Livial®:: effects on cardiovascular parameters

Most women living in industrialized societies will die from arterial disease. Women using oral HRT are at less risk than are nonusers; this may be a drug effect or may relate to other differences between users and nonusers. Data on newer therapies such as tibolone (Livial (R)) are scant. Indeed, there is still no incontrovertible evidence that any form of HRT protects against arterial disease. Of recent concern is the failure of a randomised placebo-controlled trial of HRT to show an effect on heart disease. Nonrandomised studies suggest that combined estrogen-progestogen HRT protects against heart disease, contrary to the loss of protection predicted due to the metabolic effects of progestogens. Some progestogens do reduce levels of HDL, but they also reduce those of lipoprotein(a) and triglyceride-rich lipoproteins and also improve fibrinolysis. Likewise, tibolone reduces HDL levels but shares these other potentially beneficial actions. Tibolone improves vascular function and protects fat-fed rabbits from atherosclerosis. Perhaps the clinical consequences of the low HDL levels induced by steroids such as tibolone are outweighed by these other actions? Alternatively, the falls in HDL may not impair HDL function. In the absence of randomised placebo-controlled trials it seems reasonable to suggest that HRT may prevent arterial disease, but any such benefit should be considered generic until proven otherwise. Tibolone shares with estrogen and other postmenopausal therapies the potential to reduce the risk of CHD and stroke, but hard evidence for such protection is not yet available.