The long-term effects of tibolone on aortic stiffness and endothelial function

• Published in: Climacteric : the journal of the International Menopause Society 2005-09, Vol.8 (3), p.221-229
• Main Authors: Bruce, D., Rymer, J., Robinson, J., Millasseau, S., Chowienczyk, P.
• Format: Article
• Language: English
• Subjects: Aorta - physiology; Aortic stiffness; Blood Flow Velocity - physiology; Brachial Artery - diagnostic imaging; Brachial Artery - physiology; Cardiovascular disease; Carotid Arteries - physiology; Cholesterol, HDL - blood; Controlled Clinical Trials as Topic; Cross-Sectional Studies; Endothelial function; Endothelium, Vascular - physiology; Estrogen Receptor Modulators - therapeutic use; Female; Femoral Artery - physiology; Health risk assessment; Hemorheology; Hormone replacement therapy; Humans; London - epidemiology; Long-term; Menopause; Norpregnenes - therapeutic use; Pilot Projects; Postmenopause; Preventive medicine; Prospective Studies; Pulsatile Flow - physiology; Smoking - epidemiology; Tibolone; Ultrasonography; Vasodilation - physiology; Women
• ISSN: 1369-7137; 1473-0804
• DOI: 10.1080/13697130500103441

Objective To investigate the effect of 10 years of treatment with tibolone on aortic stiffness and endothelial function. Design Cross-sectional study of women currently participating in an open-label, non-randomized study of the long-term efficacy of tibolone. A total of 113 recently postmenopausal women were recruited in 1988. Fifty-eight agreed to take tibolone 2.5 mg daily and 55 were followed during the study as matched controls (who chose not to take any form of hormone replacement therapy (HRT) for the duration of the study). The groups were matched for age, weight and time since last menstrual period. Setting A Central London Teaching Hospital. Subjects After 10 years, 60 women remained in the study, 32 in the tibolone group and 28 in the control group. All of these women were invited to participate in this pilot study and attend the Menopause Research Unit. Fourteen women from each group agreed to attend. The main outcome measures were aortic stiffness, measured by pulse wave velocity, and endothelial function, as assessed by flow-mediated dilatation of the brachial artery. Results Pulse wave velocity was significantly lower in the tibolone group (10.4 ± 1.2) than in the control group (11.6 ± 1.2), p = 0.042. The flow-mediated dilatations were similar in both groups. Conclusion In this study, long-term use of tibolone over 10 years has a beneficial effect on aortic stiffness. The differences seen in brachial artery vasoreactivity failed to reach statistical significance. Whether this is a true indication of the effects of long-term tibolone on brachial artery vasoreactivity will only be determined by performing a larger, placebo-controlled, randomized study.