Journal of Psychosomatic Research 76 (2014) 237–241
Contents lists available at ScienceDirect
Journal of Psychosomatic Research
Sleep disturbance and correlates in menopausal women in Shanghai Dongmei Sun, Hongfang Shao, Changbin Li, Minfang Tao ⁎ Department of Obstetrics and Gynecology, The Sixth Affiliated People's Hospital of Shanghai Jiao Tong University, Shanghai, China
a r t i c l e
i n f o
Article history: Received 24 September 2013 Received in revised form 1 December 2013 Accepted 2 December 2013 Keywords: Menopause Sleep disturbance Regression analysis
a b s t r a c t Objective: The aim of this study was to investigate the sleep disturbance and its correlates in Chinese middle-aged women. Methods: A total of 2046 Chinese women 40–60 years of age were recruited in this cross-sectional descriptive study. The subjects were surveyed using the Pittsburgh Sleep Quality Index (PSQI), the modified Kupperman Index (KI), and a general questionnaire to obtain sociodemographic data. Data were analyzed using SPSS 20.0 software. Results: In this study, the mean (standard deviation) age of the participants was 51.69 (6.54) years and the mean PSQI score was 6.88 (3.20). The prevalence of sleep disturbance was 33.2% (a PSQI global score ≥8). The prevalence of sleep disturbance was higher in women with a menopausal status (from 34.8% in premenopausal women to 40.9% in postmenopausal women, P b .001) and in women with an increased age (from 21.7% in women 40–44 years of age to 41.8% in women 55–60 years of age, P b .001). Vasomotor symptoms (classical menopausal symptoms, VMS) were associated with sleep disturbance. An increase in the severity of menopausal symptoms (higher total KI scores) was observed in women who experienced sleep disturbance. A logistic regression analysis revealed that menopausal status, vasomotor symptoms, modified KI scores, a history of disease, and older age (≥50 years) were significant risk factors for sleep disturbance. Conclusions: Sleep disturbance was highly prevalent in this large sample of middle-aged Chinese women. Therefore, clinicians should pay more attention to sleep problems in middle-aged Chinese women and measures should be taken to improve the quality of sleep in these women. © 2013 Elsevier Inc. All rights reserved.
Introduction Menopause occurs because of the depletion of ovarian follicles, which indicates the end of fertility. The gradual or sudden cessation of estradiol and progesterone production by the ovaries impacts many tissues, from brain to skin [1]. Women may experience somatic, psychological, and urogenital symptoms. Sleep disturbance is one of the most common symptoms in menopause and mainly includes trouble falling asleep, waking up several times during the night, and waking up earlier than planned and unable to fall asleep again [2]. Women who experience a prolonged period of poor sleep are more susceptible to disease, such as depression, cardiovascular disease, and obesity [3–5]. Therefore, it is important for clinicians to consider sleep disturbance in menopausal women. Epidemiological studies have found that perimenopausal and postmenopausal women reported significantly more subjective sleep disturbance than premenopausal women [6,7]. The increase in sleep disturbance during the menopausal transition is multi-factorial [8]. Several studies have suggested that age, menopause, menopause-
related symptoms, mood problems, depression, and chronic illness are factors associated with sleep disturbance [9–11]. However, Kravitz et al. found that a poor health perception and nervousness were the most significant correlates of sleep disturbance during the menopausal transition [12]. Few epidemiological studies have assessed subjective sleep disturbance in Chinese women during the menopausal transition. Kravitz et al. found that Asian women reported less sleep difficulty than Caucasian women [12]. Therefore, this study aimed to investigate sleep disturbance and its correlates in Chinese middle-aged women. Studies in other countries have found that sleep disturbance is closely associated with vasomotor symptoms (classical menopausal symptoms, VMS) [12,13]. We hypothesized that vasomotor symptoms would be associated with sleep disturbance in Chinese women. The results of this evaluation of sleep disturbance in Chinese middle-aged women will be discussed. Methods Subjects and study design
⁎ Corresponding author at: Department of Obstetrics and Gynecology, The Sixth Affiliated People's Hospital of Shanghai Jiaotong University, 600 Yi Shan Road Shanghai, 200233, China. Tel.: +86 18930177770. E-mail address: [email protected] (M. Tao). 0022-3999/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jpsychores.2013.12.002
From June 2012 to March 2013, a cross-sectional study was performed at the physical examination center, of the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University, in Shanghai, China.
238
D. Sun et al. / Journal of Psychosomatic Research 76 (2014) 237–241
the mean (standard deviations, SD) and the percentage (95% confidence intervals, CI). The comparison of the sociodemographic data, the prevalence of sleep disturbance, the sleep variables, and the menopausal symptoms between the pre-, peri- and postmenopausal women was analyzed using one-way analysis of variance (ANOVA) for the continuous variables and chi-squared test for the categorical variables. Post-hoc analyses were performed when ANOVA revealed significant differences between the women according to menopausal status. A multiple logistic regression analysis was performed for the simultaneous assessment of the different variables that influenced sleep disturbance. For all of the calculations, a P value b .05 was considered to be statistically significant.
Women who visited the physical examination center for a routine check-up were recruited. The inclusion criteria of this study were as follows: (1) 40–60 years of age, (2) no oral contraceptive, or hormone therapy, (3) no history of psychiatric illness, and (4) no history of a surgical operation in the last 6 months. A face-to-face survey was conducted by trained personnel to identify women who met the inclusion criteria. Eligible subjects were asked to fill out the Chinese versions of the Pittsburgh Sleep Quality Index (PSQI), the modified Kupperman Index (KI), and a questionnaire to obtain basic personal data. The women were informed about the purpose and content of the research and were asked to give written informed consent before participating in the study. The research protocol was approved by the ethics review board of the hospital.
Results
Instruments
Participants
General questionnaire A questionnaire was used to obtain personal data, including age, education, occupation, family income, menopausal and marital status, parity, body mass index (BMI), age at menarche and menopause, habits (smoking and drinking), and history of chronic disease. Menopausal status was assessed using self-reported menstrual history. Premenopause was defined as the occurrence of a regular menstrual period within the previous 3 months. Perimenopause was defined as the presence of amenorrhea for at least 3 months but less than 12 months or the onset of irregular menstrual periods in the previous 3 months. Postmenopause was defined as the presence of amenorrhea for at least 12 months or a history of bilateral oophorectomy that was performed 6 or more months before the study [6]. Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared. The BMI values were categorized as low (b18.50 kg/m2), normal (18.50–24.99 kg/m2), overweight (25.00–29.99 kg/m2), or obese (≥30.00 kg/m2) [14]. Hypertension was defined as a blood pressure ≥140/90 mm Hg or the use of antihypertensive drugs. Diabetes mellitus was identified by the use of hypoglycemic drugs. Validated tools The PSQI is a self-rating instrument that measures subjective sleep quality during the previous month [15]. The PSQI includes 19 items that are used to generate scores based on the following 7 components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, use of sleeping medications, and daytime dysfunction. Each item can be scored from 0 to 3. The 7 component scores are summed to produce a global PSQI score, which ranges from 0 to 21. A PSQI global score of 8 or higher was defined as poor sleep quality, and higher scores indicated poorer sleep quality. The modified KI is widely used to evaluate menopause symptoms in the present, which consists of 13 items [16]. The 13 items included hot flushes/night sweats (as vasomotor symptoms, VMS), paresthesia, dizziness, arthralgia/myalgia, headache, palpitations and formication (categorized as somatic symptoms); insomnia/sleep disturbance, depression, irritability, and fatigue (categorized as psychological symptoms); and urinary infection and sexual complaints categorized as urogenital symptoms. The scores range from 0 to 3 (none, mild, moderate and severe). The weighted score for hot flushes and sweating is 4. Paresthesia, insomnia, irritability, sexual complaints, and urinary infection receive 2 points each. The other symptoms receive 1 point each. The total KI score ranges from 0 to 63, and this score is calculated as the sum of all of the scores for each item. Score ranges of 0–6, 7–15, 16–30, and N30 were used to rate the degree of severity as none, mild, moderate, and severe, respectively. Statistical analysis The data analysis was performed using SPSS 20.0 for Windows. Descriptive statistics were used to analyze the demographic data and the independent variables. The descriptive results were expressed as
During the study period, a total of 2068 women agreed to participate. Overall, 1.1% of the women provided incomplete data; therefore, 2046 subjects were available for the final analysis. The demographic characteristics of the subjects are provided in Table 1. The mean age of the subjects was 51.69 (6.54) years, and the ages ranged from 40 to 60 years. The mean age at natural menopause was 50.57 (3.34) years, and the ages ranged from 35 to 60 years in this study.
