MULTI-SYSTEM PHYSIOLOGIC RESPONSE TO VARYING LEVELS OF PARTIAL GRAVITY (GRAVIDOSE)

Spaceflight induces detrimental changes in most organ systems with both acute changes and chronic adaptations. For example, acute fluid shifts associated with weightlessness (also called - improperly - microgravity) cause initial rapid cardiovascular alterations, whereas the chronic changes are more reflective of cardiovascular deconditioning and cerebrovascular/ocular adaptations (Pavy-Le Traon et al., 2007).

Long-duration stays in weightlessness have resulted in ocular structural and functional adaptations in some astronauts, which has been termed the Spaceflight Associated Neuro-ocular Syndrome (SANS ; see review in Lee et al., 2018). The leading hypothesis is that ocular changes are the consequence of chronic exposure to the weightlessness-induced headward (cephalad) fluid shift experienced by all astronauts. Countermeasures targeted to reverse this fluid shift, including lower body negative pressure and veno-occlusive thigh cuffs, have been proposed and tested in ground-based studies using a head-down tilt model of the cephalad fluid shift. However, the amount of fluid shift reversal required to prevent the development of SANS has not been investigated or determined. Similarly, artificial gravity through centrifugation has been proposed as a SANS countermeasure, given its ability to reverse headward fluid shifts and its efficacy as a countermeasure to long-duration bed rest-induced cardiovascular adaptations (long-duration bed rest is widely employed to simulate the effects of microgravity on various physiological systems). However, the minimum level of artificial gravity required also has not been investigated.

The primary objective of this study is to characterize cardiovascular, cerebrovascular, and ocular changes across a range of gravity levels to identify a threshold of gravitational load that can serve as a countermeasure to SANS during future spaceflight missions.

Study Overview

• Status: Completed
• Conditions: Healthy Volunteers
• Intervention / Treatment: Other: parbolic flight

• Study Type: Interventional
• Enrollment (Actual): 18
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Caen, France
    • CHU Caen

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy volunteers (men or women)
• Aged from 18 to 65
• Affiliated to a Social Security system and, for non-French resident, holding a European Health Insurance Card (EHIC)
• Who accepted to take part in the study
• Who have given their written stated consent
• Who have passed a medical examination similar to a standard aviation medical examination for private pilot aptitude (JAR FCL3 Class 2 medical examination). There will be no additional test performed for subject selection.

Exclusion Criteria:

• Persons who took part in a previous biomedical research protocol, of which exclusion period is not terminated
• Pregnant women (urine pregnancy test for women of childbearing potential)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraocular Pressure	will be assessed continuously using the Triggerfish	baseline

Collaborators and Investigators

• Sponsor: University Hospital, Caen

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2019
• Primary Completion (Actual): June 12, 2020
• Study Completion (Actual): December 15, 2020

Study Registration Dates

• First Submitted: May 23, 2019
• First Submitted That Met QC Criteria: May 23, 2019
• First Posted (Actual): May 28, 2019

Study Record Updates

• Last Update Posted (Estimate): May 5, 2023
• Last Update Submitted That Met QC Criteria: May 4, 2023
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Other Study ID Numbers: 18-072

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