The influence of menopausal status on sleep quality in different populations – a narrative review

Introduction

Menopause is a significant physiological change that affects women worldwide, marking the end of menstrual cycles and fertility. This transition is not only a hallmark of aging but also a period associated with various health challenges and symptoms, significantly impacting women’s lives [1]. Among these, sleep disturbances are notably prevalent, affecting a considerable proportion of menopausal women across different populations [2]. These disturbances are linked to a spectrum of consequences, from diminished well- being to heightened chances of developing chronic conditions such as cardiovascular diseases, diabetes, and obesity. The complexity of menopausal symptoms, including hot flashes, night sweats, and hormonal fluctuations, directly contributes to the degradation of sleep quality, making this issue a key point of focus for medical professionals and researchers alike.
Menopausal transition involves four stages: premenopausal, perimenopausal, menopausal, and postmenopausal. Each of these stages is characterized by individual ailments and hormonal changes [3, 4]. The premenopausal period is still referred to as the reproductive period. It begins between the ages of 30 and lasts until 40 in women of European descent. During this period, a woman usually does not experience the typical ailments/disorders of menopausal transition. The only changes that occur are hormonal. Women enter perimenopause at different ages, however, for most it is after the age of 40. This may be dictated by their ethnicity, lifestyle, iatrogenic interventions or diet. Climacteric occurs as a result of hormonal fluctuations in the female body after premenopausal period. During this phase women usually experience irregular periods, headaches, muscle aches and many vasomotor symptoms (VMS) like hot flashes, sleep disturbance, mood changes, vaginal dryness [5, 6]. During menopause, which is defined as the day on which a woman has not had a monthly bleeding for exactly twelve months and on average after the age of 50, VMS intensify [1]. Premature menopause can be caused inter alia, by genetic predisposition, metabolic disorders, autoimmune diseases or hysterectomy with oophorectomy [7]. Postmenopause is a term that blurs with menopause. Because the day after menopause, a woman already enters the postmenopausal phase. As mentioned before, during the menopausal transition, the risk of comorbidities such as sleep and metabolic disorders, cardiovascular diseases or osteoporosis insignificantly increases due to hormonal imbalance [8–10]. Diseases/disorders resulting from menopausal transition that interfere with the quality of sleep include obstructive sleep apnea (OSA), insomnia and snoring [11, 12]. Obstructive sleep apnea can be a consequence of obesity, the risk of which also increases with menopausal transition. It consists in the complete or partial collapse of the upper airway during sleep. Insomnia is one of the most common sleep diseases, characterized by difficulty falling asleep, waking up at night, chronic fatigue, daytime sleepiness and mood changes.
The intersection/connection of menopausal status with ethnic and cultural backgrounds presents a unique set of challenges and variations in how symptoms are experienced and managed. Research indicates that the prevalence and severity of menopausal symptoms, including sleep disturbances, can vary significantly among different populations, suggesting the influence of genetic, environmental, lifestyle, and cultural factors.
This review aims to fill a gap in understanding how the menopausal transition affects sleep quality across different ethnic and cultural populations. By analyzing studies conducted in various demographic groups, it aspires to provide insightful information on cultural, genetic, and environmental factors that influence sleep disorders. This fresh approach highlights the importance of considering ethnic and cultural differences in medical research and clinical practice.

Purpose of the study

The main purpose of this review is to analyze how menopausal status influences sleep quality among women of diverse ethnic backgrounds, examining the existing literature to highlight similarities and differences in experiences and outcomes. This narrative review also aims to highlight the significance of adopting culturally aware strategies for addressing menopausal symptoms and enhancing sleep quality by examining specific ethnic groups. Additionally, it stresses the importance of gaining a thorough understanding of menopausal transitions across different cultures and societies tailor interventions to meet the specific needs of women during this critical period of their lives. By examining a wide range of available studies, this review contributes to the ongoing conversation/discussion about menopause, sleep quality, and how cultural differences impact health outcomes during the menopausal transition.

