Modeling sex-dependent cardiovascular responses to lower body negative pressure

Bergauer, Andrej (avtor), Urevc, Janez (avtor), Halilovič, Miroslav (avtor), Batzel, Jerry J. (avtor), Pivec, Vid (avtor), Goswami, Nandu (avtor)

Lower-body negative pressure (LBNP) induces controlled central hypovolemia, yet the regional mechanisms of cardiovascular compensation remain difficult to resolve experimentally. This study presents a computational framework for estimating regional parameter changes consistent with observed hemodynamic responses to progressive LBNP using a refined lumped-parameter model calibrated to experimental data. Hemodynamic responses to graded LBNP (0 to −40 mmHg) and recovery were obtained from a previously published experimental study in 35 healthy adults (17 females, 18 males), including heart rate, cardiac output, arterial pressure, total peripheral resistance, and ultrasound-derived internal jugular and portal venous flow. The model was structurally refined by separating head and arm circulations, enabling explicit modeling of cerebral venous outflow and jugular vein dynamics, and calibrated using a sensitivity- and correlation-guided identification strategy. Baseline calibration revealed distinct vascular architectures, with males exhibiting higher arterial compliance and dominant lower-body resistance, and females showing greater splanchnic and renal tone. During progressive LBNP, the identified splanchnic resistance increased monotonically in both sexes, whereas lower-body resistance rose markedly in males but remained near baseline in females, indicating sex-dependent compensation strategies. The calibrated model quantifies regional vascular resistance changes and venous blood volume redistribution during hypovolemia, providing a model-based interpretation of possible regulatory mechanisms into sex-specific cardiovascular regulation that cannot be directly measured in vivo.

• Jezik: Angleški jezik
• Ključne besede: cardiovascular system, hemodynamics, computational modeling, baroregulation, sex differences, lower body negative pressure
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2026
• Št. strani: Str. H240-H259
• Številčenje: Vol. 331, iss. 1
• PID: 20.500.12556/RUL-184107
• UDK: 612.1:519.6
• ISSN pri članku: 0363-6135
• DOI: 10.1152/ajpheart.00258.2026
• COBISS.SI-ID: 280868611
• Datum objave v RUL: 29.06.2026

Gradivo je del revije

• Naslov: American journal of physiology : heart and circulatory physiology
• Skrajšan naslov: Am J Physiol Heart Circ Physiol
• Založnik: American Physiological Society.
• ISSN: 0363-6135
• COBISS.SI-ID: 24932096

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: srčno žilni sistem, hemodinamika, matematično modeliranje, baroregulacija, razlika med spoloma, negativni tlak

Projekti

• Financer: Drugi - Drug financer ali več financerjev
• Program financ.: European Space Agency
• Številka projekta: 4000137614/22/NL/SC
• Naslov: Prediction model of countermeasures efficiency on cardiovascular system and fluid shifting in simulated microgravity conditions