Abstract
Objectives:
To examine the prevalence and risk factors of menopausal symptoms in middle-aged Chinese women.
Methods:
A cross-sectional, community-based study recruited 6,745 women aged 40 to 55 years in the eastern, central, and western regions of China during 2018. Menopausal status was categorized into reproductive stage (defined as regular menstruation or subtle changes in menstrual cycle characteristics), menopausal transition (the beginning of a persistent difference of 7 d in the length of consecutive cycles, or the last menstruation having occurred no more than 12 mo), or postmenpause (the end of the 12 mo period of amenorrhea) according to the Stages of Reproductive Aging Workshop classification. Menopausal symptoms were determined by the modified Kupperman Menopausal Index (KMI) questionnaire and considered nonmenopausal symptoms (total KMI score<15) and menopausal symptoms (total KMI score≥15). Demographic, lifestyle, physical, and menopausal characteristics were collected by face-to-face interviews. Logistic regression models were used to identify factors associated with the risk of menopausal symptoms.
Results:
Among all participants, the mean age was 46.9 years, and 15.7% (1,001/6,364) of participants reported experiencing menopausal symptoms. The prevalence of menopausal symptoms was 9.3% (303/3,256), 23.9% (293/1,227), and 21.5% (405/1,881) in the reproductive stage, menopausal transition, and postmenopausal stage, respectively. Overall, the three most prevalent menopausal symptoms were insomnia (44.7%), fatigue (40.4%), and mood swings (37.2%). The multivariable logistic regression model showed that menopausal status, residence, nulliparity, and chronic diseases were associated with the risk of menopausal symptoms (all P < 0.05). Women during menopausal transition (OR = 2.66, 95% CI: 2.21-3.20) or postmenopause (OR = 2.26, 95% CI: 1.82-2.80) had significantly increased risk of menopausal symptoms compared with those in the reproductive stage.
Conclusions:
Menopausal status, residence, nulliparity, and chronic diseases were associated with menopausal symptoms in middle-aged Chinese women.
Keywords: Menopausal symptoms, Menopause, Perimenopause, Postmenopause, Risk factors
Menopause is a physiological event for women caused by failure of ovarian follicular function that leads to decreased secretion of ovarian hormones estrogen and progesterone.1 The average age at natural menopause was reported to be 48.8 years globally, ranging from 47.2 years in Latin America to 51.3 years in Australia.2 With the rise in life expectancy, women spend more than one-third to one-half of their lifetime beyond the menopausal transition.3 Therefore, attention to the process of menopause may contribute to improving menopause-related health conditions for middle-aged women. Prior research indicated that women during menopausal transition were more likely to experience various menopause-related symptoms including central nervous system-related disorders, urogenital and skin atrophy, sexual dysfunction, and weight, metabolic, cardiovascular, and musculoskeletal changes.4-7 Although the majority of menopausal symptoms are not life-threatening, they have an adverse influence on the social and work lives, and the quality of life of middle-aged women.4,8
Previous epidemiologic studies have suggested that the prevalence of menopausal symptoms varies considerably among women of different ethnicities.4 For example, White women reported a high prevalence of vasomotor symptoms such as hot flashes and night sweats, while Asian women mostly suffered from physical and somatic symptoms such as headaches, body or joint pains, and sleeping problems.9,10 The Pan-Asian Menopause study investigated the prevalence of 18 menopausal symptoms in 9 Asian countries and suggested that the percentages of overall and individual menopausal symptoms differed among the ethnic groups, with the lowest overall rates reported by Indonesian women and the highest for Vietnamese women.10 In addition, several factors including menopausal status, socioeconomic status, lifestyle factors, and chronic conditions were identified to be associated with menopausal symptoms.4,11,12 An earlier longitudinal cohort study based on US women suggested that menopausal status exhibited the strongest association with vasomotor symptoms, followed by education background, anxiety symptoms, and smoking.11 Another study indicated that increased abdominal adiposity was associated with elevated odds of menopausal symptoms.12 Previous evidence for menopausal symptoms assessed by validated instruments mainly accumulated from Western countries; however, few large-scale epidemiological studies focused on Asian countries including China.
Therefore, the aim of the present study was to describe the prevalence of menopausal symptoms assessed by the Kupperman Menopausal Index (KMI) according to menopausal status in middle-aged Chinese women, and to examine the association of menopausal status and other influential factors with menopausal symptoms.