Prevalence of sleep disturbance In this study, the mean PSQI score was 6.88 (3.20). Overall, 33.2% of the subjects reported sleep disturbance. The prevalence of sleep disturbance was higher in women with an increased age and in women with a menopausal status. Indeed, the prevalence of sleep disturbance significantly increased from 21.7% in women 40–44 years of age to 41.8% in women 55–60 years of age, and the difference was statistically significant (x2 = 62.36, P b .01). Similarly, only 24.8% of the premenopausal women reported sleep disturbance, whereas 34.8% of the perimenopausal women and 40.9% of the postmenopausal women reported sleep disturbance (x2 = 55.70, P b .01). A similar increasing trend was observed for parity,
Table 1 General demographic data of participants Variables Age, years 40–44 45–49 50–54 55–60 Educational years b10 (primary school) 10–15 (middle school) N15 (university) Marital status Married Divorced/widowed Single Parity 0 1–2 ≥3 Income (RMB/per month) b3000 3000–5000 N5000 Body mass index, kg/m2 Low Normal Overweight Obese Missing Current smoking Current drinking History of disease Obesity Hypertension Diabetes mellitus Menopausal status Premenopause Perimenopause Postmenopause
n (%) 392 (19.2) 413 (20.2) 348 (17.0) 893 (43.6) 183 (8.9) 863 (42.2) 1000 (48.9) 2011 (98.3) 31 (1.5) 4 (0.2) 57 (2.8) 1898 (92.8) 91 (4.4) 741 (36.2) 844 (41.3) 461 (22.5) 65 (3.2) 1501 (73.4) 435 (21.3) 42 (2.1) 3 (0.1) 8 (0.39) 24 (1.17) 42 (2.1) 603 (29.47) 86 (4.20) 930 (45.5) 141 (6.9) 975 (47.7)
D. Sun et al. / Journal of Psychosomatic Research 76 (2014) 237–241 chronic disease, and the modified KI score, whereas a decreasing trend was observed for years of education and income as shown in Table 2. Table 3 presents the PSQI scores (total and items) according to menopausal status. Compared with the premenopausal women, the mean global PSQI scores were significantly higher in the perimenopausal and postmenopausal women. The differences in the PSQI subscales were significant between the pre-, peri-, and postmenopausal women (P b .01). The scores for each PSQI item indicated an increasing trend from the premenopausal to postmenopausal women, excluding sleep duration. For habitual sleep efficiency, the scores increased from 0.91 ± 0.90 in the premenopausal women to 1.33 ± 1.03 in the postmenopausal women. Table 4 presents the relationship between the severity of VMS (the scores for item 1 in the modified KI) and sleep disturbance. The PSQI scores increased with the severity of VMS. The scores were approximately 2 times higher in women who presented with severe VMS. The same trend was observed for the prevalence of sleep disturbance. Table 5 presents the relationship between sleep disturbance and menopausal symptoms. The modified KI scores (the total scores and the subscales) were higher in women who reported sleep disturbance. Indeed, the total KI scores were observed to be significantly higher in women who reported sleep disturbance compared with the women who did not report sleep disturbance (13.39 ± 6.27 vs. 8.23 ± 5.09, P b .01). The same trend was observed for somatic symptoms, psychological symptoms, and urogenital symptoms (5.39 ± 4.13 vs. 3.32 ± 3.17, 4.33 ± 2.05 vs. 2.39 ± 1.58, 3.67 ± 2.93 vs. 2.53 ± 2.78, respectively, P b .01).
Risk factors for sleep disturbance The odds ratios for the association between sleep disturbance and the predictors of sleep disturbance are depicted in Table 6. The logistic regression analysis revealed that menopausal status, VMS, modified KI scores, a history of disease, and older age (≥50 years) were significant risk factors for sleep disturbance. The risk of sleep disturbance was 1.59 times higher in the perimenopausal women and 1.23 times higher in the postmenopausal women than in premenopausal women. The women who were suffering from menopausal symptoms (a KI score N 6 points) had a 4.82 times higher risk than those without menopausal symptoms. In addition, a higher educational level (N15 years) and a higher income (N5000 RMB/per month) were independent risk factors that were associated with better sleep quality (0.39; 95% CI, 0.28–0.54. and 0.64; 95% CI, 0.45–0.92, respectively).
Table 2 Analysis of general characteristics associated with sleep disturbance Variables Age, years 40–44 45–49 50–54 55–60 Educational years b10 (primary school) 10–15 (middle school) N15 (university) Parity 0 1–2 ≥3 Income (RMB/per month) b3000 3000–5000 N5000 Body mass index, kg/m2 Low Normal Overweight Obese Chronic disease Yes No Modified KI score ≤6 7–15 16–30 N30 Menopausal status Premenopause Perimenopause Postmenopause
PSQI b 8 N (%)
PSQI ≥ 8 N (%)
307 (78.3) 305 (73.8) 235 (67.5) 520 (58.2)
85 (21.7) 108 (26.2) 113 (32.5) 373 (41.8)
80 (43.7) 549 (63.6) 738 (73.8)
103 (56.3) 314 (36.4) 262 (26.2)
39 (68.4) 1285 (67.7) 43 (47.3)
18 (31.6) 613 (32.3) 48 (52.7)
435 (58.7) 563 (66.7) 369 (80.0)
306 (41.3) 281 (33.3) 92 (20.0)
39 (60.0) 1008 (67.2) 291 (66.9) 27 (64.3)
26 (40.0) 493 (32.8) 144 (33.1) 15 (35.7)
420 (61.9) 951 (69.6)
259 (38.1) 416 (30.4)
593 (87.5) 654 (64.0) 119 (35.3) 1 (11.1)
85 (12.5) 368 (36.0) 218 (64.7) 8 (88.9)
699 (75.2) 92 (65.2) 576 (59.1)
231 (24.8) 49 (34.8) 399 (40.9)
X2
P
62.36
b.001
70.03
b.001
16.45
b.001
58.37
b.001
1.56
.67
12.207
b.001
297.47
55.70
Subjective sleep disturbance and menopausal symptoms.
b.001
b.001
239
Table 3 Scores for PSQI (total and items) according to menopausal status PSQI items
Premenopause
Perimenopause
Postmenopause
P value⁎
Subjective sleep quality Sleep latency Sleep duration Habitual sleep efficiency Sleep disturbance Need medication to sleep Daytime dysfunction Total score
1.10 ± 0.48
1.17 ± 0.51
1.22 ± 0.57
b.001
0.67 ± 0.92 1.21 ± 0.83 0.91 ± 0.90
0.96 ± 1.12 1.48 ± 0.72 1.14 ± 0.99
1.06 ± 1.11 1.38 ± 0.93 1.33 ± 1.03
b.001 b.001 b.001
1.02 ± 0.33 0.03 ± 0.28
1.07 ± 0.26 0.04 ± 0.29
1.12 ± 0.35 0.09 ± 0.43
b.001 .002
1.21 ± 0.47 6.15 ± 2.79
1.21 ± 0.48 7.09 ± 3.06
1.34 ± 0.55 7.55 ± 3.43
b.001 b.001
⁎ P value as determined with the ANOVA.