Material and methods

This review gathered and analyzed evidence from research on menopausal status and its effects on sleep quality among various populations. A comprehensive search of databases including PubMed and Cochrane was conducted for articles published between 2007 and 2023. Selection criteria were based on the relevance to menopausal status, sleep disorders, and ethnic diversity. Keywords included “menopause”, “premenopausal stage”, “postmenopausal stage”, “perimenopausal stage”, “premature menopause”, “menopausal transition”, “sleep quality”, “insomnia”, “poor sleep quality”, “sleep difficulty”, “depression”, “ethnicity”, “cultural factors”, “obstructive sleep apnea”, “vasomotor symptoms”. The review was meticulously structured to encompass a wide range of studies, ensuring a broad perspective on the subject matter. Only articles that examined sleep disturbances and quality in the context of different stages of menopause and included data on diverse populations were included in the review. Studies that did not clearly categorize menopausal stages and/or did not account for ethnic diversity were excluded. The selection process involved screening titles and abstracts, followed by a thorough review of the full texts to ensure that the studies were statistically relevant and met quality standards. The review was divided into chapters, including the influence of the menopausal status on sleep quality, intensity of VMS during menopausal transition and their impact on sleep quality, most common sleep disorders in menopausal transition, prevalence and severity of sleep disorders according to ethnicity and stages of menopause, possible ways to treat menopause-related disorders.

