Estrogen Influences on Neuromuscular Function in Postmenopausal Women

Abstract

Exposure to ovarian sex steroids during different life phases has long-term effects on women's health and wellbeing. Menopause is characterized by rapid decline in ovarian sex steroids already during mid-life, between the ages of 46 and 52. Due to the menopause-related hormonal changes, women in most western countries live more than one-third of their lives in postmenopausal status. The role of ovarian steroids on neuromuscular function in middle-aged and older women has been investigated since the 1980s with increasing volume of research during the last decades. This review considers how different components of the neuromuscular system may be influenced by estrogens and so affects neuromuscular function in postmenopausal women. The main focus is on muscle strength and power, which are closely associated with mobility and functional capacity among older populations. In the end of the review, we summarize recent findings on the underlying biological mechanisms in skeletal muscle that could explain the association between hormone replacement therapy and neuromuscular function among postmenopausal women.

Changes in body composition and weight during the menopause transition

“…Thus, an MT-related shift in fluid regulation could contribute to our observed reduction in lean mass. There have been some investigations of the relation between menopause and muscle, but these have compared pre-vs. postmenopausal women or made inferences based on age rather than MT stage (35,36). Nonetheless, these studies suggest plausible means by which the MT may diminish muscle mass, such as upregulation of skeletal muscle catabolism or lessened muscle response to anabolic stimuli (e.g., resistance training) (35).…”

“…may preserve the muscle transcriptome and benefit muscle strength (36). Progesterone can increase protein synthesis in women; therefore, persistently low progesterone levels could contribute to a decline in lean mass (37).…”

Estrogenic regulation of skeletal muscle proteome: a study of premenopausal women and postmenopausal MZ cotwins discordant for hormonal therapy

“…Menopausal transition is characterized by irregular menstrual cycle leading eventually to amenorrhea, concomitantly with a shift in hormonal balance from higher E 2 and lower follicle‐stimulating hormone (FSH) to constantly low E 2 and high FSH levels (Harlow et al ., ; Baber et al ., ). Although sex differences in skeletal muscle metabolism and the role of ovarian hormones and benefits of postmenopausal hormone replacement therapy (HRT) in combating aging‐related decrements of muscle properties have gained a significant interest in last decades (e.g., Greising et al ., ; Velders & Diel, ; Sipilä et al ., ; Gheller et al ., ), current knowledge base is overwhelmingly contributed by male studies with fewer input coming from studies concentrating on female‐specific aspects of aging.…”

Terapia hormonal de la menopausia, ¿por qué prescribirla?

“…El estudio WHI evaluó el efecto de la THM sobre las caídas, un fuerte predictor de fractura, señalan-do que las mujeres que toman al menos el 80% de su terapia sufren menos caídas que las mujeres controles (35) . En ello puede estar influyendo el rol que los estrógenos tienen en la función neuromuscular, el cual se refleja en la existencia de más de 200 genes que son modulados por el estradiol y que tienen que ver con el trofismo muscular; a ello hay que agregar que la THM disminuye microRNAs (miRNA-182, miRNA-223), lo cual activa vías anabólicas (IGF-1/PI3K/AKT) que impactan positivamente al sistema muscular (36) . El déficit de estrógenos puede explicar en algún grado la sarcopenia que presentan las mujeres de avanzada edad.…”