Sensitivity
Conditions
Keywords
thermal threshold, pressure pain threshold, temporal summation
Brief summary
Exposure to acute intermittent hypoxia (AIH) can facilitate of motor output but no studies of sensory effects has been reported.
Detailed description
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.
Interventions
DEVICEIntervention 1
15 bouts of 2mins:1min hypoxia:hyperoxia
DEVICEIntervention 2
15 bouts of 1mins:1min hypoxia:hyperoxia
DEVICEIntervention 3
8 bouts of 2mins:1min hypoxia:hyperoxia
DEVICEIntervention 4 (sham)
15 bouts of 1min:1min normoxia
Sponsors
University of Florida
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
Participants can't see the device and therefore the settings. The assessment of sensory function is done by a separate investigator who did not participate in the set up of the hypoxicator
Intervention model description
Within subjects design with randomization of presentation of four different hypoxia/normoxia intervals.
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sensory Function | Every 10 minutes for 60 minutes post intervention, average reported | Thermal thresholds. Average reported. |
| Temporal Sensory Summation | Every 10 minutes for 60 minutes post intervention, average reported | 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. |
| Sensory Function - Pressure | Every 10 minutes for 60 minutes post intervention, average reported | Pressure threshold is the force at which the sensation of pressure first is considered painful by the participant, average reported |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Sequence 1 15 bouts of 2mins:1min hypoxia:hyperoxia 15 bouts of 1mins:1min hypoxia:hyperoxia 8 bouts of 2mins:1min hypoxia:hyperoxia 15 bouts of 1min:1min normoxia | 5 |
| Sequence 2 15 bouts of 1mins:1min hypoxia:hyperoxia 8 bouts of 2mins:1min hypoxia:hyperoxia 15 bouts of 1min:1min normoxia 15 bouts of 2mins:1min hypoxia:hyperoxia | 5 |
| Sequence 3 8 bouts of 2mins:1min hypoxia:hyperoxia 15 bouts of 1min:1min normoxia 15 bouts of 2mins:1min hypoxia:hyperoxia 15 bouts of 1mins:1min hypoxia:hyperoxia | 5 |
| Sequence 4 15 bouts of 1min:1min normoxia 15 bouts of 2mins:1min hypoxia:hyperoxia 15 bouts of 1mins:1min hypoxia:hyperoxia 8 bouts of 2mins:1min hypoxia:hyperoxia | 5 |
| Total | 20 |
Baseline characteristics
| Characteristic | Sequence 1 | Total | Sequence 4 | Sequence 3 | Sequence 2 |
|---|---|---|---|---|---|
| Age, Continuous | 26.4 years STANDARD_DEVIATION 6.3 | 22.0 years STANDARD_DEVIATION 5.1 | 20.8 years STANDARD_DEVIATION 2.1 | 20.8 years STANDARD_DEVIATION 2 | 19.2 years STANDARD_DEVIATION 1.1 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 3 Participants | 9 Participants | 3 Participants | 1 Participants | 2 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 2 Participants | 1 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 2 Participants | 9 Participants | 1 Participants | 3 Participants | 3 Participants |
| Region of Enrollment United States | 5 participants | 20 participants | 5 participants | 5 participants | 5 participants |
| Sex: Female, Male Female | 4 Participants | 10 Participants | 0 Participants | 3 Participants | 3 Participants |
| Sex: Female, Male Male | 1 Participants | 10 Participants | 5 Participants | 2 Participants | 2 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 22 |
| other Total, other adverse events | 0 / 22 |
| serious Total, serious adverse events | 0 / 22 |
Outcome results
Primary
Sensory Function
Thermal thresholds. Average reported.
Time frame: Every 10 minutes for 60 minutes post intervention, average reported
Population: A 2-way analysis of co-variance with repeated measures (time\*intervention) was conducted with gender as the covariate.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Intervention 1 | Sensory Function | 46.7 Degrees celsius | Standard Deviation 1.5 |
| Intervention 2 | Sensory Function | 46.4 Degrees celsius | Standard Deviation 1.9 |
| Intervention 3 | Sensory Function | 46.1 Degrees celsius | Standard Deviation 1.9 |
| Intervention 4 (Sham) | Sensory Function | 45.9 Degrees celsius | Standard Deviation 2.1 |
p-value: 0.592ANCOVA
Primary
Sensory Function - Pressure
Pressure threshold is the force at which the sensation of pressure first is considered painful by the participant, average reported
Time frame: Every 10 minutes for 60 minutes post intervention, average reported
Population: A 2-way analysis of co-variance with repeated measures (time\*intervention) was conducted with gender as the covariate.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Intervention 1 | Sensory Function - Pressure | 4.4 kilograms force | Standard Deviation 3.4 |
| Intervention 2 | Sensory Function - Pressure | 4.6 kilograms force | Standard Deviation 2.5 |
| Intervention 3 | Sensory Function - Pressure | 4.3 kilograms force | Standard Deviation 2.8 |
| Intervention 4 (Sham) | Sensory Function - Pressure | 4.3 kilograms force | Standard Deviation 3.1 |
p-value: 0.553ANCOVA
Primary
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.
Time frame: Every 10 minutes for 60 minutes post intervention, average reported
Population: 2-way repeated measures ANOVA with gender as the covariate
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Intervention 1 | Temporal Sensory Summation | 17.4 score on a scale | Standard Deviation 13.3 |
| Intervention 2 | Temporal Sensory Summation | 11.7 score on a scale | Standard Deviation 10.2 |
| Intervention 3 | Temporal Sensory Summation | 10.9 score on a scale | Standard Deviation 11.2 |
| Intervention 4 (Sham) | Temporal Sensory Summation | 11.9 score on a scale | Standard Deviation 15.6 |
p-value: 0.721ANCOVA