Does tibolone treatment have favorable effects on obesity, blood pressure, and inflammation? A meta-analysis of randomized controlled trials

The effect of tibolone treatment on apolipoproteins and lipoprotein (a) concentrations in postmenopausal women: A meta-analysis of randomized controlled trials

OBJECTIVE

Tibolone is a synthetic steroid with estrogenic, androgenic and progestogenic properties that is used as hormone replacement therapy (HRT) in postmenopausal women. Treatment with tibolone has been demonstrated to lead to changes of the lipid profile, including alterations in lipoprotein (a) and apolipoprotein levels. Hence, we conducted the present meta-analysis of randomized controlled trials (RCTs) to assess the effect of tibolone treatment on apolipoproteins and lipoprotein (a) values in postmenopausal women.

METHODS

Several databases (Cochrane Library, PubMed/Medline, Scopus, and Google Scholar) were searched for English-language manuscripts published up to September 2023 that scrutinized the effects of tibolone administration on apolipoprotein A-I (ApoA-I), apolipoprotein A-II (ApoA-II), apolipoprotein B (ApoB), and lipoprotein (a) in postmenopausal women. The results were reported as the weighted mean difference (WMD) with a 95% confidence interval (CI), generated using a random-effects model.

RESULTS

Finally, 12 publications with 13 RCT arms were included in the current meta-analysis. The overall results from the random-effects model demonstrated a notable reduction in ApoA-I (n = 9 RCT arms, WMD: -34.96 mg/dL, 95 % CI: -42.44, -27.48, P < 0.001) and lipoprotein (a) (n = 12 RCT arms, WMD: -7.49 mg/dl, 95 % CI: -12.17, -2.81, P = 0.002) after tibolone administration in postmenopausal women. However, treatment with tibolone did not impact ApoA- II (n = 4 RCT arms, WMD: 1.32 mg/dL, 95 % CI: -4.39, 7.05, P = 0.64) and ApoB (n = 9 RCT arms, WMD: -2.68 mg/dL, 95 % CI: -20.98, 15.61, P = 0.77) values. In the subgroup analyses, we noticed a notable decrease in lipoprotein (a) levels when tibolone was prescribed to females aged < 60 years (WMD: -10.78 mg/dl) and when it was prescribed for ≤ 6 months (WMD: -15.69 mg/dl).

CONCLUSION

The present meta-analysis of RCTs highlighted that treatment with tibolone reduces lipoprotein (a) and apolipoprotein A-I levels in postmenopausal women. As the decrease in serum lipids' concentrations is associated with a decrease in the risk of cardiovascular disease (CVD), treatment with tibolone could be a suitable therapy for postmenopausal women with elevated CVD risk.

Pharmacological interactions and menopausal hormone therapy: a review

IMPORTANCE AND OBJECTIVE

Menopausal hormone therapy (HT) is widely used, and there are several statements of international scientific societies to guide prescribers; however, a summary of existing literature about possible drug interactions with HT does not exist, although many midlife women take medications for other conditions. Therefore, our objective was to create a document that presents and synthesizes the most relevant interactions. The impact of the interaction itself and the number of candidates for HT who are likely to use other treatments are considered based on the best available evidence.

METHODS

A systematic review was performed to determine the best evidence of interaction effects on relevant outcomes of interest for decision making. A working framework was developed to formulate explicit and reasoned recommendations according to four predefined categories for coadministration: (1) can be used without expected risks, (2) acceptable use (no evidence of negative interaction), (3) alternative treatment should be considered, and (4) nonuse without express justification. The project protocol was registered in the Open Science Framework platform (doi: 10.17605/OSF.IO/J6WBC) and in PROSPERO (registration number CRD42020166658).

RESULTS

Studies targeting our objective are scarce, but 23 pharmacological groups were assigned to one of the predefined categories of recommendation for concomitant use of HT. Vaginal HT was assigned to category 1 for 21 of the analyzed pharmacological groups. For oral and transdermal HT (estrogen-only or combined) and tibolone, there were 12 pharmacological groups assigned to category 1, 12 to category 2, 5 to category 3, and 4 to category 4. Results are shown in crossed-tables that are useful for counseling and prescription.

DISCUSSION AND CONCLUSIONS

Available evidence of HT interactions with other drugs is scarce and mainly indirect. It comes from biological plausibility, knowledge of extensive concomitant use without reported incidents, and/or extrapolation from hormonal contraception, but there are pharmacological groups in all categories showing that information is useful. These eligibility criteria summarize it and can help in the decision process of HT coadministration with other drugs. Decisions should be taken based on these recommendations but also individualized risk/benefit evaluation, according to underlying pathology, patient's clinical requirements, and the existence or nonexistence of alternatives.

Roles of estrogens, estrogen-like compounds, and endocrine disruptors in adipocytes

Women are subject to constitutional changes after menopause, which increases conditions and diseases prone to cardiovascular risks such as obesity and diabetes mellitus. Both estrogens and androgens influence the individual's metabolic mechanism, which controls the fat distribution and the hypothalamic organization of the regulatory centers of hunger and satiety. While androgens tend to accumulate fat in the splanchnic and the visceral region with an increase in cardiovascular risk, estrogens generate more subcutaneous and extremity distribution of adipose tissue. The absence of estrogen during menopause seems to be the main factor that gives rise to the greater predisposition of women to suffer cardiovascular alterations. However, the mechanisms by which estrogens regulate the energy condition of people are not recognized. Estrogens have several mechanisms of action, which mainly include the modification of specific receptors that belong to the steroid receptor superfamily. The alpha estrogen receptors (ERα) and the beta receptors (ERβ) have a fundamental role in the metabolic control of the individual, with a very characteristic corporal distribution that exerts an influence on the metabolism of lipids and glucose. Despite the significant amount of knowledge in this field, many of the regulatory mechanisms exerted by estrogens and ER continue to be clarified. This review will discuss the role of estrogens and their receptors on the central regulation of caloric expenditure and the influence they exert on the differentiation and function of adipocytes. Furthermore, chemical substances with a hormonal activity that cause endocrine disruption with affectation on estrogen receptors will be considered. Finally, the different medical therapies for the vasomotor manifestations of menopause and their role in reducing obesity, diabetes, and cardiovascular risk will be analyzed.