Trial Outcomes & Findings for Estimating Apnea Phenotypes From Polysomnography: Oxygen (NCT NCT01751971)

Results Overview

Apnea-hypopnea index (AHI) will be compared between oxygen and sham nights. Hypopneas are based on 30% reduction in airflow (no desaturation or arousal criteria). AHI data are exclusive to non-REM supine sleep. The results presented here are for the AHI at each intervention ("per intervention") regardless of the sequence (preferred clinicaltrials.gov format). Please note, however, that the a priori outcome measure was the reduction in AHI with oxygen as a percent of sham values, i.e. (AHI on sham - AHI on oxygen)/(AHI on sham) % (a comparison with greater statistical power), compared between patient subgroups (see Statistical Analysis section). Subgroups were defined a priori as higher (\>=0.7) versus lower loop gain (\<0.7), but tests were also performed in subgroups defined by "favorable" versus "unfavorable" pathophysiology.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

47 participants

Primary outcome timeframe

1 night

Results posted on

2018-03-20

Participant Flow

Participant milestones

Participant milestones
Measure	Oxygen First Participants participate in inspired oxygen arm (40% oxygen) first, then the air night (21% oxygen) second Inspired oxygen (40%): Supplemental oxygen at approximately 40% e.g. via Pink venturi mask	Air First Participants participate in the air night (sham) first, then the oxygen night second. Sham: Medical air with 21% oxygen e.g. via Pink venturi mask
Overall Study STARTED	22	25
Overall Study COMPLETED	20	24
Overall Study NOT COMPLETED	2	1

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Estimating Apnea Phenotypes From Polysomnography: Oxygen

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Oxygen First n=22 Participants Participants participate in inspired oxygen arm (40% oxygen) first, then the air night (21% oxygen) second Inspired oxygen (40%): Supplemental oxygen at approximately 40% e.g. via Pink venturi mask	Air First n=25 Participants Participants participate in the air night (sham) first, then the oxygen night second. Sham: Medical air with 21% oxygen e.g. via Pink venturi mask	Total n=47 Participants Total of all reporting groups
Age, Continuous	56 years STANDARD_DEVIATION 13 • n=93 Participants	49 years STANDARD_DEVIATION 22 • n=4 Participants	52 years STANDARD_DEVIATION 19 • n=27 Participants
Sex: Female, Male Female	5 Participants n=93 Participants	10 Participants n=4 Participants	15 Participants n=27 Participants
Sex: Female, Male Male	17 Participants n=93 Participants	15 Participants n=4 Participants	32 Participants n=27 Participants

PRIMARY outcome

Timeframe: 1 night

Population: Patients with AHI\>20

Apnea-hypopnea index (AHI) will be compared between oxygen and sham nights. Hypopneas are based on 30% reduction in airflow (no desaturation or arousal criteria). AHI data are exclusive to non-REM supine sleep. The results presented here are for the AHI at each intervention ("per intervention") regardless of the sequence (preferred clinicaltrials.gov format). Please note, however, that the a priori outcome measure was the reduction in AHI with oxygen as a percent of sham values, i.e. (AHI on sham - AHI on oxygen)/(AHI on sham) % (a comparison with greater statistical power), compared between patient subgroups (see Statistical Analysis section). Subgroups were defined a priori as higher (\>=0.7) versus lower loop gain (\<0.7), but tests were also performed in subgroups defined by "favorable" versus "unfavorable" pathophysiology.

Outcome measures

Outcome measures
Measure	Inspired Oxygen n=36 Participants Inspired oxygen (40%) for 1 night via venturi mask.	Sham n=36 Participants Sham: Medical air with 21% oxygen via venturi mask
Apnea-hypopnea Index All patients	40.5 events/hour Standard Error 3.8	57.9 events/hour Standard Error 3.7
Apnea-hypopnea Index Patients with high loop gain (LG1)	48.5 events/hour Standard Error 6.4	74.3 events/hour Standard Error 6.1
Apnea-hypopnea Index Patients with low loop gain (LG1)	35.9 events/hour Standard Error 4.6	48.5 events/hour Standard Error 3.4
Apnea-hypopnea Index Patients with favorable pathophysiology	22.5 events/hour Standard Error 4.3	49.5 events/hour Standard Error 4.8
Apnea-hypopnea Index Patients with unfavorable pathophysiology	51.9 events/hour Standard Error 4.1	63.2 events/hour Standard Error 5.0

SECONDARY outcome

Timeframe: 1 night

Population: Patients with AHI\>20

Frequency of scored EEG arousals per hour of non-REM sleep. Note: Our objective was to describe changes in secondary outcomes within phenotypic subgroups. Overall effects (unselected patients / ignoring phenotypic subgroups) are first presented below, followed by effects in favorable vs. unfavorable subgroups.

