Effects of Acute Intermittent Hypoxia on Sensory Function in Healthy Adults

Study Overview
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Brief Summary
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Exposure to acute intermittent hypoxia (AIH) can facilitate of motor output but no studies of sensory effects has been reported.

Detailed Description
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Despite the strong results of motor studies, the affects of AIH on sensory function has not been established. We will use a commercially-available hypoxicator that can be programmed to achieve a targeted level of arterial oxygen saturation. We plan to compare 3 previously published protocols that have generated motor facilitation (and a sham condition) to characterize and effects on sensory function in healthy adults.

Official Title
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Effects of Acute Intermittent Hypoxia on Sensory Function in Healthy Adults

Conditions
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Sensitivity

Intervention / Treatment
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* Device: Intervention 1
* Device: Intervention 2
* Device: Intervention 3
* Device: Intervention 4 (sham)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 to 40 years of age Exclusion Criteria: Diagnosis of cardiovascular disease (Hypertension, arrhythmias, coronary artery disease, congenital and valvar heart diseases) Diagnosis of neuromuscular disease Diagnosis of any neurological disease Presence of concurrent medical illness including infection, fractures Diagnosis of obstructive sleep apnea Diagnosis of obstructive/restrictive lung disease Diagnosis of exercise induced asthma FEV1/FVC<80% and/or FVC<80% of predicted value indicating airway obstruction Subjects on prednisolone therapy or selective serotonin reuptake inhibitor (SSRI) therapy will be excluded from the study as these pharmacological agents are known to amplify the effects of IH[22, 23] Diagnosis of epilepsy or history of seizures and attention deficit disorders Pregnancy Diabetes History of coagulation disorders History of chronic pain Body mass index(BMI)> 35kg/m2 Subjects on prescription medicines such as beta blockers and other drugs that are prescribed in any of the exclusionary disorders listed above.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Within subjects design with randomization of presentation of four different hypoxia/normoxia intervals.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sequence 1<br>Intervention 1: 15 bouts of 2mins:1min hypoxia:hyperoxia Intervention 2: 15 bouts of 1mins:1min hypoxia:hyperoxia Intervention 3: 8 bouts of 2mins:1min hypoxia:hyperoxia 15 bouts of 1min:1min normoxia (sham) | Device: Intervention 1<br>* 15 bouts of 2mins:1min hypoxia:hyperoxia<br>Device: Intervention 2<br>* 15 bouts of 1mins:1min hypoxia:hyperoxia<br>Device: Intervention 3<br>* 8 bouts of 2mins:1min hypoxia:hyperoxia<br>Device: Intervention 4 (sham)<br>* 15 bouts of 1min:1min normoxia<br>|
| Experimental: Sequence 2<br>Intervention 2: 15 bouts of 1mins:1min hypoxia:hyperoxia Intervention 3: 8 bouts of 2mins:1min hypoxia:hyperoxia 15 bouts of 1min:1min normoxia (sham) Intervention 1: 15 bouts of 2mins:1min hypoxia:hyperoxia | Device: Intervention 1<br>* 15 bouts of 2mins:1min hypoxia:hyperoxia<br>Device: Intervention 2<br>* 15 bouts of 1mins:1min hypoxia:hyperoxia<br>Device: Intervention 3<br>* 8 bouts of 2mins:1min hypoxia:hyperoxia<br>Device: Intervention 4 (sham)<br>* 15 bouts of 1min:1min normoxia<br>|
| Experimental: Sequence 3<br>Intervention 3: 8 bouts of 2mins:1min hypoxia:hyperoxia 15 bouts of 1min:1min normoxia (sham) Intervention 1: 15 bouts of 2mins:1min hypoxia:hyperoxia Intervention 2: 15 bouts of 1mins:1min hypoxia:hyperoxia | Device: Intervention 1<br>* 15 bouts of 2mins:1min hypoxia:hyperoxia<br>Device: Intervention 2<br>* 15 bouts of 1mins:1min hypoxia:hyperoxia<br>Device: Intervention 3<br>* 8 bouts of 2mins:1min hypoxia:hyperoxia<br>Device: Intervention 4 (sham)<br>* 15 bouts of 1min:1min normoxia<br>|
| Experimental: Sequence 4<br>15 bouts of 1min:1min normoxia (sham) Intervention 1: 15 bouts of 2mins:1min hypoxia:hyperoxia Intervention 2: 15 bouts of 1mins:1min hypoxia:hyperoxia Intervention 3: 8 bouts of 2mins:1min hypoxia:hyperoxia | Device: Intervention 1<br>* 15 bouts of 2mins:1min hypoxia:hyperoxia<br>Device: Intervention 2<br>* 15 bouts of 1mins:1min hypoxia:hyperoxia<br>Device: Intervention 3<br>* 8 bouts of 2mins:1min hypoxia:hyperoxia<br>Device: Intervention 4 (sham)<br>* 15 bouts of 1min:1min normoxia<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensory Function | Thermal thresholds. Average reported. | Every 10 minutes for 60 minutes post intervention, average reported | 
| Temporal Sensory Summation | Temporal summation represents increases in ratings of pain intensity measured using a numeric pain rating scale (0-no pain to 100-worst pain imaginable) to repeated heat stimuli of the same intensity; that is, summation represents increases in participant ratings of pain despite the maintenance of a standard temperature and is calculated as the difference between pain rating 1 and pain rating 6. Positive difference scores indicate that pain reported increased over the 6 pulses of heat. Here, the average difference across participants and over time is reported. | Every 10 minutes for 60 minutes post intervention, average reported | 
| Sensory Function - Pressure | Pressure threshold is the force at which the sensation of pressure first is considered painful by the participant, average reported | Every 10 minutes for 60 minutes post intervention, average reported | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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thermal threshold, pressure pain threshold, temporal summation