METHODS
Study design and participants
The National Survey of Women's Health is a cross-sectional, community-based study of women residing in three socioeconomic regions of China: eastern (Jiangsu and Shandong provinces), central (Hunan and Anhui provinces), and western (Shanxi and Sichuan provinces). Details of this study have been described elsewhere.13 Briefly, one urban and one rural area were selected as investigation sites in each province, and we recruited women aged 10 to 70 years by a multistage stratified random cluster sampling at each investigation site. Face-to-face interviews were conducted to collect information on demographic characteristics, medical history, menopausal status, and symptoms (only collected in women aged 40-70 y) by using a structured questionnaire. Among 6,745 participants aged 40 to 55 years, the present analysis was limited to 6,364 participants. Those meeting the following criteria were excluded: incomplete data collection for menopausal symptoms (n = 69); women who had gynecological tumors (n = 72) or breast cancer (n = 25); women who took estrogen in the past 6 months (n = 60); and women who were in artificial menopause (n = 200). All participants provided written informed consent, and the study was approved by the Ethical Review Committee of the Chinese Center for Disease Control and Prevention.
Measurements
According to the 2011 Stages of Reproductive Aging Workshop + 10 criteria,14 menopausal status was categorized into 1) reproductive stage, defined as regular menstruation, or subtle changes in menstrual cycle characteristics; 2) menopausal transition, defined as the beginning of a persist difference of 7 days in the length of consecutive cycles, or the last menstruation having occurred no more than 12 months; and 3) postmenopause, defined as the end of the 12 month period of amenorrhea.
The modified KMI in the Chinese version, which has been validated and widely used in China, was utilized to describe the severity and intensity of menopause symptoms.15 All of the following definitions and criteria were recommended by the Chinese Obstetrics and Gynecology.16 The KMI consists of 13 items including hot flashes, paresthesia, insomnia, mood swings, depression, dizziness, fatigue, arthralgia and myalgia, headache, palpitations, skin formication, sexual problems, and urinary tract infection. A scale ranging from 0 to 3 points is utilized to assess the severity of each item: 0, no symptoms; 1, mild symptoms; 2, moderate symptoms; and 3, severe symptoms. Each item was scored individually and multiplied by its weighting factor: hot flashes scored 4 points; paresthesia, insomnia, mood swings, sex life, and urinary tract infection scored 2 points each, and all other symptoms scored 1 point each. According to the total score of KMI that was calculated as the sum of all items by the weighting factors, participants were classified into two groups: nonmenopausal symptoms (total KMI score <15) and menopausal symptoms (total KMI score ≥15).16 Further, the severity of menopausal symptoms was considered mild (15≤ total KMI score <35) and moderate-to-severe (total KMI score ≥ 25).16 Cronbach's α was 0.87 in the present study.
Assessment of covariates
The interviewer-administered structured questionnaire was used to assess the information of all participants, as well as anthropometric parameters such as height, weight, and waist circumference. Covariates included age, residence, education, employment status, marital status, average monthly household income, drinking, smoking, regular physical activity, body mass index (BMI) categories, parity, and chronic diseases. Regular physical activity was defined as light to vigorous exercise of at least 20 minutes each time and at least three times per week. BMI was calculated as the weight in kilograms divided by the square of height measured in meters, and classified into four groups according to the Chinese standard:17 underweight (BMI <18.5 kg/m2), normal weight (18.5 kg/m2 ≤ BMI <24 kg/m2), overweight (24 kg/m2 ≤ BMI <28 kg/m2), and obese (BMI ≥ 28 kg/m2).
Statistical analysis
Demographics characteristics were presented as numbers and frequency distributions for categorical variables, or median and interquartile range for continuous variables, and were compared using the chi-square test or Mann-Whitney U test. Generalized linear models were used to estimate mean KMI scores adjusted for age, and we further adjusted for residence, education, employment status, marital status, average monthly household income, and study sites. We first performed univariate logistic regression models to assess the association of menopausal status, and demographic, lifestyle, and physical factors with the presence of menopausal symptoms. Then, multivariate logistic regression models were conducted using variables associated with menopausal symptoms at the P≤0.2 level in each univariate model to evaluate the independent effect of these potential variables on menopausal symptoms. Further, we conducted univariate and multivariate logistic regression models to examine the association of menopausal status with each individual menopausal symptom. In the multivariate models, we adjusted for age, residence, education, employment status, marital status, average monthly household income, drinking, smoking, regular physical activity, BMI categories, parity, chronic diseases, and study sites. The reproductive stage group was used as the reference groups. Analyses were conducted using SAS software version 9.4 (SAS Institute, Cary, NC). All P values are two-sided, and a 0.05 level was used to declare significant differences.
RESULTS
Characteristics of study participants
Among 6,364 women aged 40 to 55 years, the mean age was 46.9 years, and 15.7% (1,001/6,364) of participants reported to experience menopausal symptoms based on the total KMI score. Table 1 shows demographic characteristics of study participants according to menopausal status. Women during menopausal transition were more likely to reside in rural areas, and to drink and currently smoke, and less likely to be married, and had higher rates of overweight and obesity (all P < 0.05). The postmenopausal women were older, and more likely to have lower levels of education and lower average monthly household income, and less likely to be employed and nulliparous, and had a higher prevalence of chronic diseases (all P < 0.05).
