Oral contraceptives augment the exercise pressor reflex during isometric handgrip exercise

Area of Science:

• Cardiovascular Physiology
• Exercise Physiology
• Endocrinology

Background:

• The exercise pressor reflex is a critical cardiovascular response during physical activity.
• Gender-related differences in this reflex have been observed, but the influence of hormonal factors like oral contraceptives is not fully understood.

Purpose of the Study:

• To investigate whether oral contraception alters gender-related differences in the exercise pressor reflex during isometric handgrip exercise.
• To compare the reflex responses between men, normally menstruating women, and women using oral contraceptives.

Main Methods:

• Participants (men, normally menstruating women, women on oral contraceptives) performed isometric handgrip exercise.
• Two recovery conditions were tested: arterial occlusion and control (no occlusion).
• Mean arterial pressure (MAP) and systolic blood pressure (sBP) were monitored.

Main Results:

• Men exhibited greater increases in MAP compared to both female groups.
• Women on oral contraceptives (WomenOC) showed higher MAP increases than normally menstruating women (WomenNM).
• Arterial occlusion sustained elevated sBP in men and WomenOC, but not in WomenNM, indicating a blunted metaboreflex in WomenNM.

Conclusions:

• Gender-related differences in the metaboreflex during isometric handgrip exercise exist between men and normally menstruating women.
• These sex-related differences are attenuated in women taking oral contraceptives.
• Oral contraceptives, by suppressing estradiol and/or progestogen, appear to attenuate sex differences in the exercise pressor reflex.