Neurokinin 3 receptor antagonism for menopausal hot flashes

Risks and benefits of hormone therapy after menopause for cognitive decline and dementia: A conceptual review

OBJECTIVE

The effects on the brain of hormone therapy after the onset of menopause remain uncertain. The effects may be beneficial, neutral, or harmful. We provide a conceptual review of the evidence.

METHODS

We 1) provide a brief history of the evidence, 2) discuss some of the interpretations of the evidence, 3) discuss the importance of age at menopause, type of menopause, and presence of vasomotor symptoms, and 4) provide some clinical recommendations.

RESULTS

The evidence and the beliefs about hormone therapy and dementia have changed over the last 30 years or more. Five recent observation studies suggested that hormone therapy is associated with an increased risk of dementia, and the association appears not to change with the timing of initiation of therapy. These harmful associations may be explained by a causal effect of hormone therapy on the brain or by several confounding mechanisms. We suggest that the use of hormone therapy should be customized for different subgroups of women. It may be important to subgroup women based on age at onset of menopause, type of menopause, and presence or absence of vasomotor symptoms. In addition, the effects may vary by type, dose, route, and duration of administration of estrogens and by the concurrent use of progestogens.

DISCUSSION

The relation of hormone therapy with the risk of dementia is complex. Hormone therapy may have beneficial, neutral, or harmful effects on the brain. Hormone therapy should be guided by the clinical characteristics of the women being treated.

Fezolinetant for the treatment of vasomotor symptoms associated with menopause: a meta-analysis

This systematic review and meta-analysis investigated the efficacy and safety of fezolinetant for the treatment of moderate-to-severe vasomotor symptoms (VMS) associated with menopause. PubMed, Cochrane Library, Embase and Web of Science were searched for randomized controlled trials (RCTs) published from inception to June 2023, comparing fezolinetant to placebo in postmenopausal women suffering from moderate-to-severe VMS. The mean difference and risk ratio were calculated for continuous and binary outcomes, respectively. R software was used for the statistical analysis, and RoB-2 (Cochrane) to assess the risk of bias. We performed subgroup analysis based on different dosing regimens. Five RCTs comprising 3302 patients were included. Compared with placebo, at 12-week follow-up, fezolinetant significantly reduced the daily frequency of moderate-to-severe VMS (weighted mean difference [WMD] - 2.36; 95% confidence interval [CI] - 2.92, -1.81) and daily severity of moderate-to-severe VMS (WMD -0.22; 95% CI -0.31, -0.13). Also, fezolinetant significantly improved the quality of life (WMD -0.42; 95% CI -0.58, -0.26) and sleep disturbance (WMD -1.10; 95% CI -1.96, -0.24). There were no significant differences between groups in adverse events. These findings support the efficacy and safety of fezolinetant for the treatment of VMS related to menopause.

KNDy Neurons of the Hypothalamus and Their Role in GnRH Pulse Generation: an Update

There is considerable evidence that synchronized activity within a reciprocally connected population of cells in the arcuate nucleus (ARC) coexpressing kisspeptin, neurokinin B (NKB), and dynorphin (KNDy cells) is crucial for the generation of gonadotrophin-releasing hormone (GnRH) pulses in mammals. The initial "KNDy hypothesis" proposed that pulsatile GnRH secretion is elicited by episodic kisspeptin release from KNDy cells following synchronized activation and termination of the population by NKB and dynorphin, respectively. Since then, the role of KNDy cells as a critical component of the pulse generator has been further supported by studies at the single-cell level, demonstrating that the population is both necessary and sufficient for pulsatility. In addition, there have been considerable modifications and expansion of the original hypothesis, including work demonstrating the critical role of glutamate in synchronization of the KNDy cell network, functional interactions with other ARC subpopulations, and the existence of species differences in the role of dynorphin in pulse generation. Here we review these recent changes and discuss how the translation of these findings has led to the development of new therapies for disorders related to pulse generation. We also outline critical gaps in knowledge that are currently limiting the application of KNDy research in the clinic, particularly regarding the role of dynorphin in pulse generation in primates.