Discussion In this study, we aimed to determine the prevalence and correlates of sleep disturbance in menopausal women in China. Currently, most researchers in other countries measure sleep quality using the PSQI scales that were created by Dr. Buysse at the University of Pittsburgh. A revised version that has a higher degree of reliability and validity has often been adopted by researchers in China [15]. In this study, 33.2% of the subjects reported sleep disturbance. This finding differs slightly from the findings in a study that was conducted in the United States (US) with a multiethnic, community-based sample, which found that 38% of women 40–55 years of age reported sleep difficulty during the previous 2 weeks; however, the Asian women in the study were less likely to report sleep difficulty [12]. A study in Japan found that approximately 51% of peri- and postmenopausal women in a menopause clinic sample suffered from sleep disturbance [3]. A study in Turkey found that 54% of women 45–59 years of age in a population-based sample reported sleep disturbance [17]. Additionally, a study in Hong Kong found that 26% of women 45–55 years of age in a community-based sample were poor sleepers [7]. Despite the differences in the methodology, races, regions, and samples in the studies, the findings of this study suggest that sleep disturbance is common in menopausal women. We found that peri- and postmenopausal women reported significantly more sleep disturbance than premenopausal women. The majority of studies have obtained similar findings [7,10,12,18]. However, Owens et al. found no association between sleep disturbance and menopausal status [19]. Their findings differ from the results of this study most likely because they surveyed women 42–50 years of age who were mostly premenopausal and of a different ethnic origin. Additionally, we found that the prevalence of sleep disturbance significantly increased with age and the magnitude of this aggrandizement was not moderate. Our findings are in agreement with previous studies [20,21]. In addition, we found that the prevalence of sleep disturbance increased with parity, chronic disease, and modified KI scores but decreased with years of education and income. Women with greater parity may experience more stress; therefore, their sleep quality may be disturbed. Sleep quality was poorer in overweight and obese women than in women with a healthy weight; however, this difference was not statistically significant. The findings of this study are inconsistent with those of the Prather et al. study, which Table 4 Relationship between severity of VMS and sleep disturbance VMS score (KI item 1)
Women number
PSQI Total scores
Sleep disturbance (%)
OR (95% CI)
0 1 2 3 P value⁎
1449 473 108 16
6.46 ± 2.93 7.64 ± 3.43 8.69 ± 3.91 10.63 ± 3.92 b.0011
405 (28.0) 202 (42.7) 60 (55.6) 12 (75.0) b.0012
1.0 1.92 (1.55–2.38) 3.22 (2.17–4.79) 7.73 (2.48–24.12) b.0012
⁎ P value as determined with the ANOVA1 and Chi-square test2; VMS score: 0: none, 1: mild, 2: moderate, and 3:severe.
240
D. Sun et al. / Journal of Psychosomatic Research 76 (2014) 237–241
OR
95% CI
392 413 348 893
1.0 1.28 1.70** 2.61**
0.92–1.77 1.22–2.37 1.97–3.43
Educational years b10 (primary school) 10–15 (middle school) N15 (university)
1000 183 863
1.0 0.51** 0.39**
0.37–0.71 0.28–0.54
Marital status Married Divorced/widowed Single
2011 31 4
1.0 0.96 0.35
0.45–2.04 0.16–1.02
741 844 461
1.0 0.95 0.64*
0.74–1.23 0.45–0.92
Body mass index, kg/m2 Low Normal Overweight Obese
65 1501 435 42
1.0 0.73 0.74 0.79
0.44–1.22 0.43–1.27 0.52–1.47
Current smoking No Yes
2038 8
1.0 1.87
0.39–8.87
Current drinking No Yes
2022 24
1.0 1.61
0.65–4.01
History of disease No Yes
1367 679
1.0 1.35*
1.08–1.68
increased in parallel with the intensity of vasomotor symptoms. The relationship between vasomotor symptoms and sleep disturbance has been reported in other studies [20,23]. Laboratory research has demonstrated that vasomotor symptoms were associated with cortical arousals and the disruption of sleep architecture, such as reduced sleep efficiency, increased nocturnal awakenings and changes in sleep stages [24,25]. However, the precise mechanisms through which hot flushes influence sleep disturbance are not well known. Sleep disturbance is often caused by hot flushes and sweating at night, which are associated with hormonal changes. Estrogen tends to decrease sleep latency, decrease the number of awakenings after sleep occurs, and increase total sleep time [26]. In addition, temperature regulation in the body is influenced by estrogen, and low levels are associated with increases in both peripheral and central temperatures, thereby resulting in hot flushes that are characteristic of menopause [27]. In addition to menopausal status and VMS, we found that general subject characteristics, such as older age and a history of disease, were independent risk factors for sleep disturbance according to the logistic regression analysis. Our findings are consistent with previous studies, which older age and a history of disease have been found as risk factors for sleep disturbance [12,18]. Older age has been associated with a 2-fold increase in the risk of sleep disturbance. A study in Korea demonstrated that sleep disturbance most frequently occurred in the elderly [18]. Age-related hormonal changes that occur with sleep architecture and sleep perception may contribute to the development of sleep disturbance. Women with chronic diseases reported more sleep disturbance than women without chronic diseases. Finally, this study confirmed that higher education and income levels exert a protective role against sleep disturbance, which has been reported in a study of Hispanic women [18,20]. Our study had several limitations. First, this study used a crosssectional design; therefore, the causality of the association could not be addressed. An additional longitudinal study is needed to determine the influence of menopause on sleep disturbance. Second, this study was based on only subjective assessments (e.g., the PSQI) of sleep quality. Subjective assessments may not always correlate with objective assessments (polysomnography) [28]. Nevertheless, objective assessments were unsuitable for this study due to their high cost and the high sample size of this study. Third, the survey instrument did not include an anxiety and depression rating scale. Therefore, we could not determine the relationship between sleep disturbance and anxiety and depression. However, previous studies have found that women with anxiety and depression symptoms reported more sleep disturbance [20]. Finally, we included both age and menopausal status in the analyses; however, there may have been overlap between the information that was obtained using the two variables and the effects of age and menopause are difficult to distinguish. In conclusion, sleep disturbance was highly prevalent in this large sample of middle-aged Chinese women. Menopausal status, VMS, menopausal symptom severity, a history of disease, and older age were important risk factors for sleep disturbance. Higher education and income levels were associated with better sleep quality. However, additional comprehensive research is needed to determine the factors that influence sleep disturbance. Finally, measures should be taken to improve the quality of life of middle-aged women.