TABLE 1.
Characteristics of participants by menopausal status
| Total | Reproductive stage | Menopausal transition | Postmenopause | P value | |
| Participants, n (%) | 6,364 | 3,256 (51.1) | 1,227 (19.3) | 1,881 (29.6) | |
| Age, y, median (IQR) | 47 (43, 50) | 44 (42, 47) | 47 (44, 49) | 52 (49, 54) | <0.001 |
| Residence | 0.005 | ||||
| Urban | 3,159 (49.6) | 1,650 (50.7) | 558 (45.5) | 951 (50.6) | |
| Rural | 3,205 (50.4) | 1,606 (49.3) | 669 (54.5) | 930 (49.4) | |
| Education | <0.001 | ||||
| High school and below | 5,711 (89.7) | 2,820 (86.6) | 1,110 (90.5) | 1,781 (94.7) | |
| College or graduate school | 653 (10.3) | 436 (13.4) | 117 (9.5) | 100 (5.3) | |
| Employment status | <0.001 | ||||
| Unemployed/retired | 1,117 (17.6) | 493 (15.1) | 200 (16.3) | 424 (22.5) | |
| Employed | 5,247 (82.4) | 2,763 (84.9) | 1,027 (83.7) | 1,457 (77.5) | |
| Marital status | <0.001 | ||||
| Married | 5,881 (92.4) | 3,069 (94.3) | 1,109 (90.4) | 1,703 (90.5) | |
| Single/divorced/widowed | 483 (7.6) | 187 (5.7) | 118 (9.6) | 178 (9.5) | |
| Average monthly household income, RMB | <0.001 | ||||
| <5,000 | 4,145 (65.1) | 1,918 (58.9) | 827 (67.4) | 1,400 (74.4) | |
| 5,000-10,000 | 1,953 (30.7) | 1,182 (36.3) | 355 (28.9) | 416 (22.1) | |
| >10,000 | 266 (4.2) | 156 (4.8) | 45 (3.7) | 65 (3.5) | |
| Drinking | 0.003 | ||||
| No | 5,648 (88.8) | 2,873 (88.2) | 1,068 (87.0) | 1,707 (90.8) | |
| Yes | 716 (11.2) | 383 (11.8) | 159 (13.0) | 174 (9.2) | |
| Smoking | 0.040 | ||||
| Not current smoker | 6,188 (97.2) | 3,175 (97.5) | 1,180 (96.2) | 1,833 (97.5) | |
| Current smoker | 176 (2.8) | 81 (2.5) | 47 (3.8) | 48 (2.5) | |
| Regular physical activity | 0.533 | ||||
| No | 3,857 (60.6) | 1,957 (60.1) | 760 (61.9) | 1,140 (60.6) | |
| Yes | 2,507 (39.4) | 1,299 (39.9) | 467 (38.1) | 741 (39.4) | |
| BMI, kg/m2 | <0.001 | ||||
| <18.5 | 559 (8.8) | 210 (6.4) | 108 (8.8) | 241 (12.8) | |
| 18.5-23.9 | 3,460 (54.3) | 1,955 (60.0) | 606 (49.4) | 899 (47.8) | |
| 24-27.9 | 1,779 (28.0) | 845 (26.0) | 385 (31.4) | 549 (29.2) | |
| ≥28 | 566 (8.9) | 246 (7.6) | 128 (10.4) | 192 (10.2) | |
| Parity | <0.001 | ||||
| 0 | 130 (2.0) | 76 (2.3) | 30 (2.4) | 24 (1.3) | |
| 1-2 | 5,614 (88.2) | 2,958 (90.9) | 1,078 (87.9) | 1,578 (83.9) | |
| ≥3 | 620 (9.8) | 222 (6.8) | 119 (9.7) | 279 (14.8) | |
| Chronic diseases | <0.001 | ||||
| No | 5,254 (82.6) | 2,923 (89.8) | 963 (78.5) | 1,368 (72.7) | |
| Yes | 1,110 (17.4) | 333 (10.2) | 264 (21.5) | 513 (27.3) |
Values are median (IOR) or n (%).
The prevalence of menopausal symptoms by menopausal status
The prevalence of menopausal symptoms was 9.3% (303/3,256), 23.9% (293/1,227), and 21.5% (405/1,881) in the reproductive stage, menopausal transition, and postmenopausal stage, respectively (Fig. 1). 7.3% (238/3,256), 18.4% (226/1,227), and 15.6% (294/1,881) of women reported mild menopausal symptoms in the reproductive stage, menopausal transition and postmenopausal stage, respectively, while 2.0% (65/3,256), 5.5% (67/1,227), and 5.9% (111/1,881) reported moderate-to-severe menopausal symptoms in the reproductive stage, menopausal transition, and postmenopausal stage, respectively (Fig. 1).
