Heritability of Venous

Chronic venous disease (CVD) is one of the most common cardiovascular disorders in Northern and Western Europe; however, the causative factors predisposing individuals to the disease are still under investigation. Age, sex, obesity, and family history were found to be major risk factors for CVD. Altered venous biomechanics may also contribute to the pathogenesis of venous disease. Twin studies have been extensively used to characterize the interaction of genetic and environmental factors on cardiovascular phenotypes. A CVD twin study reported 84% phenotypic concordance between monozygotic (MZ) twins, compared with only 39% between dizygotic (DZ) twins. Fiebig et al evaluated the relative genetic and environmental impact upon CVD risk by estimating the heritability of the disease in 4033 nuclear families, comprising 16 434 individuals from all over Germany. The heritability of CVD proved to be high, thereby suggesting a notable genetic component in the pathogenesis of the disease. Altered venous biomechanics may be a predisposing phenotypic factor for the development of this disease. However, the level of genetic determination of venous biomechanics is less known. Brinsuk et al, using the impedance plethysmography technique in a twin study of 46 twin pairs, found that both venous compliance and venous capacity are substantially influenced by genetic factors. No previous attempts, however, to reveal the heritability of venous elasticity have been done, when using more accurate ultrasonographic techniques and making the venous elasticity measurements in different postures and under controlled pressure changes. The present study was done to differentiate between inherited and environmental factors in venous biomechanical phenotype by comparison of MZ and DZ twins. The aim of our present work was to evaluate the heritability of in situ static and dynamic venous biomechanics.