Blood pressure response during normocapnic hyperpnoea is blunted in young women compared to men

We hypothesized that young women have a lower arterial blood pressure (BP) response to high inspiratory and expiratory muscle contractions with normocapnic hyperpnoea compared to age-matched men. To test this hypothesis, the cardiovascular response during voluntary normocapnic incremental hyperpnoea was evaluated in young women and compared to that of young men. An incremental respiratory endurance test (IRET) was performed as follows: target minute ventilation was initially set to 30% of the maximal voluntary ventilation (MVV12) and was increased by 10% MVV12 every 3min. The test was terminated when the subject could not maintain the target%MVV. Heart rate and mean arterial BP (MBP) were continuously recorded. The increase in MBP from the baseline (ΔMBP) during the IRET was lower in women than in men (ΔMBP, men: +32.1±4.6mmHg vs. women: +14.9±3.5mmHg at 8min during IRET). This result suggests that young women exhibit a blunted arterial BP response during high-speed inspiratory and expiratory muscle contractions with normocapnic hyperpnoea compared to young men.