FIG. 1.
Percentage of menopausal symptoms by menopausal status.
Table 2 illustrates the proportion of each menopausal symptom by menopausal status. Among all participants, the three most prevalent menopausal symptoms were insomnia (44.7%), fatigue (40.4%), and mood swings (37.2%). In women during menopausal transition, the three most common menopausal symptoms were insomnia (50.8%), fatigue (46.4%), and mood swings (44.8%), whereas insomnia (53.8%), fatigue (44.3%), and headache (42.9%) were the three most bothersome symptoms among those in postmenopause. Overall, women during menopausal transition and postmenopause had a higher likelihood of each individual menopausal symptom than those in the reproductive stage (all P < 0.05, Table 2).
TABLE 2.
Individual menopausal symptoms by menopausal status
| Total (n = 6,364) | Reproductive stage (n = 3,256) | Menopausal transition (n = 1,227) | Postmenopause (n = 1,881) | P value | |
| Hot flashes | <0.001 | ||||
| No | 4,532 (71.2) | 2,556 (78.5) | 784 (63.9) | 1,192 (63.4) | |
| Yes | 1,832 (28.8) | 700 (21.5) | 443 (36.1) | 689 (36.6) | |
| Paresthesia | <0.001 | ||||
| No | 4,854 (76.3) | 2,635 (80.9) | 856 (69.8) | 1,363 (72.5) | |
| Yes | 1,510 (23.7) | 621 (19.1) | 371 (30.2) | 518 (27.5) | |
| Insomnia | <0.001 | ||||
| No | 3,518 (55.3) | 2,044 (62.8) | 604 (49.2) | 870 (46.2) | |
| Yes | 2,846 (44.7) | 1,212 (37.2) | 623 (50.8) | 1,011 (53.8) | |
| Mood swings | <0.001 | ||||
| No | 3,997 (62.8) | 2,206 (67.8) | 677 (55.2) | 1,114 (59.2) | |
| Yes | 2,367 (37.2) | 1,050 (32.2) | 550 (44.8) | 767 (40.8) | |
| Depression | <0.001 | ||||
| No | 5,197 (81.7) | 2,785 (85.5) | 930 (75.8) | 1,482 (78.8) | |
| Yes | 1,167 (18.3) | 471 (14.5) | 297 (24.2) | 399 (21.2) | |
| Dizziness | <0.001 | ||||
| No | 4,340 (68.2) | 2,446 (75.1) | 755 (61.5) | 1,139 (60.6) | |
| Yes | 2,024 (31.8) | 810 (24.9) | 472 (38.5) | 742 (39.4) | |
| Fatigue | <0.001 | ||||
| No | 3,795 (59.6) | 2,090 (64.2) | 657 (53.6) | 1,048 (55.7) | |
| Yes | 2,569 (40.4) | 1,166 (35.8) | 570 (46.4) | 833 (44.3) | |
| Arthralgia and myalgia | <0.001 | ||||
| No | 4,355 (68.4) | 2,499 (76.8) | 771 (62.8) | 1,085 (57.7) | |
| Yes | 2,009 (31.6) | 757 (23.2) | 456 (37.2) | 796 (42.3) | |
| Headache | <0.001 | ||||
| No | 4,070 (64.0) | 2,261 (69.4) | 735 (59.9) | 1,074 (57.1) | |
| Yes | 2,294 (36.0) | 995 (30.6) | 492 (40.1) | 807 (42.9) | |
| Palpitations | <0.001 | ||||
| No | 4,991 (78.4) | 2,713 (83.3) | 892 (72.7) | 1,386 (73.7) | |
| Yes | 1,373 (21.6) | 543 (16.7) | 335 (27.3) | 495 (26.3) | |
| Skin formication | <0.001 | ||||
| No | 5,700 (89.6) | 3,004 (92.3) | 1,062 (86.6) | 1,634 (86.9) | |
| Yes | 664 (10.4) | 252 (7.7) | 165 (13.4) | 247 (13.1) | |
| Sexual problems | <0.001 | ||||
| No | 5,021 (78.9) | 2,843 (87.3) | 899 (73.3) | 1,279 (68.0) | |
| Yes | 1,343 (21.1) | 413 (12.7) | 328 (26.7) | 602 (32.0) | |
| Urinary tract infection | <0.001 | ||||
| No | 5,412 (85.0) | 2,853 (87.6) | 986 (80.4) | 1,573 (83.6) | |
| Yes | 952 (15.0) | 403 (12.4) | 241 (19.6) | 308 (16.4) |
P values were determined by using the chi-square tests.
