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

Meendering, Jessica R.; Torgrimson, Britta N.; Houghton, Belinda L.; Halliwill, John R.; Minson, Christopher T.

doi:10.1152/ajpheart.00691.2004

Cited by 34 publications

(46 citation statements)

References 39 publications

(60 reference statements)

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“…2B and METHODS). In contrast to others, we did not increase the intravascular pressure by means of a thigh cuff (6,17,20,34,39,47), but applied negative pressure around the leg caused by LBNP.…”

Section: Discussioncontrasting

confidence: 83%

“…2B, Table 2) (34,39). The C cap in the legs is linked to the capacitance response, and the lower C cap in women explains their lower capacitance response in the present study (Fig.…”

Section: Discussionmentioning

confidence: 48%

“…This seems to be refuted however, by recent findings that demonstrate a lower venous compliance in women (34,39). In these studies, compliance has been evaluated on the basis of the calf volume-venous pressure relationship after several minutes of venous stasis, although capillary fluid filtration significantly increases calf tissue volume (26).…”

mentioning

confidence: 99%

“…Because of the conflicting results with lower venous compliance in the lower extremities in women despite an increased orthostatic intolerance (34,39), we wanted to reevaluate sexrelated differences in venous compliance and capacitance. Thus the aim of the present study was to define the capacitance response and capillary filtration in the calves of young women and men in response to defined transmural pressure gradients, as well as to calculate venous compliance and assess the impact of capillary filtration.…”

mentioning

confidence: 99%

“…No subjects were taking any regular medication, except oral contraceptive pills. Each woman was scheduled in the middle 2 wk of her menstrual cycle not excluding oral contraceptive use (six women), since the effect of menstrual cycle and oral contraceptives on venous compliance and LBNP response seems to be minor (8,34,35). Each subject gave informed consent to the experiments approved by the Ethics Committee of Linköping University, Linköping, Sweden.…”

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confidence: 99%

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Sex-related effects on venous compliance and capillary filtration in the lower limb

Lindenberger

Länne²

2007

American Journal of Physiology-Regulatory, Integrative and Comp

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Recent studies in humans have suggested sex differences in venous compliance of the lower limb, with lower compliance in women. Capillary fluid filtration could, however, be a confounder in the evaluation of venous compliance. The venous capacitance and capillary filtration response in the calves of 12 women (23.2 Ϯ 0.5 years) and 16 men (22.9 Ϯ 0.5 years) were studied during 8 min lower body negative pressure (LBNP) of 11, 22, and 44 mmHg. Calf venous compliance is dependent on pressure and was determined using the first derivative of a quadratic regression equation that described the capacitance-pressure relationship [compliance ϭ ␤ 1 ϩ (2 ⅐ ␤2 ⅐ transmural pressure)]. We found a lower venous compliance in women at low transmural pressures, and the venous capacitance in men was increased (P Ͻ 0.05). However, the difference in compliance between sexes was reduced and not seen at higher transmural pressures. Net capillary fluid filtration and capillary filtration coefficient (CFC) were greater in women than in men during LBNP (P Ͻ 0.05). Furthermore, calf volume increase (capacitance response ϩ total capillary filtration) during LBNP was equivalent in both sexes. When total capillary filtration was not subtracted from the calf capacitance response in the calculation of venous compliance, the sex differences disappeared, emphasizing that venous compliance measurement should be corrected for the contribution of CFC. lower body negative pressure; capillary filtration coefficient; venous capacitance THE VENOUS SECTION OF THE cardiovascular system can be looked upon as a voluminous blood reservoir (70% of total blood volume), designed to preserve a proper inflow of blood into the heart during various cardiovascular adjustments. Thus central venous pressure and filling of the heart may be maintained at a fairly stable level, despite variations in venous blood volume (49). During upright posture, however, the pooling of blood in the veins of the lower part of the body decreases central blood volume and venous return (4, 5, 16). The venous compartment in the legs, rather than the pelvic or abdominal region, seems to have a hemodynamic impact during lower body negative pressure (LBNP) (16), and in studies on men, a greater calf venous compliance has been linked to an increased venous capacitance response with a concomitant reduction in central blood volume (44,56). This, in turn, elicits an increased sympathetic response with higher peripheral resistance and increased heart rate (4, 5, 10, 16, 44, 58). Thus venous compliance of the lower limb may have an impact on cardiovascular responses to orthostatic stress and orthostatic tolerance, although there might be differences between sexes confounding such a link (4).Women are more susceptible to orthostatic stress than men (4,10,13,40,51,58), and in accordance with some findings in the arterial tree, it may be hypothesized that women have greater venous compliance in the lower limbs predisposing to orthostatic intolerance (52). This seems to be refuted however, by recent fi...

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Section: Discussioncontrasting

confidence: 83%

“…2B, Table 2) (34,39). The C cap in the legs is linked to the capacitance response, and the lower C cap in women explains their lower capacitance response in the present study (Fig.…”

Section: Discussionmentioning

confidence: 48%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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