Outcome measures

Outcome measures
Measure	Inspired Oxygen n=36 Participants Inspired oxygen (40%) for 1 night via venturi mask.	Sham n=36 Participants Sham: Medical air with 21% oxygen via venturi mask
Frequency of EEG Arousals (Events Per Hour) All patients	35.9 events/hr Standard Error 3.4	50.3 events/hr Standard Error 3.7
Frequency of EEG Arousals (Events Per Hour) Patients with favorable pathophysiology	20.8 events/hr Standard Error 3.0	39.7 events/hr Standard Error 5.1
Frequency of EEG Arousals (Events Per Hour) Patients with unfavorable pathophysiology	45.4 events/hr Standard Error 4.1	57.0 events/hr Standard Error 4.6

SECONDARY outcome

Timeframe: 1 night

Population: Patients with AHI\>20

The change in systolic blood pressure overnight. Two supine oscillometric measurements of blood pressure are made: just prior to lights out (evening), and after lights on (morning).

Outcome measures

Outcome measures
Measure	Inspired Oxygen n=36 Participants Inspired oxygen (40%) for 1 night via venturi mask.	Sham n=36 Participants Sham: Medical air with 21% oxygen via venturi mask
Overnight Change in Systolic Blood Pressure All patients	-0.8 mmHg Standard Error 1.4	3.0 mmHg Standard Error 1.9
Overnight Change in Systolic Blood Pressure Patients with favorable pathophysiology	-2.8 mmHg Standard Error 1.9	3.4 mmHg Standard Error 2.9
Overnight Change in Systolic Blood Pressure Patients with unfavorable pathophysiology	0.5 mmHg Standard Error 1.9	2.8 mmHg Standard Error 2.5

SECONDARY outcome

Timeframe: 1 night

Population: Patients with AHI\>20

The change in diastolic blood pressure overnight. Two supine oscillometric measurements of blood pressure are made: just prior to lights out (evening), and after lights on (morning).

Outcome measures

Outcome measures
Measure	Inspired Oxygen n=36 Participants Inspired oxygen (40%) for 1 night via venturi mask.	Sham n=36 Participants Sham: Medical air with 21% oxygen via venturi mask
Overnight Change in Diastolic Blood Pressure All patients	0.9 mmHg Standard Error 0.9	4.1 mmHg Standard Error 1.5
Overnight Change in Diastolic Blood Pressure Patients with favorable pathophysiology	-0.7 mmHg Standard Error 1.2	6.4 mmHg Standard Error 2.3
Overnight Change in Diastolic Blood Pressure Patients with unfavorable pathophysiology	2.0 mmHg Standard Error 1.2	2.5 mmHg Standard Error 2.0

SECONDARY outcome

Timeframe: 1 night

Population: Patients with AHI\>20. One patient, whose treatment and sham nights were separated by an extended duration (due to scheduling), did not provide data for this outcome measure.

Better(+1)/Same(0)/Worse(-1) on oxygen vs sham, i.e. "a relative comparison between arms". When subjects had completed the entire study, they were asked to compare subjectively their sleep quality on the first versus second study.

Outcome measures

Outcome measures
Measure	Inspired Oxygen n=35 Participants Inspired oxygen (40%) for 1 night via venturi mask.	Sham Sham: Medical air with 21% oxygen via venturi mask
Subjective Sleep Quality (Oxygen vs Sham) All patients	0.34 units on a scale Standard Deviation 0.13	—
Subjective Sleep Quality (Oxygen vs Sham) Patients with favorable pathophysiology	0.69 units on a scale Standard Deviation 0.17	—
Subjective Sleep Quality (Oxygen vs Sham) Patients with unfavorable pathophysiology	0.14 units on a scale Standard Deviation 0.18	—

SECONDARY outcome

Timeframe: 1 night

Population: Patients with AHI\>20

Assessed in the morning after the single night of treatment. Minimum score: 1 (alert), maximum score: 7 (not alert).

Outcome measures

Outcome measures
Measure	Inspired Oxygen n=36 Participants Inspired oxygen (40%) for 1 night via venturi mask.	Sham n=36 Participants Sham: Medical air with 21% oxygen via venturi mask
Subjective Sleepiness/Alertness (Stanford Sleepiness Scale) All patients	2.13 Scores on a scale Standard Error 0.19	2.03 Scores on a scale Standard Error 0.18
Subjective Sleepiness/Alertness (Stanford Sleepiness Scale) Patients with favorable pathophysiology	2.14 Scores on a scale Standard Error 0.32	2.11 Scores on a scale Standard Error 0.26
Subjective Sleepiness/Alertness (Stanford Sleepiness Scale) Patients with unfavorable pathophysiology	2.13 Scores on a scale Standard Error 0.25	1.99 Scores on a scale Standard Error 0.25

Adverse Events

Inspired Oxygen

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Sham

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Scott Sands, PhD

Brigham and Women's Hospital

Phone: 6172780911

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place