Current ecology, not ancestral dispersal patterns, influences menopause symptom severity

Abstract

All human females who reach midlife experience menopause, however, it is currently unclear why women experience this period of infertility, and why it is accompanied by many unpleasant symptoms. Using primary data from four ethnic groups in China, we test an existing theory that age of menopause and its symptoms are the result of intragenomic conflict between maternally and paternally inherited genes, with the outcome of such conflict predicted to be contingent on the ancestral postmarital residence pattern of the female (Úbeda, Ohtsuki, & Gardner, Ecology Letters, 17, 2014, 165). The model predicts that being ancestrally patrilocal results in less intragenomic conflict, causing a shorter, less symptomatic perimenopause that terminates in a later menopause. Our findings show no support for this hypothesis and suggest current, rather than ancestral, residence patterns better predict aspects of the menopausal transition. Furthermore, current patrilocality when compared to duolocality is associated with more severe menopause symptoms, which may be due to sexual, rather than intragenomic, conflict. Open Research Badges This article has earned an Open Data Badge for making publicly available the digitally‐shareable data necessary to reproduce the reported results. The data is available at https://doi.org/10.5061/dryad.27s8k0p.

The relationship between social support, stressful events, and menopause symptoms

“…In recent years, different social and ecological factors have been found to associate with VMS, including ethnicity, living arrangements, and socioeconomic position (SEP) [ 3 , 12 , 15 ]. Importantly, it has been argued that stress may mediate the relationship between such factors and the women’s reported menopause symptoms [ 12 , 16 ].…”

“…In recent years, different social and ecological factors have been found to associate with VMS, including ethnicity, living arrangements, and socioeconomic position (SEP) [ 3 , 12 , 15 ]. Importantly, it has been argued that stress may mediate the relationship between such factors and the women’s reported menopause symptoms [ 12 , 16 ]. Experience of stressors and increased perceived stress have been linked to higher levels of cortisol and fibrinogen, with the former being associated with the suppression of the immune, reproductive, and digestive systems, and the latter with increased inflammation [ 17 ].…”

“…However, while all women experience these hormonal changes during the menopausal transition, not all report VMS [5]: while population estimates vary [6], it is thought that over 70% of all women experience VMS at some point during the menopausal transition [3,7], meaning the minority of women do not experience VMS. Further, even amongst the women who do report VMS, the symptomatology is not uniform within and between populations, with women reporting them to varying degrees of severity and frequency [3,[8][9][10][11][12][13]. Given the negative impact of VMS reported by women [14], it is important to understand what co-varies with VMS prevalence and severity, as it may better equip women to deal with the menopausal transition.…”

The evolutionary ecology of age at natural menopause: implications for public health

“…Recent studies on menopause timing view age at menopause as a facultative adaptation – i.e. menopausal age varies in response to ecology in a way that maximises fitness ( Chan, Gomes, & Singh, 2020 ; Galbarczyk & Jasienska, 2013 ; Skjaervo & Roskaft, 2013 ; Yang, Arnot, & Mace, 2019 ). Those studies are generally silent with regards to physiological understandings of ovarian ageing, however.…”

“…Recent research into the timing of menopause has taken an adaptive stance. In this view, menopause is a facultative trait where menopause timing responds to ecological factors such as daughter’s reproductive success, dispersal patterns and living in the matrilineal/patrilineal household ( Cant & Johnstone, 2008 ; Skjaervo & Roskaft, 2013 ; Yang et al, 2019 ). Studies have found little support for modification of menopausal age based on either mediating factor, nor have they given suggestions for physiological mechanisms to explain how age at menopause could be affected by factors such as dispersal and daughter’s reproductive success.…”