Effect of acute intermittent hypoxia on motor function in individuals with chronic spinal cord injury following ibuprofen pretreatment: A pilot study

J Spinal Cord Med. 2017 May;40(3):295-303. doi: 10.1080/10790268.2016.1142137. Epub 2016 Feb 9.


Introduction: Acute intermittent hypoxia (AIH) enhances lower extremity motor function in humans with chronic incomplete spinal cord injury (SCI). AIH-induced spinal plasticity is inhibited by systemic inflammation in animal models. Since SCI is frequently associated with systemic inflammation in humans, we tested the hypothesis that pretreatment with the anti-inflammatory agent ibuprofen enhances the effects of AIH.

Methods: A randomized, double-blinded, placebo-controlled crossover design was used. Nine adults (mean age 51.1 ± 13.1 years) with chronic motor-incomplete SCI (7.7 ± 6.3 years post-injury) received a single dose of ibuprofen (800 mg) or placebo, 90 minutes prior to AIH. For AIH, 9% O2 for 90 seconds was interspersed with 21% O2 for 60 seconds. Maximal voluntary ankle plantar flexion isometric torque was assessed prior to, and at 0, 30, and 60 minutes post-AIH. Surface electromyography (EMG) of plantar flexor muscles was also recorded.

Results: Torque increased significantly after AIH at 30 (P = 0.007; by ∼20%) and 60 (P < 0.001; by ∼30%) minutes post-AIH versus baseline. Ibuprofen did not augment the effects of AIH. EMG activity did not increase significantly after AIH; however, there was a significant association between increases in torque and EMG in both gastrocnemius (R2 = 0.17, P < 0.005) and soleus (R2 = 0.17, P < 0.005) muscles.

Conclusions: AIH systematically increased lower extremity torque in individuals with chronic incomplete SCI, but there was no significant effect of ibuprofen pretreatment. Our study re-confirms the ability of AIH to enhance leg strength in persons with chronic incomplete SCI.

Keywords: Humans; Hypoxia; Ibuprofen; Muscle strength dynamometer; Neuronal plasticity; Rehabilitation; Spinal cord injury.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Analgesics, Non-Narcotic / administration & dosage
  • Analgesics, Non-Narcotic / therapeutic use*
  • Female
  • Humans
  • Ibuprofen / administration & dosage
  • Ibuprofen / therapeutic use*
  • Isometric Contraction*
  • Male
  • Middle Aged
  • Oxygen / administration & dosage*
  • Oxygen / therapeutic use
  • Oxygen Inhalation Therapy / adverse effects
  • Oxygen Inhalation Therapy / methods*
  • Pilot Projects
  • Spinal Cord Injuries / drug therapy
  • Spinal Cord Injuries / therapy*


  • Analgesics, Non-Narcotic
  • Oxygen
  • Ibuprofen