Modified KI score Normal (≤6) Abnormal (N6)
678 1368
1.0 4.82**
3.74–6.22
Contributors
VMS No Yes
1449 597
1.0 1.25**
1.21–1.29
930 141 975
1.0 1.59** 1.23**
1.23–2.08 1.01–1.84
Table 5 Relationship between scores for modified KI (total and subscales) and sleep disturbance Sleep disturbance
Women number
Total KI score
Yes No P value⁎
679 1367
13.39 ± 6.27 8.23 ± 5.09 b.001
Modified KI subscales Somatic
Psychological
Urogenital
5.39 ± 4.13 3.32 ± 3.17 b.001
4.33 ± 2.05 2.39 ± 1.58 b.001
3.67 ± 2.93 2.53 ± 2.78 b.001
⁎ P value as determined with the Independent-Samples T Test.
found an association between sleep disturbance and being overweight or obese [5]. In this study, women with higher global PSQI scores had higher total and subscale KI scores (somatic, psychological, and urogenital); therefore, women with more severe symptoms experienced a worse quality of sleep. The findings in this study are consistent with those in a study in Colombia [22]. An interesting finding from this study was that vasomotor symptoms (hot flushes and sweating) were significantly associated with sleep disturbance. In addition, the prevalence of sleep disturbance
Table 6 Risk factors related to sleep disturbance Variables Age, years 40–44 45–49 50–54 55–60
Income (RMB/per month) b3000 3000–5000 N5000
Menopausal status Premenopause Perimenopause Postmenopause
N.
*P b .05,**P b .01, P value as determined with the logistic regression analysis.
Dongmei Sun and Minfang Tao assisted with the conception and design of the study. Dongmei Sun performed the data collection and the statistical analysis and drafted the manuscript. Hongfang Shao reviewed the manuscript. Changbin Li assisted with the data collection. Minfang Tao assisted with the interpretation of results and reviewed the manuscript. All of the authors have seen and approved the final version of the manuscript.
D. Sun et al. / Journal of Psychosomatic Research 76 (2014) 237–241
Conflict of interest statement The authors report no conflicts of interest in this work. Funding This research was supported by a grant from the Shanghai Science and Technology Commission (11411950103). Acknowledgments We would like to thank the women who participated in the study. References [1] 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;7:223–9. [2] Kravitz HM, Zhao X, Bromberger JT, Gold EB, Hall MH, Matthews KA, et al. Sleep disturbance during the menopausal transition in a multi-ethnic community sample of women. Sleep 2008;31:979–90. [3] Terauchi M, Obayashi S, Akiyoshi M, Kato K, Matsushima E, Kubota T. Insomnia in Japanese peri- and postmenopausal women. Climacteric 2010;13:479–86. [4] Sands-Lincoln M, Loucks EB, Lu B, Carskadon MA, Sharkey K, Stefanick ML, et al. Sleep duration, insomnia, and coronary heart disease among postmenopausal women in the Women's Health Initiative. J Womens Health (Larchmt) 2013;22:477–86. [5] Prather AA, Puterman E, Epel ES, Dhabhar FS. Poor sleep quality potentiates stressinduced cytokine reactivity in postmenopausal women with high visceral abdominal adiposity. Brain Behav Immun 2014;35:155–62. [6] Young T, Rabago D, Zgierska A, Austin D, Laurel F. Objective and subjective sleep quality in premenopausal, perimenopausal, and postmenopausal women in the Wisconsin Sleep Cohort Study. Sleep 2003;26:667–72. [7] Chung KF, Tang MK. Subjective sleep disturbance and its correlates in middle-aged Hong Kong Chinese women. Maturitas 2006;53:396–404. [8] Polo-Kantola P, Saaresranta T, Polo O. Aetiology and treatment of sleep disturbances during perimenopause and postmenopause. CNS Drugs 2001;15:445–52. [9] Cuadros JL, Fernandez-Alonso AM, Cuadros-Celorrio AM, Fernández-Luzón N, Guadix-Peinado MJ, Cid-Martín ND, et al. Perceived stress, insomnia and related factors in women around the menopause. Maturitas 2012;72:367–72.
241
[10] Cheng MH, Hsu CY, Wang SJ, Lee SJ, Wang PH, Fuh JL. The relationship of selfreported sleep disturbance, mood, and menopause in a community study. Menopause 2008;15:958–62. [11] Kawada T, Yosiaki S, Yasuo K, Suzuki S. Population study on the prevalence of insomnia and insomnia-related factors among Japanese women. Sleep Med 2003;4:563–7. [12] Kravitz HM, Ganz PA, Bromberger J, Powell LH, Sutton-Tyrrell K, Meyer PM. Sleep difficulty in women at midlife: a community survey of sleep and the menopausal transition. Menopause 2003;10:19–28. [13] Ohayon MM. Severe hot flashes are associated with chronic insomnia. Arch Intern Med 2006;166:1262–8. [14] Physical status: the use and interpretation of anthropometry. Report of a WHO Expert Committee. World Health Organ Tech Rep Ser 1995;854:1–452. [15] Liu X, Tang M, Hu L. Reliability and validity of the Pittsburgh sleep quality index. Chin J Psychiatry 1996;5:103–7. [16] Cao Z. Chinese obstetrics and gynecology. 2nd ed. Beijing: People's Republic of China: People's Medical Publishing House; 2005. [17] Timur S, Sahin NH. Effects of sleep disturbance on the quality of life of Turkish menopausal women: a population-based study. Maturitas 2009;64:177–81. [18] Shin C, Lee S, Lee T, Shin K, Yi H, Kimm K, et al. Prevalence of insomnia and its relationship to menopausal status in middle-aged Korean women. Psychiatry Clin Neurosci 2005;59:395–402. [19] Owens JF, Matthews KA. Sleep disturbance in healthy middle-aged women. Maturitas 1998;30:41–50. [20] Blumel JE, Cano A, Mezones-Holguin E, Baron G, Bencosme A, Benitez Z, et al. A multinational study of sleep disorders during female mid-life. Maturitas 2012;72:359–66. [21] Hajak G. Epidemiology of severe insomnia and its consequences in Germany. Eur Arch Psychiatry Clin Neurosci 2001;251:49–56. [22] Monterrosa-Castro A, Marrugo-Florez M, Romero-Perez I, Fernandez-Alonso AM, Chedraui P, Perez-Lopez FR. Assessment of sleep quality and correlates in a large cohort of Colombian women around menopause. Menopause 2013;20:464–9. [23] Arakane M, Castillo C, Rosero MF, Penafiel R, Perez-Lopez FR, Chedraui P. Factors relating to insomnia during the menopausal transition as evaluated by the Insomnia Severity Index. Maturitas 2011;69:157–61. [24] Polo-Kantola P. Sleep problems in midlife and beyond. Maturitas 2011;68:224–32. [25] Woodward S, Freedman RR. The thermoregulatory effects of menopausal hot flashes on sleep. Sleep 1994;17:497–501. [26] Miller EH. Women and insomnia. Clin Cornerstone 2004;6:S8–S18. [27] Eichling P. Evaluating and treating menopausal sleep problems. Menopause Manage 2002;11:8–17. [28] Vitiello MV, Larsen LH, Moe KE. Age-related sleep change: gender and estrogen effects on the subjective-objective sleep quality relationships of healthy, noncomplaining older men and women. J Psychosom Res 2004;56:503–10.
