Venous endothelial function in postmenopausal women who are receiving long-term estrogen and progestagen therapy

Objective: To test venous endothelial function during long-term hormone replacement therapy (HRT) and after treatment withdrawal. Design: Measurement of dorsal hand-vein diameter by venous occlusion plethysmography during infusion of norepinephrine, bradykinin, NG-monomethyl l-arginine, and sodium nitroprusside. Setting: Plethysmography and menopause units, University Hospital Marques de Valdecilla, Santander, Spain. Patient(s): Twenty postmenopausal women, of whom 10 were assigned to receive no hormone replacement therapy (HRT) for 6 months after plethysmography (group A) and 10 were assigned to receive HRT for 6 months (group B). After 6 months, HRT was administered to group A and withdrawn from group B for another 6 months. Intervention(s): Plethysmography at baseline and at 6 and 12 months. Main Outcome Measure(s): Dorsal hand-vein diameter measured by venous occlusion plethysmography during infusion of norepinephrine, bradykinin, NG-monomethyl l-arginine, or sodium nitroprusside. Result(s): At 6 months, the maximum dilation obtained with bradykinin was 48.8 ± 7.58% in group A and 76.7 ± 12.9% in group B. At 12 months, maximum bradykinin dilation increased to 74.3 ± 14.2% in group A and decreased to 54.0 ± 15.9% in group B. Conclusion(s): Long-term HRT with estrogen plus progestin improves endothelium-dependent vasodilation, but this effect is lost in a relatively short time. Endothelial function in dorsal hand veins is an easy-to-use plethysmography model that can be used in serial studies.