Influence of the menopausal status on sleep quality

Changes in hormonal balance, including a decrease in the level of inhibin B [13] and higher cortical amyloid-β deposition [14] during menopausal transition, contribute to a decrease in the quality of sleep in women.
Tom et al. performed a comprehensive study analyzing moderate and severe sleep difficulties. The study compared a group of 938 participants with moderate sleep difficulties with a control group of 4072 participants with no sleep difficulties, and a group of 888 participants with severe sleep difficulties with 3125 participants without sleep difficulties. The risk of moderate sleep difficulties was higher in perimenopausal women (OR 1.35), in women who were transitioning to postmenopause (OR 1.48), and after hysterectomy (OR 1.56 in the fully-adjusted model), when compared to the control group. The risk of severe sleep difficulties was higher for women transitioning from premenopause to perimenopause (OR 1.60), remaining perimenopausal more than doubled the odds ratio (OR 2.23), and moving to postmenopause nearly tripled the odds (OR 2.84) when compared to the control group [7].
Blümel et al. analyzed 6,079 women aged 40–59 years old across 11 Latin American countries. The researchers found a notable increase in sleep disturbances correlated with advancing menopausal status. Insomnia prevalence escalated from 39.7% in the younger age group (40–44 years old) to 45.2% among those aged 55–59 old. Similarly, the rate of women who reported poor sleep quality increased 40.3–49.3%/increased by …. between these age groups. Additionally, the study showed that sleep disturbances were strongly associated with VMS, depressive mood, and anxiety, increasing in women undergoing menopausal transition. These associations highlight the compounded impact of menopausal symptoms on sleep quality [15].
The majority of studies show that the prevalence of symptoms like insomnia and poor sleep quality increase with age and stages of menopausal status [16–18]. Blümel et al. used the menopause rating scale (MRS) and presented that the rate of women indicating sleep disturbances increased from 49.6% among women aged 40–44 years old to 75.8% in those aged 55–59 years old [3]. Berecki-Gisolf et al. analyzed an array of different symptoms prevalent among midlife women, having aimed to distinguish those directly linked to the menopausal transition from those attributable to aging. The source of data was the Australian Longitudinal Study on Women’s Health, which encompassed 8,649 participants, whose status of natural menopause was ascertainable, providing a detailed exploration of the effects associated with the menopausal phase. However, due to longitudinal examination, 79% of these women reached natural menopause before the study’s conclusion. The odds risk increased with the advancement of menopausal status, with OR 1.40 between 1–4 years before menopause, OR 1.57 at the time of menopause, and OR 1.62 between 1–4 years after menopause [1].
Another study from Saudi Arabia showed that there was a notable association between poor sleep quality and higher MRS scores, specifically linking somatic and urogenital symptoms with worsened sleep quality (p < 0.001). The average Pittsburgh sleep quality index (PSQI) score among the women was 6.10, distinguishing “good sleepers” (65.4% who had scored ≤ 5 points) from “poor sleepers” (34.6% who had scored > 5 points). The prevalence of poor sleep quality increased with age and was significantly associated with menopausal status. Women in the earlier years of postmenopause exhibited poorer sleep quality. The authors suggested that women were more likely to have disturbances of sleep due to estrogen declining during menopause. Somatic symptoms, urogenital symptoms, and the overall average MRS score were directly correlated with inferior/worse sleep quality (p < 0.001) [9]. In another study about sleep quality and its association with menopausal and climacteric symptoms, based on the PSQI scale, 124 women (32.2%) were classified as “good sleepers”, and 261 women (67.8%) as “bad/poor sleepers”. A positive relationship was observed between sleep scale scores and the overall menopause score along with its various domains. Women identified as having poor sleep quality exhibited higher (worse) scores on the menopause symptom scale [19]. Yisma et al. analyzed 226 perimenopausal and postmenopausal women in Ethiopia, with an average age of 40.4 years old. 39.1% of perimenopausal women and 70.7% of postmenopausal women experienced difficulty falling asleep. Postmenopausal women had elevated scores in the somatic, psychological, and urogenital subscales of the MRS when compared to perimenopausal women. The reported severity of symptoms varied, with 8.4% of the total MRS scores, 1.3% of the somatic scores, 10.6% of the psychological scores, and 8.4% of the urogenital scores indicating high severity [20].
