Is the ICP pulse waveform P2/P1 ratio during -6° head-down tilt associated with relative VO₂ peak? A non-invasive intracranial compliance monitoring approach

Author(s)

Zambetta, Rafaella Mendes ; Signini, Etore De Favari ; Catai, Aparecida Maria ; dos Santos, Thaina Cristina Ramos ; Michaliski, Eloisa Soares ; Nazario, Ana Karoline ; Ocamoto, Gabriela Nagai ; Frigieri, Gustavo ; Russo, Thiago Luiz

• Document type: Journal article
• Source: BRAIN AND SPINE; v. 4, p. 6-pg., 2024-08-31.

Abstract

Background: Spaceflights influence intracranial compliance (ICC). P2/P1 ratio, from the intracranial pressure (ICP) waveform, provides information about ICC. Additionally, non-invasive methods for ICC monitoring are needed for spaceflights. Furthermore, astronauts try to maintain good levels of cardiorespiratory fitness before and during spaceflights, not only to sustain exploratory missions, but also to prevent diseases in extreme environments. Objective: to correlate cardiorespiratory fitness levels with the P2/P1 ratio during a microgravity analog [-6 degrees head-down tilt (HDT)]. Method: 34 individuals (11 women), mean age of 31.7 (+/- 6.3) years and BMI 24.2 (+/- 3.2) performed a cardiopulmonary exercise testing (CPET) with an incremental protocol on a cycle ergometer to determine the cardiopulmonary fitness through peak relative oxygen uptake (VO2 peak) of each individual. On the second test, which was conducted in an interval of 15 days of the CPET, participants remained for 30 min at HDT with P2/P1 ratio acquired using a non-invasive strain gauge sensor. The average of the last 5 min was used for analysis. The mean P2/P1 ratio and relative VO2 peak were correlated using the Spearman test. Results: Volunteers presented 1.05 +/- 0.2 of P2/P1 ratio and VO2 peak of 47.5 +/- 7.6 mL/kg/min. The Spearman test indicated a negative and low correlation between the P2/P1 ratio and VO2 peak (rho = -0.388; p = 0.023). Conclusion: The study suggests that the better the cardiorespiratory fitness, the better ICC in a weightlessness simulation. (AU)

• FAPESP's process: 19/14877-8 - Effect of the head-down tilt on intracranial pressure and cardiovascular control in healthy individuals: perspectives for spaceflights
• Grantee: Rafaella Mendes Zambetta
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 18/25082-3 - Study of the metabolic profile in active and sedentary aging: metabolomic approach
• Grantee: Étore de Favari Signini
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 23/00839-2 - Brain oscillations in Alzheimer's Disease: a resting state EEG analysis
• Grantee: Rafaella Mendes Zambetta
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• FAPESP's process: 23/04712-7 - EFFICACY OF MULTIMODAL CIRCUIT TRAINING WITH MODERATE TO HIGH INTENSITY TO INCREASE THE NUMBER OF STEPS AND TO REDUCE SEDENTARY TIME IN PEOPLE WHO HAD STROKE: A RANDOMIZED CLINICAL TRIAL
• Grantee: Thiago Luiz de Russo
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/25569-2 - Effects of negative inclination of the head on intracranial pressure and cardiovascular control in healthy individuals: perspectives for spatial travels
• Grantee: Thiago Luiz de Russo
• Support Opportunities: Regular Research Grants
• FAPESP's process: 23/09582-4 - Study of the integrated profile of cardiovascular autonomic modulation and cardiorespiratory fitness on metabolome and blood count in individuals without diagnosed diseases.
• Grantee: Étore de Favari Signini
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors