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This Article Full Text Full Text (PDF) All Versions of this Article: 293/6/H3568    most recent 00725.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Lindenberger, M. Articles by Länne, T. PubMed PubMed Citation Articles by Lindenberger, M. Articles by Länne, T.

Decreased capillary filtration but maintained venous compliance in the lower limb of aging women

¹Division of Physiology, Department of Medicine and Care, Linköping University, Linköping, Sweden; and ²Division of Cardiology, Department of Medicine, Ryhov County Hospital, Jönköping, Sweden

Submitted 21 June 2007 ; accepted in final form 28 September 2007

There are sex-related differences in venous compliance and capillary filtration in the lower limbs, which to some extent can explain the susceptibility to orthostatic intolerance in young women. With age, venous compliance and capacitance are reduced in men. This study was designed to evaluate age-related changes in venous compliance and capillary filtration in the lower limbs of healthy women. Included in this study were 22 young and 12 elderly women (23.1 ± 0.4 and 66.4 ± 1.4 yr). Lower body negative pressure (LBNP) of 11, 22, and 44 mmHg created defined transmural pressure gradients in the lower limbs. A plethysmographic technique was used on the calf to assess venous capacitance and net capillary filtration. Venous compliance was calculated with the aid of a quadratic regression equation. No age-related differences in venous compliance and capacitance were found. Net capillary filtration and capillary filtration coefficient (CFC) were lower in elderly women at a LBNP of 11 and 22 mmHg (0.0032 vs. 0.0044 and 0.0030 vs. 0.0041 ml·100 ml^–1·min^–1·mmHg^–1, P < 0.001). At higher transmural pressure (LBNP, 44 mmHg), CFC increased by 1/3 (0.010 ml·100 ml^–1·min^–1·mmHg^–1) in the elderly (P < 0.001) but remained unchanged in the young women. In conclusion, no age-related decrease in venous compliance and capacitance was seen in women. However, a decreased CFC was found with age, implying reduced capillary function. Increasing transmural pressure increased CFC in the elderly women, indicating an increased capillary susceptibility to transmural pressure load in dependent regions. These findings differ from earlier studies on age-related effects in men, indicating sex-specific vascular aging both in the venous section and microcirculation.

capillary filtration coefficient; lower body negative pressure; age