Tibolone, oral or transdermal hormone replacement and colour Doppler analysis

Short-term tibolone does not interfere with endothelial function: a double-blinded, randomized, controlled trial

Objective To evaluate the effect of short-term hormone replacement therapy with tibolone 2.5 mg daily on endothelial function of healthy postmenopausal women, using flow-mediated dilation (FMD) of the brachial artery. Methods We performed a randomized, double-blinded, placebo-controlled study. A total of 100 healthy postmenopausal women were randomly allocated to receive tibolone (n = 50) or placebo (n = 50) for 28 days. Measurement of the FMD of the brachial artery was performed before and after the use of tibolone and placebo. Results A total of 31 women completed the study in the tibolone group, and 32 women completed the study in the control group. The results of the FMD measurements obtained from the women in the two groups before treatment were similar (0.018 and 0.091, for tibolone and placebo, p = 0.57). The values of the FMD in women who used tibolone and placebo, before and after the treatment, were similar in both groups. The numbers of women who presented an increase in the values of the FMD in both groups were also similar. Conclusion Our results demonstrate that the administration of 2.5 mg tibolone to healthy postmenopausal women for 28 days does not promote endothelial-dependent vasodilation, measured by FMD of the brachial artery.

Effect of Aerodiol administration on ocular arteries in postmenopausal women

OBJECTIVE

The aim of the present study was to evaluate the alteration of ocular blood hemodynamics after intranasal administration of 17beta-estradiol, through measurement of the ophthalmic artery (OA) and the central retinal artery (CRA) using color duplex sonography.

METHODS

Thirty healthy women who had been naturally postmenopausal for at least 1 year were enrolled in the study. A randomized, placebo-controlled, crossover, double-blinded study was conducted of the acute effect of 17beta-estradiol (Aerodiol; Servier, Chambrayles-Tours, France) on OA and CRA blood flow using color duplex sonography.

RESULTS

The peak systolic and end diastolic velocities of the CRA were increased significantly after 17beta-estradiol administration compared with placebo. A significant decrease was also found in the pulsatility and resistive indices of the CRA. However, there were no statistically significant differences in OA flow velocities or pulsatility and resistive indices.

CONCLUSIONS

Nasal 17beta-estradiol administration in postmenopausal women causes an improvement in the ocular vascular Doppler indices. These results suggest that there could be a positive effect of Aerodiol on middle-sized arteries and arterioles.

Brachial artery responses in menopausal women using tibolone

OBJECTIVE

To determine the effect of tibolone treatment on brachial artery pulsatility index (PI), resistance index (RI), and flux-mediated dilation (FMD) in postmenopausal Mexican women.

METHOD

The FMD, PI, and RI of the right brachial artery were measured in 19 postmenopausal women before and after they received a hyperemic stimulus, first at baseline and then following a 6-month treatment with 2.5 mg of tibolone per day. Statistical analysis was performed using the t test.

RESULTS

The mean+/-SD age was 52.2+/-3.9 years; time since menopause was 24.6+/-16.7 months; and treatment duration was 5.7+/-2.0 months. Compared with prestimulus measurements, a significant poststimulus increase in arterial diameter and a significant decrease in PI were observed at baseline. Compared with prestimulus measurements, a significant poststimulus increase in arterial diameter and a significant decrease in both PI and RI were observed post-treatment.

CONCLUSION

Tibolone treatment had a favorable effect on brachial artery responses to hyperemic stimuli.

Biochemical markers surrogating on vascular effects of sex steroid hormones

The main mechanism of possible cardioprotection by estrogens appears to be a direct effect on the vasculature, resulting in an improvement of endothelial function and inhibition of atherogenesis. Numerous observational and experimental studies have demonstrated a positive correlation between estrogens and various biochemical markers surrogating direct vascular effects. In general, most markers are influenced in a similar way by oral and transdermal hormone therapy, although oral therapy may have a faster and more pronounced effect. The main difference between oral and transdermal administration may be confined to markers that are mainly or exclusively produced in the liver. Clinical studies demonstrate that progestogen addition can have an impact on the beneficial estrogen-induced changes of biochemical markers. Concerning the effects of tibolone, inconsistent data have been found. Overall, tibolone-induced beneficial changes on the various biochemical markers appear to be less marked compared with those of hormone therapy. The few data available on the direct effects of androgens on the vascular wall indicate a less favorable action of androgens on biochemical markers than of estrogens. The practical relevance of marker measurements is currently under discussion. Although evidence strongly supports some of these markers as predictors of acute events, it remains to be established whether modifying circulating levels of these markers will influence outcomes.

The effect of raloxifene and tibolone on the uterine blood flow and endometrial thickness: A transvaginal Doppler study

OBJECTIVES

To evaluate and compare the effect of different than classical hormone therapy medications, such as raloxifene and tibolone, on the uterine arteries and endometrium of postmenopausal women using transvaginal ultrasonography.

METHODS

The prospective study included 62 healthy, postmenopausal women recruited from the Menopausal Clinic of the 2nd Department of Obstetrics and Gynecology of the University of Athens. Subjects were randomly allocated to receive raloxifene HCl in a daily dose of 60 mg orally (Group A-31 women) or tibolone in a daily dose of 2.5 mg orally (Group B-31 women). The study period was 6 months and all subjects were assessed using transvaginal ultrasonography before treatment initiation as well as after 3 and 6 months for evaluation of the endometrial thickness and the pulsatility (PI) and resistance (RI) indices at the level of the uterine arteries.

RESULTS

No significant differences in RI, PI and endometrial thickness were observed in the raloxifene group during the 6-month treatment. In the tibolone group, PI and RI values decreased linearly from baseline to the end of the study, whereas the endometrial thickness was significantly increased during the first 3 months remaining unaltered thereafter. Comparisons between the two study groups revealed significant percent change of values in the pre-treatment to month-3 period and no difference with regard to pre-treatment, month-3 and month-6 absolute values.

CONCLUSION

Raloxifene and tibolone exert dissimilar effects on uterine blood supply parameters and endometrial thickness.