Hachul et al. performed an epidemiologic study in São Paulo, Brazil. The study comprised 535 women, 339 of whom were in the premenopausal stage, 53 in the early postmenopausal phase, 118 in the late postmenopausal phase, and 25 were undergoing treatment with hormone therapy or isoflavone compounds. When comparing objective sleep patterns between premenopausal and postmenopausal women in an analysis unadjusted except for age, the results showed that postmenopausal women had an increase of deep sleep (stage N3 [%]) and apnea/hypopnea index (AHI) as well as a decrease in rapid eye movement sleep stage (REM [%)]), and basal, mean and minimum arterial oxygen saturation (SaO2 [%]) compared to premenopausal women. The unadjusted analysis within the postmenopausal group (early vs. late) showed that women in early postmenopause had increased stage N3 (%) and AHI when compared to late postmenopause women [21].
Poor sleep quality in menopausal women does not have to be associated with vasomotor symptoms, the prevalence of which usually increases in menopausal transition. In a Chinese study in a group of 1088 Chinese women without vasomotor symptoms, 353 of whom were postmenopausal, the researchers presented a correlation between menopausal status and self-reported poor sleep quality in women without vasomotor symptoms. Postmenopausal women had significantly higher average global PSQI scores (8.0 vs. 6.1) and a greater prevalence of poor sleep quality (73.1% vs. 60.8%) compared to premenopausal women. The results of the study indicated that postmenopausal women, even those without vasomotor symptoms, reported significantly poorer sleep quality than premenopausal women [22].
Additionally, menopausal transition correlates with a decrease in total sleep time (TST) [23]. Kalleinen et al. stated in their study that the total length of night sleep for premenopausal women was 404.9 minutes, for postmenopausal women 384.7 minutes, and for younger women was 448.2 minutes [23].
The majority of studies show that postmenopausal women report higher scores for “difficulty sleeping” than premenopausal women [24]. Lu et al. performed a study in a group of 197 Arabic women aged 45–65 years old, having used the menopause-specific quality of life (MENQOL) questionnaire to collect data on sociodemographic characteristics and menopausal symptoms. Difficulty sleeping was reported by 46.3% of premenopausal women, 71.4% of perimenopausal women, and 72.9% of postmenopausal women [24]. Adversely, postmenopausal women older than 65 years old had lower scores in “difficulty sleeping“ than younger postmenopausal women [25].
During a menopausal transition, estradiol levels decline and follicle-stimulating hormone (FSH) concentration rises accordingly with menopausal status. In midlife women, more sleep disturbances are observed in the luteal phase of the ovary cycle, compared to the follicular phase, whether or not women suffer from insomnia [26] (Tables 1, 2). Increase in prevalence of vasomotor symptoms during menopausal transition and their impact on sleep quality
The majority of studies show that women during menopausal transition experience multiple VMS [27, 28]. Blümel et al. conducted a study in a group consisting of 8,373 women aged 40–59 years old and discovered that the incidence of VMS, regardless of their severity, noticeably rose from one stage of menopause to the next, reaching a peak in women who were in the early postmenopausal phase (68.5%), before slightly declining in the late postmenopausal group (60.6%). Even after 10–15 years since the onset of menopause, over half (63.6%) of the women continued to experience VMS. Among premenopausal women, 5.5% reported severe VMS, with the rate doubling in perimenopausal women. The study found that experiencing VMS at any degree increased the likelihood of higher total, somatic (inter alia sleeping problems), psychological, and urogenital MRS scores [5]. Sleeping problems are one of the main complaints after menopause [29]. The severity of VMS is shown to decrease with age after menopause [25].
In the Minnesota Green Tea Trial, a study about the quality of life of postmenopausal women, the researchers used MENQOL to evaluate a range of symptoms experienced by postmenopausal women between the ages of 50–70 years old. It was discovered that women aged 65 and above reported lower scores in terms of “feeling tired or worn out,” experiencing “difficulty sleeping,” and a “lack of energy” compared to all other age groups, with the differences being statistically significant (p ≤ 0.003). Women aged 50–54.9 years old indicated having experienced more intense night sweats, sweating, and hot flashes than those from higher age groups, the results have been statistically significant (p ≤ 0.001 for night sweats and sweating, and p < 0.001 for hot flashes) [25]. Syed Alwi et al. demonstrated that VMS significantly affected the quality of life, most notably among perimenopausal women, who showed the greatest decline in life quality, followed by postmenopausal and premenopausal women [6]. Differences in difficulty falling asleep were associated with menopausal status, with 19 premenopausal women (31.6%) who reported sleep issues, 77 perimenopausal women (67.5%), and 78 postmenopausal women (76.5%) who experienced difficulty sleeping. Similar results were found by Waidyasekera et al., who indicated that hot flashes, sleep disturbances, and joint/muscle discomfort were more common among postmenopausal women compared to premenopausal women, with statistical significance (p < 0.05) [30] (Table 3).