Contents lists available at ScienceDirect
Journal of Psychosomatic Research
Sleep disturbance and correlates in menopausal women in Shanghai Dongmei Sun, Hongfang Shao, Changbin Li, Minfang Tao ⁎ Department of Obstetrics and Gynecology, The Sixth Affiliated People's Hospital of Shanghai Jiao Tong University, Shanghai, China
a r t i c l e
i n f o
Article history: Received 24 September 2013 Received in revised form 1 December 2013 Accepted 2 December 2013 Keywords: Menopause Sleep disturbance Regression analysis
a b s t r a c t Objective: The aim of this study was to investigate the sleep disturbance and its correlates in Chinese middle-aged women. Methods: A total of 2046 Chinese women 40–60 years of age were recruited in this cross-sectional descriptive study. The subjects were surveyed using the Pittsburgh Sleep Quality Index (PSQI), the modified Kupperman Index (KI), and a general questionnaire to obtain sociodemographic data. Data were analyzed using SPSS 20.0 software. Results: In this study, the mean (standard deviation) age of the participants was 51.69 (6.54) years and the mean PSQI score was 6.88 (3.20). The prevalence of sleep disturbance was 33.2% (a PSQI global score ≥8). The prevalence of sleep disturbance was higher in women with a menopausal status (from 34.8% in premenopausal women to 40.9% in postmenopausal women, P b .001) and in women with an increased age (from 21.7% in women 40–44 years of age to 41.8% in women 55–60 years of age, P b .001). Vasomotor symptoms (classical menopausal symptoms, VMS) were associated with sleep disturbance. An increase in the severity of menopausal symptoms (higher total KI scores) was observed in women who experienced sleep disturbance. A logistic regression analysis revealed that menopausal status, vasomotor symptoms, modified KI scores, a history of disease, and older age (≥50 years) were significant risk factors for sleep disturbance. Conclusions: Sleep disturbance was highly prevalent in this large sample of middle-aged Chinese women. Therefore, clinicians should pay more attention to sleep problems in middle-aged Chinese women and measures should be taken to improve the quality of sleep in these women. © 2013 Elsevier Inc. All rights reserved.
Introduction Menopause occurs because of the depletion of ovarian follicles, which indicates the end of fertility. The gradual or sudden cessation of estradiol and progesterone production by the ovaries impacts many tissues, from brain to skin [1]. Women may experience somatic, psychological, and urogenital symptoms. Sleep disturbance is one of the most common symptoms in menopause and mainly includes trouble falling asleep, waking up several times during the night, and waking up earlier than planned and unable to fall asleep again [2]. Women who experience a prolonged period of poor sleep are more susceptible to disease, such as depression, cardiovascular disease, and obesity [3–5]. Therefore, it is important for clinicians to consider sleep disturbance in menopausal women. Epidemiological studies have found that perimenopausal and postmenopausal women reported significantly more subjective sleep disturbance than premenopausal women [6,7]. The increase in sleep disturbance during the menopausal transition is multi-factorial [8]. Several studies have suggested that age, menopause, menopause-
related symptoms, mood problems, depression, and chronic illness are factors associated with sleep disturbance [9–11]. However, Kravitz et al. found that a poor health perception and nervousness were the most significant correlates of sleep disturbance during the menopausal transition [12]. Few epidemiological studies have assessed subjective sleep disturbance in Chinese women during the menopausal transition. Kravitz et al. found that Asian women reported less sleep difficulty than Caucasian women [12]. Therefore, this study aimed to investigate sleep disturbance and its correlates in Chinese middle-aged women. Studies in other countries have found that sleep disturbance is closely associated with vasomotor symptoms (classical menopausal symptoms, VMS) [12,13]. We hypothesized that vasomotor symptoms would be associated with sleep disturbance in Chinese women. The results of this evaluation of sleep disturbance in Chinese middle-aged women will be discussed. Methods Subjects and study design
⁎ Corresponding author at: Department of Obstetrics and Gynecology, The Sixth Affiliated People's Hospital of Shanghai Jiaotong University, 600 Yi Shan Road Shanghai, 200233, China. Tel.: +86 18930177770. E-mail address: [email protected] (M. Tao). 0022-3999/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jpsychores.2013.12.002
From June 2012 to March 2013, a cross-sectional study was performed at the physical examination center, of the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University, in Shanghai, China.
238
D. Sun et al. / Journal of Psychosomatic Research 76 (2014) 237–241
the mean (standard deviations, SD) and the percentage (95% confidence intervals, CI). The comparison of the sociodemographic data, the prevalence of sleep disturbance, the sleep variables, and the menopausal symptoms between the pre-, peri- and postmenopausal women was analyzed using one-way analysis of variance (ANOVA) for the continuous variables and chi-squared test for the categorical variables. Post-hoc analyses were performed when ANOVA revealed significant differences between the women according to menopausal status. A multiple logistic regression analysis was performed for the simultaneous assessment of the different variables that influenced sleep disturbance. For all of the calculations, a P value b .05 was considered to be statistically significant.
Women who visited the physical examination center for a routine check-up were recruited. The inclusion criteria of this study were as follows: (1) 40–60 years of age, (2) no oral contraceptive, or hormone therapy, (3) no history of psychiatric illness, and (4) no history of a surgical operation in the last 6 months. A face-to-face survey was conducted by trained personnel to identify women who met the inclusion criteria. Eligible subjects were asked to fill out the Chinese versions of the Pittsburgh Sleep Quality Index (PSQI), the modified Kupperman Index (KI), and a questionnaire to obtain basic personal data. The women were informed about the purpose and content of the research and were asked to give written informed consent before participating in the study. The research protocol was approved by the ethics review board of the hospital.
Results
Instruments
Participants
General questionnaire A questionnaire was used to obtain personal data, including age, education, occupation, family income, menopausal and marital status, parity, body mass index (BMI), age at menarche and menopause, habits (smoking and drinking), and history of chronic disease. Menopausal status was assessed using self-reported menstrual history. Premenopause was defined as the occurrence of a regular menstrual period within the previous 3 months. Perimenopause was defined as the presence of amenorrhea for at least 3 months but less than 12 months or the onset of irregular menstrual periods in the previous 3 months. Postmenopause was defined as the presence of amenorrhea for at least 12 months or a history of bilateral oophorectomy that was performed 6 or more months before the study [6]. Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared. The BMI values were categorized as low (b18.50 kg/m2), normal (18.50–24.99 kg/m2), overweight (25.00–29.99 kg/m2), or obese (≥30.00 kg/m2) [14]. Hypertension was defined as a blood pressure ≥140/90 mm Hg or the use of antihypertensive drugs. Diabetes mellitus was identified by the use of hypoglycemic drugs. Validated tools The PSQI is a self-rating instrument that measures subjective sleep quality during the previous month [15]. The PSQI includes 19 items that are used to generate scores based on the following 7 components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, use of sleeping medications, and daytime dysfunction. Each item can be scored from 0 to 3. The 7 component scores are summed to produce a global PSQI score, which ranges from 0 to 21. A PSQI global score of 8 or higher was defined as poor sleep quality, and higher scores indicated poorer sleep quality. The modified KI is widely used to evaluate menopause symptoms in the present, which consists of 13 items [16]. The 13 items included hot flushes/night sweats (as vasomotor symptoms, VMS), paresthesia, dizziness, arthralgia/myalgia, headache, palpitations and formication (categorized as somatic symptoms); insomnia/sleep disturbance, depression, irritability, and fatigue (categorized as psychological symptoms); and urinary infection and sexual complaints categorized as urogenital symptoms. The scores range from 0 to 3 (none, mild, moderate and severe). The weighted score for hot flushes and sweating is 4. Paresthesia, insomnia, irritability, sexual complaints, and urinary infection receive 2 points each. The other symptoms receive 1 point each. The total KI score ranges from 0 to 63, and this score is calculated as the sum of all of the scores for each item. Score ranges of 0–6, 7–15, 16–30, and N30 were used to rate the degree of severity as none, mild, moderate, and severe, respectively. Statistical analysis The data analysis was performed using SPSS 20.0 for Windows. Descriptive statistics were used to analyze the demographic data and the independent variables. The descriptive results were expressed as
During the study period, a total of 2068 women agreed to participate. Overall, 1.1% of the women provided incomplete data; therefore, 2046 subjects were available for the final analysis. The demographic characteristics of the subjects are provided in Table 1. The mean age of the subjects was 51.69 (6.54) years, and the ages ranged from 40 to 60 years. The mean age at natural menopause was 50.57 (3.34) years, and the ages ranged from 35 to 60 years in this study.
