Autonomic Activity During Nap Under Hypoxia

Not Applicable

Completed

• Conditions: Hypoxia; Sleep; Healthy
• Interventions: Other: Hypoxia 1; Other: Normoxia; Other: Hypoxia 2

• Registration Number: NCT04146857
• Lead Sponsor: Charite University, Berlin, Germany

Brief Summary

Sleeping under hypoxic conditions can impair cognition and autonomic nervous activity. A short daytime nap can modify these changes. Here we propose a randomized, cross-over study to evaluate the heart rate variability during a 90 min nap in a normobaric hypoxic chamber. In addition, we will investigate sleep architecture, vigilance, attention and memory.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2019-10-25
• Study Start: 2019-10-30
• Study First Submitted QC: 2019-10-30
• Study First Posted: 2019-10-31
• Primary Completion: 2020-12-30
• Study Completion: 2020-12-30
• Status Verified: 2022-07
• Last Update Submitted: 2022-07-07
• Last Update Posted: 2022-07-11

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 16

Inclusion Criteria

• Men and women
• Age 25-45 years
• BMI 20 - 28 kg/m^2

Exclusion Criteria

• Severe, manifest illnesses in need of treatment
• Postoperative phases
• Acute and chronic infections
• Sleep disorders such as sleep apnea, insomnia or somnolence
• Altitude exposure (> 2500 m asl) within 6 months before enrollment
• Regular migraines
• Smoking
• Athletes
• Significant weight change within 1 month before enrollment
• Inability to understand significance and scope of the study
• Drug or alcohol abuse

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Hypoxia 1	Hypoxia 1	15.0% oxygen
Normoxia	Normoxia	20.9% oxygen
Hypoxia 2	Hypoxia 2	12.8% oxygen

Primary Outcome Measures

Name	Time	Method
Heart rate variability	During 90 minutes nap under normoxic (20.9%) vs. 12.8% hypoxic condition	Mean RR interval measured by polysomnography (ms)

Secondary Outcome Measures

Name	Time	Method
Wake After Sleep Onset (WASO)	During 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Measured by continuous polysomnography (min)
Digit Span Task	After 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Longest memorized digit series (n, normal range 5-9, higher is better)
Low Frequency / High Frequency Band	During 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Mean LF/HF ratio measured by continuous ECG
RR intervals longer than 50 ms	During 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Percentage pNN50 measured by continuous ECG (%)
Psychomotor Vigilance Task Subscale 2	After 90 min nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Mean reaction time (normal range 100-500 ms, higher is worse)
Color Stroope Task Subscale 4	After 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Congruent accuracy (above 95% is normal, higher is better)
Sleep Onset Latency (SOL)	During 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Measured by continuous polysomnography (min)
Heart rate variability	During 90 minutes nap under normoxic (20.9%) vs. 15.0% hypoxic condition	Mean RR interval measured by polysomnography (ms)
Sleep Efficiency (SE)	During 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Measured by continuous polysomnography (min)
Standard Deviation 1 / Standard Deviation 2	During 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Mean SD1/SD2 ratio measured by continuous ECG
Skin Temperature	During 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Mean temperature measured by continuous double sensor monitoring (°C)
Color Stroope Task Subscale 1	After 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Number of incongruency errors (normal range 0-5, higher is worse)
Core Body Temperature	During 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Mean temperature measured by continuous double sensor monitoring (°C)
Psychomotor Vigilance Task Subscale 1	After 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Number of lapses (normal range 0-6, higher is worse)
Color Stroope Task Subscale 2	After 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Congruent response time (normal range 400-500 ms, higher is worse)
Color Stroope Task Subscale 3	After 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Incongruent response time (normal range 600-800 ms, higher is worse)
Color Stroope Task Subscale 5	After 90 minutes nap under normoxic (20.9%) vs. two hypoxic conditions (12.8 and 15%)	Incongruent accuracy (above 85% is normal, higher is better)

Trial Locations

Locations (1)

Experimental & Clinical Research Center; 🇩🇪 Berlin, Germany