The most common sleep disorders in the period of menopausal transition

Mazzotti et al. in their study provided insight into how OSA varied across different age groups of women, based on data from the apnea positive pressure long-term Efficacy Study. 382 women were divided into two groups, those aged ≤ 45 years old and those aged ≥ 53 years old. Younger women (≤ 45 years) had higher body mass index (BMI), Epworth sleepiness scale, and Hamilton rating scale for depression scores, but lower morningness-eveningness questionnaire scores compared to older women (≥ 53 years). Polysomnography findings indicated that women in the younger age group displayed increased TST and sleep efficiency (SE), yet they experienced comparable sleep onset latency and AHI levels to those observed in older women. Older women had lower AHI and higher TST and SE compared to older men, indicating age-related variations in OSA characteristics [11]. Krüger et al. examined the connection between menopause and OSA in a population-based sample. They found a significant association between menopause and the AHI, which indicated that postmenopausal women had a substantially higher risk of OSA (OR 2.82). The mean AHI of postmenopausal women (M = 10.3, SD = 12.9) was higher than that of premenopausal women (M = 1.9, SD = 3.3), Cohen’s d = 0.89 [8]. Krüger et al. focused on assessing the occurrence of OSA and its risk factors among women after menopause. The study defined postmenopausal women as those aged over 50 years. Symptoms of OSA were considerably more frequent in women over the age of 50, indicating a significant rise in the risk of developing OSA after menopause [8]. Heart rate variability, BMI, and demographic features also could potentially be used to indicate a group of patients at higher risk of OSA [31].
The prevalence of sleep-disordered breathing (SDB) is higher in postmenopausal women than before menopause. Heinzer et al. examined the prevalence of SDB and its associated comorbidities in different groups: men, premenopausal women, and postmenopausal women. The study included 1024 men and 1097 women, 328 out of whom were premenopausal. The highest prevalence of SDB was observed in men and postmenopausal women, specifically when based on AHI. Apnea/hypopnea index of > 5/h, > 15/h, > 20/h, and ≥ 30/h was found to have been as follows: in postmenopausal women 71.6%, 29.4%, 20.7%, and 10.1%, respectively, and in premenopausal women: 35.1%, 8.6%, 3.3%, and 1.3%, respectively [4]. Koo et al. analyzed a group of 1540 patients, with 147 women meeting the criteria for REM SDB. Patients with OSA had lower levels of estrogens and progesterone than patients without OSA [32]. Apnea/hypopnea index in postmenopausal women was significantly higher than in those experiencing menstruation, with NREM AHI in postmenopausal women vs. younger women of: 4.6 vs. 3.6 [32]. The HypnoLaus study in the prevalence of SDB in the general population unveiled interesting insights, especially concerning women’s menopausal status. The study group included 2121 individuals, 1024 men and 1097 women – primarily those aged 40 years and older – and targeted a demographic inclusive of premenopausal, perimenopausal, and postmenopausal women. The analysis showed a stark difference in the median AHI based on menopausal status, where premenopausal women recorded significantly lower median AHI values (2.8 events per hour) in comparison to postmenopausal women (8.7 events per hour) [33]. Mirer et al. analyzed a group of 219 women aged 38–62 years old, with a collective/collection of 1667 sleep studies. The analysis showed that AHI levels were higher by 21% in perimenopause and by 31% in postmenopause, compared to the premenopausal participants. Additionally, the study showed that with each succeeding year of postmenopause, there was a corresponding 4% increase in the AHI, establishing a direct relationship where every additional year in menopause correlated with a 4% increase in AHI [34].
Menopausal transition was found to increase the frequency of snoring. Zhou et al. aimed to investigate the link between the frequency of self-reported snoring and body composition among Chinese women going through the (peri-post) menopausal phase, along with examining various metabolic indicators. This study involved 715 women aged 40–67 years old from the Menopause Clinic at Shanghai Sixth People’s Hospital. The results of the study found an independent association between the volume of fat mass segments, and regular snoring during the menopausal transition phase, but not during postmenopause [35]. The study analyzing the prevalence of snoring included 2151 females of more than 20 years of age. The prevalence of snoring was found to have been considerably higher in women experiencing menopausal symptoms compared to those without (p = 0.021, odds ratio = 1.629), with a statistically significant increase after the age of 50, furthermore increased in women with the presence of menopausal symptoms [12]. Studies show that premenopausal women snore less than postmenopausal women [18]. Hai-Bin et al. analyzed 33 677 women aged 30–79 years old and found that in the group of premenopausal women, only 14.11% were frequent snorers, in contrast to 23.27% of the postmenopausal women (p < 0.001) [18] (Table 4).

Prevalence and severity of sleep disorders according to ethnicity and stages of menopause