Prevalence of sleep disturbance In this study, the mean PSQI score was 6.88 (3.20). Overall, 33.2% of the subjects reported sleep disturbance. The prevalence of sleep disturbance was higher in women with an increased age and in women with a menopausal status. Indeed, the prevalence of sleep disturbance significantly increased from 21.7% in women 40–44 years of age to 41.8% in women 55–60 years of age, and the difference was statistically significant (x2 = 62.36, P b .01). Similarly, only 24.8% of the premenopausal women reported sleep disturbance, whereas 34.8% of the perimenopausal women and 40.9% of the postmenopausal women reported sleep disturbance (x2 = 55.70, P b .01). A similar increasing trend was observed for parity,
Table 1 General demographic data of participants Variables Age, years 40–44 45–49 50–54 55–60 Educational years b10 (primary school) 10–15 (middle school) N15 (university) Marital status Married Divorced/widowed Single Parity 0 1–2 ≥3 Income (RMB/per month) b3000 3000–5000 N5000 Body mass index, kg/m2 Low Normal Overweight Obese Missing Current smoking Current drinking History of disease Obesity Hypertension Diabetes mellitus Menopausal status Premenopause Perimenopause Postmenopause
n (%) 392 (19.2) 413 (20.2) 348 (17.0) 893 (43.6) 183 (8.9) 863 (42.2) 1000 (48.9) 2011 (98.3) 31 (1.5) 4 (0.2) 57 (2.8) 1898 (92.8) 91 (4.4) 741 (36.2) 844 (41.3) 461 (22.5) 65 (3.2) 1501 (73.4) 435 (21.3) 42 (2.1) 3 (0.1) 8 (0.39) 24 (1.17) 42 (2.1) 603 (29.47) 86 (4.20) 930 (45.5) 141 (6.9) 975 (47.7)
D. Sun et al. / Journal of Psychosomatic Research 76 (2014) 237–241 chronic disease, and the modified KI score, whereas a decreasing trend was observed for years of education and income as shown in Table 2. Table 3 presents the PSQI scores (total and items) according to menopausal status. Compared with the premenopausal women, the mean global PSQI scores were significantly higher in the perimenopausal and postmenopausal women. The differences in the PSQI subscales were significant between the pre-, peri-, and postmenopausal women (P b .01). The scores for each PSQI item indicated an increasing trend from the premenopausal to postmenopausal women, excluding sleep duration. For habitual sleep efficiency, the scores increased from 0.91 ± 0.90 in the premenopausal women to 1.33 ± 1.03 in the postmenopausal women. Table 4 presents the relationship between the severity of VMS (the scores for item 1 in the modified KI) and sleep disturbance. The PSQI scores increased with the severity of VMS. The scores were approximately 2 times higher in women who presented with severe VMS. The same trend was observed for the prevalence of sleep disturbance. Table 5 presents the relationship between sleep disturbance and menopausal symptoms. The modified KI scores (the total scores and the subscales) were higher in women who reported sleep disturbance. Indeed, the total KI scores were observed to be significantly higher in women who reported sleep disturbance compared with the women who did not report sleep disturbance (13.39 ± 6.27 vs. 8.23 ± 5.09, P b .01). The same trend was observed for somatic symptoms, psychological symptoms, and urogenital symptoms (5.39 ± 4.13 vs. 3.32 ± 3.17, 4.33 ± 2.05 vs. 2.39 ± 1.58, 3.67 ± 2.93 vs. 2.53 ± 2.78, respectively, P b .01).
Risk factors for sleep disturbance The odds ratios for the association between sleep disturbance and the predictors of sleep disturbance are depicted in Table 6. The logistic regression analysis revealed that menopausal status, VMS, modified KI scores, a history of disease, and older age (≥50 years) were significant risk factors for sleep disturbance. The risk of sleep disturbance was 1.59 times higher in the perimenopausal women and 1.23 times higher in the postmenopausal women than in premenopausal women. The women who were suffering from menopausal symptoms (a KI score N 6 points) had a 4.82 times higher risk than those without menopausal symptoms. In addition, a higher educational level (N15 years) and a higher income (N5000 RMB/per month) were independent risk factors that were associated with better sleep quality (0.39; 95% CI, 0.28–0.54. and 0.64; 95% CI, 0.45–0.92, respectively).
Table 2 Analysis of general characteristics associated with sleep disturbance Variables Age, years 40–44 45–49 50–54 55–60 Educational years b10 (primary school) 10–15 (middle school) N15 (university) Parity 0 1–2 ≥3 Income (RMB/per month) b3000 3000–5000 N5000 Body mass index, kg/m2 Low Normal Overweight Obese Chronic disease Yes No Modified KI score ≤6 7–15 16–30 N30 Menopausal status Premenopause Perimenopause Postmenopause
PSQI b 8 N (%)
PSQI ≥ 8 N (%)
307 (78.3) 305 (73.8) 235 (67.5) 520 (58.2)
85 (21.7) 108 (26.2) 113 (32.5) 373 (41.8)
80 (43.7) 549 (63.6) 738 (73.8)
103 (56.3) 314 (36.4) 262 (26.2)
39 (68.4) 1285 (67.7) 43 (47.3)
18 (31.6) 613 (32.3) 48 (52.7)
435 (58.7) 563 (66.7) 369 (80.0)
306 (41.3) 281 (33.3) 92 (20.0)
39 (60.0) 1008 (67.2) 291 (66.9) 27 (64.3)
26 (40.0) 493 (32.8) 144 (33.1) 15 (35.7)
420 (61.9) 951 (69.6)
259 (38.1) 416 (30.4)
593 (87.5) 654 (64.0) 119 (35.3) 1 (11.1)
85 (12.5) 368 (36.0) 218 (64.7) 8 (88.9)
699 (75.2) 92 (65.2) 576 (59.1)
231 (24.8) 49 (34.8) 399 (40.9)
X2
P
62.36
b.001
70.03
b.001
16.45
b.001
58.37
b.001
1.56
.67
12.207
b.001
297.47
55.70
Subjective sleep disturbance and menopausal symptoms.
b.001
b.001
239
Table 3 Scores for PSQI (total and items) according to menopausal status PSQI items
Premenopause
Perimenopause
Postmenopause
P value⁎
Subjective sleep quality Sleep latency Sleep duration Habitual sleep efficiency Sleep disturbance Need medication to sleep Daytime dysfunction Total score
1.10 ± 0.48
1.17 ± 0.51
1.22 ± 0.57
b.001
0.67 ± 0.92 1.21 ± 0.83 0.91 ± 0.90
0.96 ± 1.12 1.48 ± 0.72 1.14 ± 0.99
1.06 ± 1.11 1.38 ± 0.93 1.33 ± 1.03
b.001 b.001 b.001
1.02 ± 0.33 0.03 ± 0.28
1.07 ± 0.26 0.04 ± 0.29
1.12 ± 0.35 0.09 ± 0.43
b.001 .002
1.21 ± 0.47 6.15 ± 2.79
1.21 ± 0.48 7.09 ± 3.06
1.34 ± 0.55 7.55 ± 3.43
b.001 b.001
⁎ P value as determined with the ANOVA.
