Effects of menstrual cycle and oral contraceptive use on calf venous compliance

Abstract

Numerous studies have shown that the female sex hormones estrogen and progesterone have multiple effects on the vasculature. Thus our goal was to investigate the effects of estrogen and progesterone on calf venous compliance by looking for cyclic changes during the early follicular, ovulatory, and midluteal phases of the menstrual cycle and during high and low hormone phases of oral contraceptive use. Additionally, we wanted to compare the venous compliance of normally menstruating women, oral contraceptive users, and men. We studied eight normally menstruating women (23 ± 1 yr of age) during the early follicular, ovulatory, and midluteal phases of the menstrual cycle. Nine triphasic oral contraceptive users (21 ± 1 yr of age) were studied during weeks of high and low hormone concentrations. Eight men (23 ± 1 yr of age) were studied twice within 2–4 wk. With the use of venous occlusion plethysmography with mercury in-Silastic strain gauges, lower limb venous compliance was measured by inflating a venous collection cuff that was placed on the thigh to 60 mmHg for 8 min and then reducing the pressure to 0 mmHg at a rate of 1 mmHg/s. Venous compliance was calculated as the derivative of the pressure-volume curves. There were no differences between early follicular, ovulatory, and midluteal phases of the menstrual cycle or between high and low hormone phases of oral contraceptive use ( P > 0.05). Male venous compliance was significantly greater than in normally menstruating women ( P < 0.001) and oral contraceptive users ( P < 0.002). These data support a sex difference but also suggest that venous compliance does not change with menstrual cycle phase or during the course of oral contraceptive use.