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Published on: May 8, 2021
Spontaneous variability analysis for characterizing cardiovascular responses to water ingestion
Masaki Nozawa1, Kazuo Yana, Kaoru Kaeriyama
1Department of Electronic Informatics, Hosei University, Tokyo 184-8584, Japan.
Drinking water significantly increases blood pressure and total peripheral resistance, helping to prevent fainting (syncope). This study confirms water ingestion
Area of Science:
- Cardiovascular Physiology
- Autonomic Nervous System Function
- Hemodynamics
Background:
- Water ingestion is known to affect blood pressure, particularly in individuals with autonomic disorders.
- Autonomic dysfunction can lead to syncope (fainting) due to inadequate blood pressure regulation.
Purpose of the Study:
- To precisely characterize the cardiovascular effects of isotonic water ingestion in healthy young adults.
- To investigate the role of total peripheral resistance in mediating the anti-syncope effects of water.
Main Methods:
- Head-up tilt experiments at 80 degrees were performed on 14 healthy subjects (aged 16-24).
- Measurements included systolic/diastolic blood pressure (sBP/dBP), total peripheral resistance index (TRPI), and ECG RR intervals (RRIs) before and after 340 ml water ingestion.
- Advanced fluctuation analysis, including heart rate (HR) spectral analysis (DCSI method) and closed-loop system identification, was employed.
Main Results:
- Statistically significant increases were observed in sBP (2.8%), dBP (3.6%), and TRPI (5.3%) post-ingestion.
- RRIs showed a non-significant trend towards increase (2.3%).
- Water ingestion demonstrated an acute effect against syncope, primarily attributed to increased TRPI.
Conclusions:
- Ingestion of 340 ml of water acutely increases blood pressure and total peripheral resistance in healthy individuals.
- The observed hemodynamic changes suggest a mechanism for preventing syncope, likely mediated by enhanced vascular tone.
- Advanced analytical techniques provide precise characterization of cardiovascular responses to water ingestion.
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