A systematic review evaluating intermittent exposure of workers to hypoxic conditions and the prevalence of certain types of cardiovascular diseases is published in the BMJ Open.
The researchers reviewed 17 studies of irregular short-term intermittent hypoxia and 14 studies of long-term intermittent hypoxia. These publications included adult workers repeatedly subjected to months to years of irregular intermittent hypoxia, lasting from a few hours (e.g., flight crews), one or a few days (e.g., soldiers), or several days to weeks (e.g., miners working at high altitude).
They found that the population of irregular short-term intermittent hypoxia (flight crew) showed a lower mortality for cardiovascular disease. On the other hand, long-term intermittent hypoxia over several years such as in miners or soldiers had increased levels of cardiac disorders, although this was probably confounded by factors such as obesity and socioeconomic status.
This systematic narrative review demonstrates that mortality from cardiovascular diseases in a population with irregular short-term intermittent hypoxia is not higher than average in a comparable population, but individuals exposed to more severe long-term intermittent hypoxia appear to suffer an increased risk of cardiac disorders, the authors conclude.