Means of Kupperman Menopausal Index by menopausal status
The means for total KMI score progressively increased from reproductive stage to postmenopause after adjusting for age (P for trend < 0.001). After multiple adjustment, postmenopausal women had the highest total KMI score (mean = 8.38, 95% CI: 8.31-8.46), and women during menopausal transition had relatively higher total KMI score (mean = 7.28, 95% CI: 7.19-7.37), compared with women in reproductive stage (mean = 6.33, 95% CI: 6.27-6.38) (Fig. 2 and Supplementary Table 1).
FIG. 2.
Means and 95% CIs for total Kupperman index according to menopausal status. Adjusted for age, residence, education, employment status, marital status, average monthly household income, and study sites.
Association of menopausal status and demographic, lifestyle, and physical factors with menopausal symptoms
The unadjusted ORs (95% CIs) of potential associated factors by the presence of menopausal symptoms are shown in Table 3 and Supplemental Table 2. Age, menopausal status, residence, average monthly household income, BMI categories, parity, and chronic diseases were associated with menopausal symptoms in unadjusted models (all P < 0.05).
TABLE 3.
Association of risk factors with menopausal symptoms
| Univariable analysis | Multivariable analysis | |||
| P value | OR (95% CI) | P value | OR (95% CI) | |
| Age (per year) | <0.001 | 1.07 (1.05-1.08) | 0.627 | 1.01 (0.98-1.03) |
| Menopausal status | <0.001 | <0.001 | ||
| Reproductive stage | Ref | Ref | ||
| Menopausal transition | 3.06 (2.56-3.65) | 2.66 (2.21-3.20) | ||
| Postmenopause | 2.67 (2.28-3.14) | 2.26 (1.82-2.80) | ||
| Residence | <0.001 | 0.001 | ||
| Urban | Ref | Ref | ||
| Rural | 1.14 (1.02-1.28) | 1.29 (1.10-1.50) | ||
| Employment status | 0.140 | 0.183 | ||
| Unemployed/retired | Ref | Ref | ||
| Employed | 0.88 (0.74-1.04) | 0.88 (0.73-1.06) | ||
| Average monthly household income, RMB | <0.001 | 0.754 | ||
| <5,000 | Ref | Ref | ||
| 5,000-10,000 | 0.74 (0.63-0.86) | 0.98 (0.83-1.15) | ||
| >10,000 | 0.66 (0.45-0.97) | 0.86 (0.58-1.28) | ||
| Smoking | 0.081 | 0.309 | ||
| Not current smoker | Ref | Ref | ||
| Current smoker | 1.39 (0.96-2.02) | 1.22 (0.83-1.81) | ||
| BMI categories | 0.006 | 0.709 | ||
| Underweight (<18.5 kg/m2) | 1.35 (1.07-1.71) | 1.06 (0.82-1.36) | ||
| Normal weight (18.5-23.9 kg/m2) | Ref | Ref | ||
| Overweight (24-27.9 kg/m2) | 1.22 (1.04-1.43) | 1.09 (0.93-1.29) | ||
| Obese (≥28 kg/m2) | 1.32 (1.04-1.67) | 1.10 (0.86-1.41) | ||
| Parity | 0.009 | 0.087 | ||
| 0 | 1.53 (1.01-2.34) | 1.60 (1.02-2.50) | ||
| 1-2 | Ref | Ref | ||
| ≥3 | 1.31 (1.06-1.62) | 0.92 (0.73-1.16) | ||
| Chronic diseases | <0.001 | <0.001 | ||
| No | Ref | Ref | ||
| Yes | 2.25 (1.92-2.62) | 1.81 (1.53-2.14) | ||
Values are odds ratios (95% confidence intervals).
A multivariate logistic regression to evaluate independent associated factors for menopausal symptoms using potential variables (P≤0.2 in each univariate model) was presented in Table 3. In the multivariable model, menopausal status, residence, nulliparity, and chronic diseases were independently associated with the risk of menopausal symptoms (all P < 0.05). Women in menopausal transition (OR = 2.66, 95% CI: 2.21-3.20) and postmenopause (OR = 2.26, 95% CI: 1.82-2.80) were more likely to experience menopausal symptoms compared with those in the reproductive stage. Women residing in rural areas had greater odds of menopausal symptoms compared with those living in urban areas (OR = 1.29, 95% CI: 1.10-1.50). Nulliparous women were more likely to suffer from menopausal symptoms than those having one or two births (OR = 1.60, 95% CI: 1.02-2.50). Women who reported having chronic diseases had a higher likelihood of menopausal symptoms compared with those without chronic diseases (OR = 1.81, 95% CI: 1.53-2.14). Moreover, we further evaluated the interaction between age and menopausal status, residence, parity, and chronic diseases for the risk of menopausal symptoms. Results were generally consistent pertaining to associations of age with the risk of menopausal symptoms across different groups of menopausal status, residence, and chronic diseases, respectively, except for parity (data not shown).