Discussion In this study, we aimed to determine the prevalence and correlates of sleep disturbance in menopausal women in China. Currently, most researchers in other countries measure sleep quality using the PSQI scales that were created by Dr. Buysse at the University of Pittsburgh. A revised version that has a higher degree of reliability and validity has often been adopted by researchers in China [15]. In this study, 33.2% of the subjects reported sleep disturbance. This finding differs slightly from the findings in a study that was conducted in the United States (US) with a multiethnic, community-based sample, which found that 38% of women 40–55 years of age reported sleep difficulty during the previous 2 weeks; however, the Asian women in the study were less likely to report sleep difficulty [12]. A study in Japan found that approximately 51% of peri- and postmenopausal women in a menopause clinic sample suffered from sleep disturbance [3]. A study in Turkey found that 54% of women 45–59 years of age in a population-based sample reported sleep disturbance [17]. Additionally, a study in Hong Kong found that 26% of women 45–55 years of age in a community-based sample were poor sleepers [7]. Despite the differences in the methodology, races, regions, and samples in the studies, the findings of this study suggest that sleep disturbance is common in menopausal women. We found that peri- and postmenopausal women reported significantly more sleep disturbance than premenopausal women. The majority of studies have obtained similar findings [7,10,12,18]. However, Owens et al. found no association between sleep disturbance and menopausal status [19]. Their findings differ from the results of this study most likely because they surveyed women 42–50 years of age who were mostly premenopausal and of a different ethnic origin. Additionally, we found that the prevalence of sleep disturbance significantly increased with age and the magnitude of this aggrandizement was not moderate. Our findings are in agreement with previous studies [20,21]. In addition, we found that the prevalence of sleep disturbance increased with parity, chronic disease, and modified KI scores but decreased with years of education and income. Women with greater parity may experience more stress; therefore, their sleep quality may be disturbed. Sleep quality was poorer in overweight and obese women than in women with a healthy weight; however, this difference was not statistically significant. The findings of this study are inconsistent with those of the Prather et al. study, which Table 4 Relationship between severity of VMS and sleep disturbance VMS score (KI item 1)
Women number
PSQI Total scores
Sleep disturbance (%)
OR (95% CI)
0 1 2 3 P value⁎
1449 473 108 16
6.46 ± 2.93 7.64 ± 3.43 8.69 ± 3.91 10.63 ± 3.92 b.0011
405 (28.0) 202 (42.7) 60 (55.6) 12 (75.0) b.0012
1.0 1.92 (1.55–2.38) 3.22 (2.17–4.79) 7.73 (2.48–24.12) b.0012
⁎ P value as determined with the ANOVA1 and Chi-square test2; VMS score: 0: none, 1: mild, 2: moderate, and 3:severe.
240
D. Sun et al. / Journal of Psychosomatic Research 76 (2014) 237–241
OR
95% CI
392 413 348 893
1.0 1.28 1.70** 2.61**
0.92–1.77 1.22–2.37 1.97–3.43
Educational years b10 (primary school) 10–15 (middle school) N15 (university)
1000 183 863
1.0 0.51** 0.39**
0.37–0.71 0.28–0.54
Marital status Married Divorced/widowed Single
2011 31 4
1.0 0.96 0.35
0.45–2.04 0.16–1.02
741 844 461
1.0 0.95 0.64*
0.74–1.23 0.45–0.92
Body mass index, kg/m2 Low Normal Overweight Obese
65 1501 435 42
1.0 0.73 0.74 0.79
0.44–1.22 0.43–1.27 0.52–1.47
Current smoking No Yes
2038 8
1.0 1.87
0.39–8.87
Current drinking No Yes
2022 24
1.0 1.61
0.65–4.01
History of disease No Yes
1367 679
1.0 1.35*
1.08–1.68
increased in parallel with the intensity of vasomotor symptoms. The relationship between vasomotor symptoms and sleep disturbance has been reported in other studies [20,23]. Laboratory research has demonstrated that vasomotor symptoms were associated with cortical arousals and the disruption of sleep architecture, such as reduced sleep efficiency, increased nocturnal awakenings and changes in sleep stages [24,25]. However, the precise mechanisms through which hot flushes influence sleep disturbance are not well known. Sleep disturbance is often caused by hot flushes and sweating at night, which are associated with hormonal changes. Estrogen tends to decrease sleep latency, decrease the number of awakenings after sleep occurs, and increase total sleep time [26]. In addition, temperature regulation in the body is influenced by estrogen, and low levels are associated with increases in both peripheral and central temperatures, thereby resulting in hot flushes that are characteristic of menopause [27]. In addition to menopausal status and VMS, we found that general subject characteristics, such as older age and a history of disease, were independent risk factors for sleep disturbance according to the logistic regression analysis. Our findings are consistent with previous studies, which older age and a history of disease have been found as risk factors for sleep disturbance [12,18]. Older age has been associated with a 2-fold increase in the risk of sleep disturbance. A study in Korea demonstrated that sleep disturbance most frequently occurred in the elderly [18]. Age-related hormonal changes that occur with sleep architecture and sleep perception may contribute to the development of sleep disturbance. Women with chronic diseases reported more sleep disturbance than women without chronic diseases. Finally, this study confirmed that higher education and income levels exert a protective role against sleep disturbance, which has been reported in a study of Hispanic women [18,20]. Our study had several limitations. First, this study used a crosssectional design; therefore, the causality of the association could not be addressed. An additional longitudinal study is needed to determine the influence of menopause on sleep disturbance. Second, this study was based on only subjective assessments (e.g., the PSQI) of sleep quality. Subjective assessments may not always correlate with objective assessments (polysomnography) [28]. Nevertheless, objective assessments were unsuitable for this study due to their high cost and the high sample size of this study. Third, the survey instrument did not include an anxiety and depression rating scale. Therefore, we could not determine the relationship between sleep disturbance and anxiety and depression. However, previous studies have found that women with anxiety and depression symptoms reported more sleep disturbance [20]. Finally, we included both age and menopausal status in the analyses; however, there may have been overlap between the information that was obtained using the two variables and the effects of age and menopause are difficult to distinguish. In conclusion, sleep disturbance was highly prevalent in this large sample of middle-aged Chinese women. Menopausal status, VMS, menopausal symptom severity, a history of disease, and older age were important risk factors for sleep disturbance. Higher education and income levels were associated with better sleep quality. However, additional comprehensive research is needed to determine the factors that influence sleep disturbance. Finally, measures should be taken to improve the quality of life of middle-aged women.
