Therapeutic potential of intermittent hypoxia: a matter of dose

Am J Physiol Regul Integr Comp Physiol. 2014 Nov 15;307(10):R1181-97. doi: 10.1152/ajpregu.00208.2014. Epub 2014 Sep 17.


Intermittent hypoxia (IH) has been the subject of considerable research in recent years, and triggers a bewildering array of both detrimental and beneficial effects in multiple physiological systems. Here, we review the extensive literature concerning IH and its impact on the respiratory, cardiovascular, immune, metabolic, bone, and nervous systems. One major goal is to define relevant IH characteristics leading to safe, protective, and/or therapeutic effects vs. pathogenesis. To understand the impact of IH, it is essential to define critical characteristics of the IH protocol under investigation, including potentially the severity of hypoxia within episodes, the duration of hypoxic episodes, the number of hypoxic episodes per day, the pattern of presentation across time (e.g., within vs. consecutive vs. alternating days), and the cumulative time of exposure. Not surprisingly, severe/chronic IH protocols tend to be pathogenic, whereas any beneficial effects are more likely to arise from modest/acute IH exposures. Features of the IH protocol most highly associated with beneficial vs. pathogenic outcomes include the level of hypoxemia within episodes and the number of episodes per day. Modest hypoxia (9-16% inspired O2) and low cycle numbers (3-15 episodes per day) most often lead to beneficial effects without pathology, whereas severe hypoxia (2-8% inspired O2) and more episodes per day (48-2,400 episodes/day) elicit progressively greater pathology. Accumulating evidence suggests that "low dose" IH (modest hypoxia, few episodes) may be a simple, safe, and effective treatment with considerable therapeutic potential for multiple clinical disorders.

Keywords: dose; intermittent hypoxia; pathogenic; review; therapeutic.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Bone and Bones / metabolism
  • Bone and Bones / physiopathology
  • Cardiovascular System / metabolism
  • Cardiovascular System / physiopathology
  • Humans
  • Hypoxia / complications
  • Hypoxia / immunology
  • Hypoxia / metabolism
  • Hypoxia / physiopathology*
  • Inflammation / metabolism
  • Inflammation / physiopathology
  • Nervous System / metabolism
  • Nervous System / physiopathology
  • Oxygen / metabolism*
  • Respiratory System / metabolism
  • Respiratory System / physiopathology
  • Time Factors


  • Oxygen