hypoxia), and 14 studies were observational (long-term
intermittent hypoxia). The population of irregular
short-term
intermittent hypoxia users (flight crew)
showed a lower mortality by cardiovascular disease.
Long-term
intermittent hypoxia over several years
such as in miners or soldiers may produce increased
levels of cardiac disorders (12 studies), though this is
probably confounded by factors such as obesity and
socioeconomic status.
Conclusion This systematic narrative review found that
cardiovascular disease mortality in flight crews is lower
than average, whereas miners and soldiers exposed
to intermittent hypoxia experience increased risks of
cardiovascular diseases. The impact of socioeconomic
status and lifestyle appears of importance.