Modified KI score Normal (≤6) Abnormal (N6)
678 1368
1.0 4.82**
3.74–6.22
Contributors
VMS No Yes
1449 597
1.0 1.25**
1.21–1.29
930 141 975
1.0 1.59** 1.23**
1.23–2.08 1.01–1.84
Table 5 Relationship between scores for modified KI (total and subscales) and sleep disturbance Sleep disturbance
Women number
Total KI score
Yes No P value⁎
679 1367
13.39 ± 6.27 8.23 ± 5.09 b.001
Modified KI subscales Somatic
Psychological
Urogenital
5.39 ± 4.13 3.32 ± 3.17 b.001
4.33 ± 2.05 2.39 ± 1.58 b.001
3.67 ± 2.93 2.53 ± 2.78 b.001
⁎ P value as determined with the Independent-Samples T Test.
found an association between sleep disturbance and being overweight or obese [5]. In this study, women with higher global PSQI scores had higher total and subscale KI scores (somatic, psychological, and urogenital); therefore, women with more severe symptoms experienced a worse quality of sleep. The findings in this study are consistent with those in a study in Colombia [22]. An interesting finding from this study was that vasomotor symptoms (hot flushes and sweating) were significantly associated with sleep disturbance. In addition, the prevalence of sleep disturbance
Table 6 Risk factors related to sleep disturbance Variables Age, years 40–44 45–49 50–54 55–60
Income (RMB/per month) b3000 3000–5000 N5000
Menopausal status Premenopause Perimenopause Postmenopause
N.
*P b .05,**P b .01, P value as determined with the logistic regression analysis.
Dongmei Sun and Minfang Tao assisted with the conception and design of the study. Dongmei Sun performed the data collection and the statistical analysis and drafted the manuscript. Hongfang Shao reviewed the manuscript. Changbin Li assisted with the data collection. Minfang Tao assisted with the interpretation of results and reviewed the manuscript. All of the authors have seen and approved the final version of the manuscript.
D. Sun et al. / Journal of Psychosomatic Research 76 (2014) 237–241
Conflict of interest statement The authors report no conflicts of interest in this work. Funding This research was supported by a grant from the Shanghai Science and Technology Commission (11411950103). Acknowledgments We would like to thank the women who participated in the study. References [1] 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;7:223–9. [2] Kravitz HM, Zhao X, Bromberger JT, Gold EB, Hall MH, Matthews KA, et al. Sleep disturbance during the menopausal transition in a multi-ethnic community sample of women. Sleep 2008;31:979–90. [3] Terauchi M, Obayashi S, Akiyoshi M, Kato K, Matsushima E, Kubota T. Insomnia in Japanese peri- and postmenopausal women. Climacteric 2010;13:479–86. [4] Sands-Lincoln M, Loucks EB, Lu B, Carskadon MA, Sharkey K, Stefanick ML, et al. Sleep duration, insomnia, and coronary heart disease among postmenopausal women in the Women's Health Initiative. J Womens Health (Larchmt) 2013;22:477–86. [5] Prather AA, Puterman E, Epel ES, Dhabhar FS. Poor sleep quality potentiates stressinduced cytokine reactivity in postmenopausal women with high visceral abdominal adiposity. Brain Behav Immun 2014;35:155–62. [6] Young T, Rabago D, Zgierska A, Austin D, Laurel F. Objective and subjective sleep quality in premenopausal, perimenopausal, and postmenopausal women in the Wisconsin Sleep Cohort Study. Sleep 2003;26:667–72. [7] Chung KF, Tang MK. Subjective sleep disturbance and its correlates in middle-aged Hong Kong Chinese women. Maturitas 2006;53:396–404. [8] Polo-Kantola P, Saaresranta T, Polo O. Aetiology and treatment of sleep disturbances during perimenopause and postmenopause. CNS Drugs 2001;15:445–52. [9] Cuadros JL, Fernandez-Alonso AM, Cuadros-Celorrio AM, Fernández-Luzón N, Guadix-Peinado MJ, Cid-Martín ND, et al. Perceived stress, insomnia and related factors in women around the menopause. Maturitas 2012;72:367–72.
241
[10] Cheng MH, Hsu CY, Wang SJ, Lee SJ, Wang PH, Fuh JL. The relationship of selfreported sleep disturbance, mood, and menopause in a community study. Menopause 2008;15:958–62. [11] Kawada T, Yosiaki S, Yasuo K, Suzuki S. Population study on the prevalence of insomnia and insomnia-related factors among Japanese women. Sleep Med 2003;4:563–7. [12] Kravitz HM, Ganz PA, Bromberger J, Powell LH, Sutton-Tyrrell K, Meyer PM. Sleep difficulty in women at midlife: a community survey of sleep and the menopausal transition. Menopause 2003;10:19–28. [13] Ohayon MM. Severe hot flashes are associated with chronic insomnia. Arch Intern Med 2006;166:1262–8. [14] Physical status: the use and interpretation of anthropometry. Report of a WHO Expert Committee. World Health Organ Tech Rep Ser 1995;854:1–452. [15] Liu X, Tang M, Hu L. Reliability and validity of the Pittsburgh sleep quality index. Chin J Psychiatry 1996;5:103–7. [16] Cao Z. Chinese obstetrics and gynecology. 2nd ed. Beijing: People's Republic of China: People's Medical Publishing House; 2005. [17] Timur S, Sahin NH. Effects of sleep disturbance on the quality of life of Turkish menopausal women: a population-based study. Maturitas 2009;64:177–81. [18] Shin C, Lee S, Lee T, Shin K, Yi H, Kimm K, et al. Prevalence of insomnia and its relationship to menopausal status in middle-aged Korean women. Psychiatry Clin Neurosci 2005;59:395–402. [19] Owens JF, Matthews KA. Sleep disturbance in healthy middle-aged women. Maturitas 1998;30:41–50. [20] Blumel JE, Cano A, Mezones-Holguin E, Baron G, Bencosme A, Benitez Z, et al. A multinational study of sleep disorders during female mid-life. Maturitas 2012;72:359–66. [21] Hajak G. Epidemiology of severe insomnia and its consequences in Germany. Eur Arch Psychiatry Clin Neurosci 2001;251:49–56. [22] Monterrosa-Castro A, Marrugo-Florez M, Romero-Perez I, Fernandez-Alonso AM, Chedraui P, Perez-Lopez FR. Assessment of sleep quality and correlates in a large cohort of Colombian women around menopause. Menopause 2013;20:464–9. [23] Arakane M, Castillo C, Rosero MF, Penafiel R, Perez-Lopez FR, Chedraui P. Factors relating to insomnia during the menopausal transition as evaluated by the Insomnia Severity Index. Maturitas 2011;69:157–61. [24] Polo-Kantola P. Sleep problems in midlife and beyond. Maturitas 2011;68:224–32. [25] Woodward S, Freedman RR. The thermoregulatory effects of menopausal hot flashes on sleep. Sleep 1994;17:497–501. [26] Miller EH. Women and insomnia. Clin Cornerstone 2004;6:S8–S18. [27] Eichling P. Evaluating and treating menopausal sleep problems. Menopause Manage 2002;11:8–17. [28] Vitiello MV, Larsen LH, Moe KE. Age-related sleep change: gender and estrogen effects on the subjective-objective sleep quality relationships of healthy, noncomplaining older men and women. J Psychosom Res 2004;56:503–10.
