Evaluation of Changes in Sleep Efficiency Among PIC DU MIDI Staff Between Nights Spent at Home and Nights Spent in the Workplace Under High Altitude Conditions (ALTISOM)

Evaluation of Changes in Sleep Efficiency Among PIC DU MIDI Employees Between Nights Spent at Home (Without Increased Altitude) and Nights Spent in a Professional Environment Under High Altitude Conditions

Sleep organization and cardiorespiratory parameters are disrupted in extreme conditions such as high altitude. The pathophysiology of medical problems related to acute high-altitude exposure is partially understood, but sleep quality indicators are very rarely measured under these conditions. This lack of information is even more pronounced among employees subjected to cyclical exposure to high-altitude hypoxic stress, as is the case for the employees at the Pic du Midi. These 32 employees regularly report to their occupational physician difficulties in managing their sleep disorders, struggling to distinguish symptoms from objective changes in their sleep cycles. Among them, 13 are on call at the summit of the Pic du Midi (2,877 m), while 19 work there during the day and return home to a lower altitude at night to sleep. The investigators also wish to measure structural changes in sleep and its cardiorespiratory parameters using polysomnography in these 13 employees, comparing nights spent at home at normal altitude with those spent at the summit of the Pic du Midi. These changes will also be compared to those of a group of 19 employees who do not sleep at high altitude..

Study Overview

• Status: Recruiting
• Conditions: Sleep Disorder (Disorder)
• Intervention / Treatment: Other: Sleep recording

• Study Type: Interventional
• Enrollment (Estimated): 32
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Rachel DEBS, MD; Phone Number: + 33 05 61 77 94 88; Email: debs.r@chu-toulouse.fr

Study Locations

• France
  • Oui
    • Toulouse, Oui, France, 31059
      • Recruiting
      • Unité du sommeil, Hôpital Pierre Paul Riquet, 1 place du Docteur Baylac
      • Contact: Emeline MULLER; Phone Number: 0561778707; Email: muller.e@chu-toulouse.Fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Group "with on-call night at high altitude at the Pic du Midi":

• Employed at the Pic du Midi for at least one month
• Working nights at high altitude (at the Pic du Midi, altitude of 2877m) as part of their professional activity
• Person affiliated with or covered by a social security scheme
• Free, informed, and written consent signed by the participant and the investigator

Night group "without on-call night at high altitude":

• Employed at the Pic du Midi for at least one month
• Not working nights at high altitude (at the Pic du Midi, altitude of 2877m) as part of their professional activity
• Person affiliated with or covered by a social security scheme social
• Free, informed and written consent signed by the participant and the investigator

Exclusion Criteria:

• For all participants:
• History of cardiovascular disease
• Use of cardiovascular/psychotropic medication
• Participant under legal guardianship or other protective regime (guardianship, curatorship)
• Pregnant or breastfeeding woman
• French language proficiency insufficient to complete the questionnaires

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: group with overnight on-call duty at high altitude at the Pic du Midi; employees of the Pic du Midi who spend the night at high altitude	Other: Sleep recording; Polysomnography and questionnaires.
Active Comparator: group without night duty at high altitude; employees of the Pic du Midi who spend the night at home in the plain	Other: Sleep recording; Polysomnography and questionnaires.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison of sleep efficiency (total sleep time / total sleep period) under high altitude conditions (at 2877 m) versus without increased altitude (at home)	Sleep efficiency will be compared, according to the ratio = total sleep time (TST)/ total sleep period (PTS) calculated from a polysomnographic recording, between the night spent at high altitude (2877m, at PIC du MIDI) and the second night spent at home (not increased altitude) among PIC du MIDI employees performing on-call nights at high altitude.	1 week after the inclusion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison of sleep parameters in high altitude conditions versus without increased altitude for the group "with on-call night at high altitude at Pic du Midi"	Sleep parameters (determined according to the criteria of the American Academy of Sleep Medicine (AASM)) measured from a polysomnographic recording will be compared in high altitude conditions versus without increased altitude.	1 week after the inclusion
Measurement of sleep parameters in low altitude conditions for the group "without on-call nights at high altitude"	Sleep parameters (determined according to the criteria of the American Academy of Sleep Medicine (AASM)) will be measured from a polysomnographic recording under conditions without altitude gain.	1 week after the inclusion
Evaluation of the relationship between sleep quantification criteria and sleep disorder criteria	Comparison of questionnaire responses and polysomnographic recording	1 week after the inclusion
Correlation between cardiac parameters and sleep efficiency.	Correlation between heart rate variability and sleep efficiency using polysomnography recording	1 week after the inclusion
Comparison of sleep parameters, in conditions without increased altitude, between the 2 groups of participants	Comparison of sleep parameters (determined according to the criteria of the American Academy of Sleep Medicine (AASM)) from the polysomnography recording between the two groups in conditions without increased altitude	1 week after the inclusion

Collaborators and Investigators

• Sponsor: University Hospital, Toulouse

Study record dates

Study Major Dates

• Study Start (Actual): March 23, 2026
• Primary Completion (Estimated): February 1, 2027
• Study Completion (Estimated): February 28, 2027

Study Registration Dates

• First Submitted: January 8, 2026
• First Submitted That Met QC Criteria: February 13, 2026
• First Posted (Actual): February 20, 2026

Study Record Updates

• Last Update Posted (Actual): April 8, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: sleep; sleep disorder; high altitude; cardiorespiratory parameters
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Respiratory Tract Diseases; Respiration Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Sleep Wake Disorders; Altitude Sickness
• Other Study ID Numbers: RC31/24/0575; ID-RCB (Other Identifier: 2026-A00289-42)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No