The Study of Women’s Health Across the Nation, on 3045 women, included women of European descent, African American, Chinese, Japanese, and Hispanic individuals, aged 42–52 years old, who were premenopausal or in the early perimenopausal stage at the start of the study. The study explored the prevalence and severity of sleep disorders in different ethnic groups and at different stages of menopause, revealing nuanced interactions between race/ethnicity, menopausal status, and sleep difficulties. No significant differences were found in trouble falling asleep among different ethnic groups, indicating it is a universal challenge. White women reported waking up several times during the night significantly more than other groups, with the least prevalence of waking up at night in the group of Hispanic women. There was a higher incidence of early morning awakenings in the group of women of European descent when compared to Hispanic women across all models, and marginally lower compared to Chinese women. Hispanic women had a significantly lower incidence of early morning awakenings than both African American and Chinese women.
The study also delved into how these sleep disturbances interacted with menopausal status and VMS across different ethnic groups. The impact of menopausal status on sleep disturbances did not significantly vary across ethnic groups after having adjusted the model for hormone therapy users, surgically menopausal women, and certain geographical participants. Yet, the interaction between VMS and ethnicity proved significant for early morning awakening, indicating that the odds of experiencing early morning awakenings escalated with the frequency of VMS across all groups. This effect was notably stronger in Chinese and Japanese women with high VMS frequency, while Hispanic women showed a consistent odds ratio across different VMS frequencies. Significant differences were observed when comparing White women to other groups in specific VMS frequencies: Hispanic women with no VMS were less likely, and Chinese women with high VMS frequency were more likely, to have reported early morning awakenings. These findings emphasize the complex relationship between ethnicity, menopausal status, and sleep disorders, suggesting that the experience of menopause-related sleep difficulties is influenced by both biological symptoms and cultural or genetic background [2].
Kripke et al. examined a group of 98 705 postmenopausal women, predominantly women of European descent (84%), with smaller proportions of African (9%), Hispanic (3%), and other minority groups (including Asian, Pacific Islander, Native American, and others – 4%). The women’s ages ranged 50–79 years old and the study revealed diverse sleep patterns and problems. African women, across all age groups, attained 0.45 hours less sleep than White women, with Hispanic and other minority groups having reported intermediate sleep duration. Across all ages, African and Hispanic women were more likely to experience either very short sleep durations (less than 7 hours) or very long sleep durations (longer than 10 hours), while women in the “other ethnic minorities” group, reported less frequently long sleep duration but more often short sleep duration. When examining sleep symptoms by ethnicity, all symptoms showed significant differences (p < 0.001) among the four groups. Women from the minority group experienced more difficulties falling asleep, tended to fall asleep during quiet activities, napped more during the day, and snored more. However, they reported waking up multiple times during the night less frequently and using sleep aids less often than White women. When adjusted for obesity, African women’s higher rates of snoring and napping were not significant, suggesting that obesity might have been a confounding factor. Additionally, sleep complaints showed a U-shaped relationship with sleep duration, indicating that both very short and very long sleep durations were associated with more sleep-related issues compared to intermediate sleep durations. Specifically, optimum sleep duration for minimizing sleep complaints varied for different sleep disorders: 7 hours for the least use of sleep aids, daytime napping, and snoring; 8 hours for minimum trouble falling asleep and waking up several times; and 9 hours for the least waking up earlier than planned and trouble returning to sleep. These findings emphasize the complex interplay between ethnicity, menopausal status, and sleep quality, highlighting that sleep disorders are influenced by a combination of genetic and cultural factors among postmenopausal women [36].
Studies show that insomnia is more common in older adults and women of European descent [37] Madaeva et al. sought to understand how sleep disorders manifested in white and Asian women aged 45–60 years old. A total of 542 women participated, having undergone evaluation by obstetrician-gynecologists, clinical examinations, and reviews of their medical histories. Diagnoses of insomnia and obstructive sleep apnea syndrome (OSAS) were determined through specialized sleep questionnaires and polysomnography. The findings revealed that sleep disorders were comparably prevalent among both groups, with 61.2% of White women in perimenopause and 65.5% in postmenopause who experienced sleep issues. For Asian women, these figures were 63.5% in perimenopause and 72.9% in postmenopause. Women of European descent frequently reported trouble falling asleep (69.4%) and difficulties with morning awakenings (63.5%) during perimenopause, whereas postmenopausal White women often experienced nightly awakenings (83.5%) and OSAS (48.9%). Interestingly, Asian women’s sleep disorder complaints did not vary between perimenopause and postmenopause phases, with the most common issue being frequent night-time awakenings (69.5% in perimenopause and 76.9% in postmenopause). The study highlighted ethnic differences in sleep complaints primarily during perimenopause, with Asian women exhibiting lower SE and alterations in REM sleep compared to White women. Additionally, Asian women had higher AHI and lower oxygen saturation levels than women of European descent [38]. Other data suggest that Indian women experience fewer VMS than White women, with only 34% experiencing hot flashes and 31% dealing with night sweats [39] (Tables 5, 6).