We subsequently examined the association between menopausal status and individual menopausal symptoms (Supplementary Table 3). After adjustment for potential confounders, menopausal transition and postmenopausal stage were associated with higher risk for each individual menopausal symptom than during the reproductive stage.
DISCUSSION
In this large-scale cross-sectional study of Chinese women aged 40 to 55 years, 15.7% of women reported experiencing menopausal symptoms, and 9.3%, 23.9%, and 21.5% of women experienced menopausal symptoms during the reproductive stage, menopausal transition, and postmenopause, respectively. We observed that the three most bothersome menopausal symptoms were insomnia, fatigue, and mood swings. In addition, we also found that menopausal status, residence, nulliparity, and chronic diseases were associated with the risk of menopausal symptoms.
In this study, 15.7% of participants experienced menopausal symptoms assessed by the modified KMI, and 11.9% and 3.8% of women reported mild and moderate-to-severe menopausal symptoms, respectively. Several earlier epidemiologic studies conducted in different areas of China also examined the prevalence of menopausal symptoms. A previous cross-sectional study involving 1,054 middle-aged women in Zhejiang province, a southeast region of China, also used the modified KMI to measure the presence of menopausal symptoms and reported a prevalence of 21.6%.18 Another cross-sectional study performed in 9,939 women from Guangdong province located in Southern China indicated that 77.2% of respondents suffered from menopausal symptoms.19 This discrepancy might be partly due to regional differences and using different measurement instruments for menopausal symptoms.
Our findings are also in line with the results of previous Chinese studies in women from Guangdong, Zhejiang, and Hong Kong and other Asian studies from Japan, Korea, and Singapore indicating that the most frequently reported menopausal symptoms in midlife women focused on somatic symptoms including insomnia and fatigue.18-23 The most common symptom reported in this study was insomnia with the prevalence of 44.7% that was higher in a cross-sectional study based on northern Chinese populations (32.1%) and lower than a survey in Beijing middle-aged nurses (58.9%).24,25 The second most prevalent symptom was fatigue (40.4%), and the rate of fatigue reported in our study was slightly higher than a survey conducted in Guangdong (37.2%) and lower than that reported based on Zhejiang populations (46.1%).18,19 The third most predominant symptom was mood swings with a rate of 37.2% that was similar to that reported in Japanese populations (38.8%).26
In contrast to findings from most Asian studies, the most predominant menopausal symptom reported by Western women was vasomotor symptoms, such as hot flashes and night sweats.10 The Study of Women's Health Across the Nation (SWAN) based on multiethnic US communities indicated that 60% to 80% of women experienced vasomotor symptoms during menopausal transition with the highest rates reported in African Americans,27 whereas the prevalence of hot flashes reported by women during menopausal transition in our study was only 36.1%. This disparity between Asian and Western women might be partly interpreted by ethnic differences, and the difference in health behaviors such as smoking, dietary factors, and physical activity, and the prevalence of obesity and other social and demographic factors.27
In addition, we also found that several factors including menopausal status, residence, chronic diseases, and symptoms of anxiety and depression were associated with menopausal symptoms. In concordance with our results demonstrating that women in menopausal transition or postmenopause were more likely to suffer from menopausal symptoms, a cross-sectional study including 2,201 Korean women aged 44 to 56 years suggested that menopausal status was associated with the risk of menopausal symptoms based on vasomotor, psychosocial, physical, and sexual symptoms related to menopause.20 The SWAN involving five ethnic groups also demonstrated that menopausal status was strongly related to vasomotor symptoms.11 Moreover, we observed that women in menopausal transition had the highest rate of menopausal symptoms (23.9%), followed by postmenopausal women (21.5%), and the rates of both were significantly higher than that of women in reproductive stage (9.3%), which also support the associations between menopausal status and symptoms.
Furthermore, we observed that women residing in rural areas had 18% higher risk of menopausal symptoms compared with those living in urban areas. In contrast, another cross-section study recruiting 1,054 midlife women in southeast China indicated that women living in rural or suburban areas were less likely to experience menopausal symptoms than those living in urban areas.18 The relationship between place of residence and menopausal symptoms remains controversial, and might be affected by several factors, such as social and personal attitude toward aging and menopause, knowledge of menopausal symptoms, and awareness of treatment for menopausal symptoms.28
The findings of the current study agree with the results of earlier studies reporting that nulliparity was associated with menopausal symptoms.29-32 Our study showed that nulliparous women were more likely to experience menopausal symptoms compared with those having one or two births, which was consistent with a recent cross-sectional study conducted in Northwest China indicating that women with nulliparity appeared to have higher risks of menopausal syndrome.29 Compared with women having one or two births, nulliparous women in our study were less likely to have regular physical activity, and reported lower levels of average monthly household income. However, our findings differ from results in SWAN, which found that nulliparous women had lower odds of menopausal symptoms.32 Inconsistent results might be partly due to disparity in menopausal status and socioeconomic factors of study participants.
