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NCT Number: NCT07423988

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

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..

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Key information

Conditions

Sleep Disorder (Disorder) Altitude Sickness Mental Disorders Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Respiration Disorders Respiratory Tract Diseases Signs and Symptoms Sleep Wake Disorders

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Unité du sommeil, Hôpital Pierre Paul Riquet, 1 place du Docteur Baylac

Toulouse, Oui, 31059, France

Location status: Recruiting

Location contact

Emeline MULLER

CONTACT

[email protected]

0561778707

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Sleep recording

Other

Polysomnography and questionnaires.

Primary outcomes

  1. Comparison of sleep efficiency (total sleep time / total sleep period) under high altitude conditions (at 2877 m) versus without increased altitude (at home)

    Time frame: 1 week after the inclusion

    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.

Secondary outcomes

  1. 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"

    Time frame: 1 week after the inclusion

    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.

  2. Measurement of sleep parameters in low altitude conditions for the group "without on-call nights at high altitude"

    Time frame: 1 week after the inclusion

    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.

  3. Evaluation of the relationship between sleep quantification criteria and sleep disorder criteria

    Time frame: 1 week after the inclusion

    Comparison of questionnaire responses and polysomnographic recording

  4. Correlation between cardiac parameters and sleep efficiency.

    Time frame: 1 week after the inclusion

    Correlation between heart rate variability and sleep efficiency using polysomnography recording

  5. Comparison of sleep parameters, in conditions without increased altitude, between the 2 groups of participants

    Time frame: 1 week after the inclusion

    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

Study contacts

Contact information is provided by the study sponsor or research team.

Rachel DEBS, MD

CONTACT

[email protected]

05 61 77 94 88 ext. + 33

Sponsors and collaborators

Lead sponsor

University Hospital, Toulouse

Other

Registry information

Official study title

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

Acronym: ALTISOM

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Feb 20, 2026
Registry last updated
Apr 8, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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