How to treat menopausal sleep disorders

There are studies suggesting that the Paleolithic diet reduces OSA prevalence in postmenopausal women with obesity. The level of body adiposity is one of the most important predictors of OSA [40]. Franklin et al. investigated possible treatments for menopausal sleep disorders, particularly focusing on the impact of diet on sleep apnea severity in postmenopau- sal women with obesity. Initially, the average AHI in the study group was 11.6. The research focused on evaluating the impact of a Paleolithic diet vs. a low-fat diet on weight loss in postmenopausal women with a BMI greater than 30. Findings revealed that participants adhering to the Paleolithic diet experienced a higher average weight loss of 7.2 kg, while the control group following the low-fat diet lost an average of 3.9 kg. This weight loss disparity was statistically significant, with a p-value of less than 0.021. The reduction in weight in the Paleolithic diet group was correlated with a decrease in AHI (r = 0.38, p = 0.034), indicating an improvement in sleep apnea symptoms. However, this correlation was not observed in the control group. Notably, a weight reduction of more than 8 kg was required to observe a reduction in AHI in the Paleolithic diet group. The study concluded that a weight loss of at least 8 kg was necessary for a reduction in sleep apnea symptoms in postmenopausal women with obesity. The Paleolithic diet proved more effective for weight loss compared to a conventional low-fat diet, and the decrease in sleep apnea severity was directly linked to the extent of weight loss within the Paleolithic diet group [10].
Oral combined 17-estradiol/progesterone therapy is known to reduce the prevalence of VMS and improve the quality of life and sleep in postmenopausal women. Mirkin et al. investigated how TX-001HR, a combined oral dose of 17-estradiol and progesterone (E2/P4) affected the prevalence of VMS and quality of both life and sleep among postmenopausal women aged 40–65 years old, who experienced moderate to severe VMS. The study’s findings, drawn from comparisons between the outcomes for 591 women treated with varying doses of E2/P4 and 135 women receiving a placebo, indicated significant associations across all analyzed models. The improvements in MENQOL scores, both overall and specifically in the VMS domain, closely correlated with reductions in the frequency and severity of VMS after 12 weeks of treatment, with all correlations marked by high statistical significance (p < 0.001). This pattern was mirrored in the sleep quality outcomes measured by the Medical Outcomes Study-Sleep questionnaire [41].
Avoiding stress and lowering cortisol levels can improve overall sleep quality. De Zambotti et al. examined the impact of acute stress from the Trier social stress task on sleep in perimenopausal women, comparing those with and without insomnia. Results showed that acute stress increased cortisol levels, perceived tension, heart rate, and reduced relaxation in both groups. However, normalization in relaxation levels during the latter part of the night was observed only in the control group when compared to the group with insomnia. Stress delayed REM sleep onset in both groups, but notably increased electroencephalography arousal during sleep in the insomnia group alone, indicating heightened sensitivity to stress [42].

Limitations of the study

Generalizability

Focus on specific populations (women of European descent and Asians) may not fully represent the diversity within these broad categories or capture the experiences of women from other ethnic backgrounds not included in the analyzed studies.

Cultural and environmental factors

While the review attempted to account for ethnic diversity, it may not fully encompass the wide range of cultural, environmental, and lifestyle factors that influence menopause symptoms and sleep quality across different societies.

Subjective measurements

The reliance on self-reported symptoms and quality- of-life assessments can introduce bias as individual perceptions and cultural norms might influence how symptoms are reported and interpreted.

Temporal and hormonal considerations

The review might not fully address how changes over time in hormonal levels and menopausal status could dynamically influence sleep quality, requiring longitudinal studies for a more comprehensive understanding.