The main strengths of this study include a relatively large sample size, and the assessment of menopausal symptoms by using a validated instrument, and adjustment for potential confounding factors comprehensively. There are several limitations to be noted. First, due to the cross-sectional study design, we are unable to determine the causality between menopausal symptoms and their risk factors such as chronic diseases and symptoms of anxiety and depression. Second, our data only consisted of Chinese Han population, which limited the generalizability of the results to middle-aged women of other ethnic groups. Finally, we lacked the data on hormones such as follicle-stimulating hormone, estrogen, and progesterone, so we cannot evaluate the influence of hormone levels on menopausal symptoms in middle-aged women.
CONCLUSIONS
In summary, our study indicated that women in menopausal transition or postmenopause were more likely to suffer from menopausal symptoms than those in the reproductive stage. We found that menopausal transition and postmenopause, residing in rural areas, the presence of chronic diseases, and symptoms of anxiety and depression were significant risk factors for menopausal symptoms in middle-aged Chinese women. Our findings emphasize the importance of paying more attentions to the management of menopausal symptoms among women who were in menopausal transition or postmenopause, and resided in rural areas, and had chronic diseases, and experienced symptoms of anxiety and depression. Further studies are needed to confirm our findings and to explore the potential mechanisms underlying the relationship between menopausal symptoms and their contributing factors in middle-aged women.
Supplementary Material
Acknowledgments
We thank all participants and investigators who made it possible to complete this research project.
Footnotes
X.Z. and G.Z. are co-corresponding authors.
Funding/support: None reported.
Financial disclosures/conflicts of interest: None reported.
X.W. designed the study, performed the statistical analyses, and drafted manuscript. L.W. and J.D. collected the data. X.Z. and G.Z. designed the study and interpreted the data.
The study protocol was approved by the Ethical Review Committee of the Chinese Center for Disease Control and Prevention. Participants provided informed consent.
Supplemental digital content is available for this article.
REFERENCES
- 1.Nelson HD. Menopause. Lancet 2008; 371:760–770. [DOI] [PubMed] [Google Scholar]
- 2.Schoenaker DA, Jackson CA, Rowlands JV, Mishra GD. Socioeconomic position, lifestyle factors and age at natural menopause: a systematic review and meta-analyses of studies across six continents. Int J Epidemiol 2014; 43:1542–1562. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Al-Safi ZA, Santoro N. Menopausal hormone therapy and menopausal symptoms. Fertil Steril 2014; 101:905–915. [DOI] [PubMed] [Google Scholar]
- 4.Monteleone P, Mascagni G, Giannini A, Genazzani AR, Simoncini T. Symptoms of menopause—global prevalence, physiology and implications. Nat Rev Endocrinol 2018; 14:199–215. [DOI] [PubMed] [Google Scholar]
- 5.Polo-Kantola P. Sleep problems in midlife and beyond. Maturitas 2011; 68:224–232. [DOI] [PubMed] [Google Scholar]
- 6.Muka T, Oliver-Williams C, Kunutsor S, et al. Association of age at onset of menopause and time since onset of menopause with cardiovascular outcomes, intermediate vascular traits, and all-cause mortality: a systematic review and meta-analysis. JAMA Cardiol 2016; 1:767–776. [DOI] [PubMed] [Google Scholar]
- 7.Calleja-Agius J, Brincat M. The effect of menopause on the skin and other connective tissues. Gynecol Endocrinol 2012; 28:273–277. [DOI] [PubMed] [Google Scholar]
- 8.Greenblum CA, Rowe MA, Neff DF, Greenblum JS. Midlife women: symptoms associated with menopausal transition and early postmenopause and quality of life. Menopause 2013; 20:22–27. [DOI] [PubMed] [Google Scholar]
- 9.Islam MR, Gartoulla P, Bell RJ, Fradkin P, Davis SR. Prevalence of menopausal symptoms in Asian midlife women: a systematic review. Climacteric 2015; 18:157–176. [DOI] [PubMed] [Google Scholar]
- 10.Baber RJ. East is east and West is west: perspectives on the menopause in Asia and The West. Climacteric 2014; 17:23–28. [DOI] [PubMed] [Google Scholar]
