Sex differences in ventricular-vascular interactions associated with aerobic capacity

Area of Science:

• Cardiovascular Physiology
• Exercise Science
• Sports Medicine

Background:

• Maximal oxygen uptake (VO2max) is a key indicator of functional capacity and mortality risk.
• Sex-specific differences in cardiac and vascular responses to training are known, but their impact on VO2max is unclear.

Purpose of the Study:

• To investigate sex-specific interactions between ventricular and vascular factors in relation to VO2max in healthy individuals.
• To understand how cardiac structure, function, and arterial properties contribute to aerobic capacity differently in males and females.

Main Methods:

• Sixty-eight healthy males and females (recreational to elite athletes) underwent VO2max assessment via cycle ergometry.
• Resting arterial compliance and echocardiographic evaluations of left ventricular (LV) structure and function were measured and indexed to body surface area.

Main Results:

• VO2max was similar between sexes, but males had higher indexed LV mass (LVMi).
• In males, LVMi and diastolic strain rate, or end-diastolic volume and diastolic strain rate, predicted VO2max.
• In females, LVMi, arterial compliance, systolic strain rate, and age predicted VO2max, with EDVi also contributing in a separate model.

Conclusions:

• Left ventricular mass and end-diastolic volume are associated with VO2max in both sexes.
• Arterial compliance significantly contributes to VO2max variance in females but not males.
• Ventricular relaxation is key for male aerobic capacity, while ventricular contraction is significant for females.