Lack of hormonal data

Hormonal changes, including a decline in estrogen levels and an increase in FSH, are recognized as key contributors to menopause-related sleep disturbances. However, the lack of consistent measurement and inclusion of these hormonal fluctuations in all studies limits the ability to establish definitive connections between specific hormonal profiles and sleep quality.

Temporal and longitudinal data gaps

The majority of studies included in this review used cross-sectional designs, which capture a single point in time rather than following individuals over a period to observe changes. As a result, they do not provide insight into how menopausal transitions and sleep disturbances develop or progress. To establish causal relationships and better understand the trajectory of symptoms, longitudinal studies are essential.

Bias toward medicalized and dietary treatments

The review primarily highlights studies that focus on pharmaceutical or dietary treatments, while giving less attention to non-medical or alternative approaches, such as lifestyle modifications or culturally tailored strategies.

Limited exploration of comorbidities

Factors like obesity, cardiovascular diseases, and mental health issues, which are known to impact sleep, were not consistently accounted for in the studies. This lack of control could distort the observed links between menopause and sleep disturbances.
Future research that overcomes these limitations could offer a deeper understanding of how menopausal status, ethnicity, and sleep quality interact. These insights are essential for creating personalized interventions that better support the health and well-being of diverse populations.

Conclusions

The relationship between menopausal status, ethnic background, and sleep quality, emphasizes the significant physiological changes women undergo during menopause and the diverse ways these changes manifest across different populations. Menopausal symptoms, including sleep disturbances, vary significantly across different populations, suggesting the influence of genetic, environmental, lifestyle, and cultural factors on the menopausal experience. Menopause, particularly due to symptoms like hot flashes, night sweats, and hormonal fluctuations, profoundly affects sleep quality. This impact is further complicated by the interaction of ethnic and cultural differences. A deeper understanding of how menopausal transitions affect women from different cultural and social backgrounds is crucial for finding optimum ways of treating different sleep disorders associated with menopause in diversified groups of patients. This knowledge can aid in developing targeted interventions adjusted for the unique needs of women during this psychologically and emotionally difficult life stage. There is an existing gap in comprehensive studies examining the full scope of menopausal impact on sleep quality across diverse ethnic groups. Future research should aim to include a wider range of populations, investigate various management strategies beyond dietary and hormonal treatments, and employ longitudinal study designs for a more detailed understanding. Menopause plays a significant but complex role in affecting sleep quality among women from different ethnic backgrounds. It calls for a more nuanced, culturally informed approach in both research and clinical practice to better support women navigating the challenges of menopause.
The findings of this review align with prior research demonstrating a clear increase in sleep disturbances during the menopausal transition. For instance, Blümel et al. reported that insomnia prevalence progressively rises with advancing menopausal stages, from 49.6% in women aged 40–44 years to 75.8% in those aged 55–59 years [3]. These findings underscore the impact of hormonal changes on sleep quality. Similarly, Tom et al. found that the risk of moderate sleep difficulties increased by 35% during perimenopause and by 48% during postmenopause, with severe difficulties nearly tripling (OR 2.84) in postmenopausal women compared to controls.
This review also highlights significant variations in symptom prevalence among ethnic groups, emphasizing the roles of cultural, genetic, and environmental factors. For example, Madaeva et al. demonstrated that while sleep disorders were prevalent in both women of European descent and Asian women, Asian women exhibited lower SE and AHI scores. Such findings stress the importance of culturally tailored healthcare approaches. While many studies link poor sleep quality to VMS such as night sweats and hot flashes, this review also identifies substantial sleep disturbances in women without VMS. Hung et al. found that postmenopausal women without VMS reported poorer sleep quality compared to premenopausal women, as evidenced by PSQI scores (8.0 vs. 6.1). This reinforces the multifactorial nature of menopause-related sleep disturbances, which extend beyond classic VMS-related complaints [22].

Disclosures

1. Institutional review board statement: Not applicable.
2. Assistance with the article: None.
3. Financial support and sponsorship: None.
4. Conflicts of interest: None.

References