Intravascular Volumes in Hypoxia During Antarctic Confinement
Anahtar kelimeler
Öz
Açıklama
INTRODUCTION: Short-term space flight induces an alteration of circulating blood volumes, termed "space flight anemia" and characterized by a decrease in total red blood cell volume (RCV) and plasma volume (PV). This haematological alteration is likely to persist during a long-term space mission and impact the astronauts' health, however this question remains unexplored. During a long-term space mission, the use of hypobaric hypoxia is considered for technical reasons, however the safety of hypoxia must first be verified because this environmental condition causes substantial physiological changes, in particular changes in blood volumes that may interact with the haematological effects of microgravity.
OBJECTIVE: using the Antarctic confinement model as a high-fidelity terrestrial analogue for long-duration space missions, the investigators hypothesize that 1) sea level confinement reduces blood volume by simultaneously decreasing RCV and PV, and 2) chronic hypoxia offsets the decrease in RCV and exacerbates the decrease in PV induced by confinement.
METHODS: blood volumes will be measured via the carbon-monoxide rebreathing method, repeatedly in two groups of participants, overwintering either at Dumont d'Urville (sea level) or Concordia (altitude 3200 m). The blood viscosity will also be measured, as well as the markers of erythropoiesis and iron metabolism.
PERSPECTIVE: Documenting if some degree of hypoxia during long-duration confinement may be beneficial or unfavorable in terms of blood volume regulation is potentially relevant information for the astronauts' health and safety during long-duration space missions.
Tarih
| Son Doğrulandı: | 08/31/2019 |
| İlk Gönderilen: | 09/22/2019 |
| Tahmini Kayıt Gönderildi: | 09/24/2019 |
| İlk Gönderilen: | 09/26/2019 |
| Son Güncelleme Gönderildi: | 10/21/2019 |
| Son Güncelleme Gönderildi: | 10/22/2019 |
| Fiili Çalışma Başlangıç Tarihi: | 09/26/2019 |
| Tahmini Birincil Tamamlanma Tarihi: | 12/30/2021 |
| Tahmini Çalışma Tamamlanma Tarihi: | 12/30/2022 |
Durum veya hastalık
Müdahale / tedavi
Other: carbon-monoxide rebreathing
Other: venous blood sampling
Other: physical activity monitoring
Other: apnea-hypopnea index and nocturnal oxygenation
Other: 24-hour blood pressure
Evre
Kol Grupları
| Kol | Müdahale / tedavi |
|---|---|
| Experimental: hypoxia & confinement Participants exposed to high-altitude hypoxia and confinement during a one-year stay at Concordia station, Antarctica (3200 m) | |
| Active Comparator: confinement Participants exposed to confinement during a one-year stay at Dumont d'Urville station, Antarctica (sea level) |
Uygunluk kriterleri
| Çalışmaya Uygun Yaşlar | 18 Years İçin 18 Years |
| Çalışmaya Uygun Cinsiyetler | All |
| Sağlıklı Gönüllüleri Kabul Ediyor | Evet |
| Kriterler | Inclusion Criteria: - Affiliated to a social security scheme - Ability to communicate and read in English or in French - Signed written informed consent form after visit with a MD Exclusion Criteria: - Pregnant, lactating or parturient women - Cardiovascular, pulmonary or neuromuscular disease - Vulnerable persons |
Sonuç
Birincil Sonuç Ölçütleri
1. total hemoglobin mass [15 months]
2. total red blood cell volume [15 months]
3. total blood volume [15 months]
4. plasma volume [15 months]
İkincil Sonuç Ölçütleri
1. blood viscosity [15 months]
2. serum erythropoietin [15 months]
3. serum hepcidin [15 months]
4. serum erythroferrone [15 months]
5. serum transferrin saturation [15 months]
6. serum ferritin [15 months]
7. serum soluble transferrin receptor [15 months]
8. Physical activity [15 months]
9. Apnea-hypopnea index [15 months]
10. Nocturnal oxygenation [15 months]
11. 24-hour blood pressure [15 months]