- 11.Gold EB, Colvin A, Avis N, et al. Longitudinal analysis of the association between vasomotor symptoms and race/ethnicity across the menopausal transition: study of women's health across the nation. Am J Public Health 2006; 96:1226–1235. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Thurston RC, Sowers MR, Sutton-Tyrrell K, et al. Abdominal adiposity and hot flashes among midlife women. Menopause 2008; 15:429–434. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Deng X, Gaffney M, Grosse SD. Early Hearing Detection and Intervention in the United States: achievements and challenges in the 21(st) century. China CDC Wkly 2020; 2:378–382. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Harlow SD, Gass M, Hall JE, et al. Executive summary of the Stages of Reproductive Aging Workshop +10: addressing the unfinished agenda of staging reproductive aging. Climacteric 2012; 15:105–114. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Tao M, Shao H, Li C, Teng Y. Correlation between the modified Kupperman Index and the Menopause Rating Scale in Chinese women. Patient Prefer Adherence 2013; 7:223–229. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Cao Z. Chinese Obstetrics and Gynecology. Beijing, People's Republic of China: People's Medical Publishing House; 2014. [Google Scholar]
- 17.Wang Y, Mi J, Shan XY, Wang QJ, Ge KY. Is China facing an obesity epidemic and the consequences? The trends in obesity and chronic disease in China. Int J Obes (Lond) 2007; 31:177–188. [DOI] [PubMed] [Google Scholar]
- 18.Lan Y, Huang Y, Song Y, et al. Prevalence, severity, and associated factors of menopausal symptoms in middle-aged Chinese women: a community-based cross-sectional study in southeast China. Menopause 2017; 24:1200–1207. [DOI] [PubMed] [Google Scholar]
- 19.Yang D, Haines CJ, Pan P, et al. Menopausal symptoms in mid-life women in southern China. Climacteric 2008; 11:329–336. [DOI] [PubMed] [Google Scholar]
- 20.Yim G, Ahn Y, Chang Y, et al. Prevalence and severity of menopause symptoms and associated factors across menopause status in Korean women. Menopause 2015; 22:1108–1116. [DOI] [PubMed] [Google Scholar]
- 21.Chim H, Tan BH, Ang CC, Chew EM, Chong YS, Saw SM. The prevalence of menopausal symptoms in a community in Singapore. Maturitas 2002; 41:275–282. [DOI] [PubMed] [Google Scholar]
- 22.Lam PM, Leung TN, Haines C, Chung TK. Climacteric symptoms and knowledge about hormone replacement therapy among Hong Kong Chinese women aged 40-60 years. Maturitas 2003; 45:99–107. [DOI] [PubMed] [Google Scholar]
- 23.Kasuga M, Makita K, Ishitani K, et al. Relation between climacteric symptoms and ovarian hypofunction in middle-aged and older Japanese women. Menopause 2004; 11:631–638. [DOI] [PubMed] [Google Scholar]
- 24.Shea JL. Chinese women's symptoms: relation to menopause, age and related attitudes. Climacteric 2006; 9:30–39. [DOI] [PubMed] [Google Scholar]
- 25.Liu M, Wang Y, Li X, et al. A health survey of Beijing middle-aged registered nurses during menopause. Maturitas 2013; 74:84–88. [DOI] [PubMed] [Google Scholar]
- 26.Ishizuka B, Kudo Y, Tango T. Cross-sectional community survey of menopause symptoms among Japanese women. Maturitas 2008; 61:260–267. [DOI] [PubMed] [Google Scholar]
- 27.Thurston RC, Joffe H. Vasomotor symptoms and menopause: findings from the Study of Women's Health across the Nation. Obstet Gynecol Clin North Am 2011; 38:489–501. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Jin F, Tao M, Teng Y, Shao H, Li C, Mills E. Knowledge and attitude towards menopause and hormone replacement therapy in Chinese women. Gynecol Obstet Invest 2015; 79:40–45. [DOI] [PubMed] [Google Scholar]
- 29.Sun X, Zhang R, Wang L, et al. Association between parity and the age at menopause and menopausal syndrome in Northwest China. Asia Pac J Public Health 2021; 33:60–66. [DOI] [PubMed] [Google Scholar]
- 30.Li L, Wu J, Pu D, et al. Factors associated with the age of natural menopause and menopausal symptoms in Chinese women. Maturitas 2012; 73:354–360. [DOI] [PubMed] [Google Scholar]
- 31.Chedraui P, Hidalgo L, Chavez D, Morocho N, Alvarado M, Huc A. Menopausal symptoms and associated risk factors among postmenopausal women screened for the metabolic syndrome. Arch Gynecol Obstet 2007; 275:161–168. [DOI] [PubMed] [Google Scholar]
- 32.Cortés YI, Conant R, Catov JM, et al. Impact of nulliparity, hypertensive disorders of pregnancy, and gestational diabetes on vasomotor symptoms in midlife women. Menopause 2020; 27:1363–1370. [DOI] [PMC free article] [PubMed] [Google Scholar]
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