Severe Hot Flashes Are Associated With Chronic Insomnia

Stanford Sleep Epidemiology Research Center, Stanford University School of Medicine, 3430 W. Bayshore Road, Palo Alto, CA 94303, USA.
Archives of Internal Medicine (Impact Factor: 17.33). 07/2006; 166(12):1262-8. DOI: 10.1001/archinte.166.12.1262
Source: PubMed


Because hot flashes can occur during the night, their presence has been frequently associated with insomnia in women with symptoms of menopause. However, many factors other than hot flashes or menopause can be responsible for insomnia, and several factors associated with insomnia in the general population are also commonly observed in perimenopausal and postmenopausal women who have hot flashes.
A random sample of 3243 subjects (aged > or =18 years) representative of the California population was interviewed by telephone. Included were 982 women aged 35 to 65 years. Women were divided into 3 groups according to menopausal status: premenopause (57.2%), perimenopause (22.3%), and postmenopause (20.5%). Hot flashes were counted if they were present for at least 3 days per week during the last month and were classified as mild, moderate, or severe according to their effect on daily functioning. Chronic insomnia was defined as global sleep dissatisfaction, difficulty initiating sleep, difficulty maintaining sleep, or nonrestorative sleep, for at least 6 months. Diagnoses of insomnia were assessed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, classification.
Prevalence of hot flashes was 12.5% in premenopause, 79.0% in perimenopause, and 39.3% in postmenopause. Prevalence of chronic insomnia was reported as 36.5% in premenopause, 56.6% in perimenopause, and 50.7% in postmenopause (P<.001). Prevalence of symptoms of chronic insomnia increased with the severity of hot flashes, reaching more than 80% in perimenopausal women and postmenopausal women who had severe hot flashes. In multivariate analyses, severe hot flashes were significantly associated with symptoms and a diagnosis of chronic insomnia. Poor health, chronic pain, and sleep apnea were other significant factors associated with chronic insomnia.
Severe hot flashes are strongly associated with chronic insomnia in midlife women. The presence of hot flashes should be systematically investigated in women with insomnia. Treating hot flashes could improve sleep quality and minimize the deleterious consequences of chronic insomnia.

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    • "They also had more wakefulness after sleep onset (WASO) and poorer sleep efficiency compared with controls (Baker et al., 2015). Sleep difficulties and insomnia disorder in the menopausal transition have been linked to several factors, including changing reproductive hormone levels (decrease in estradiol and increase in follicle stimulating hormone) (de Zambotti et al., 2015a; Kravitz et al., 2008), hot flashes (Baker et al., 2015; Kravitz et al., 2008; Ohayon, 2006), and psychosocial factors (Sassoon et al., 2014; Woods and Mitchell, 2010). Another important factor that could contribute to the development and/or exacerbation of insomnia in midlife women is susceptibility to stress. "
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    ABSTRACT: Hot flashes, hormones, and psychosocial factors contribute to insomnia risk in the context of the menopausal transition. Stress is a well-recognized factor implicated in the pathophysiology of insomnia; however the impact of stress on sleep and sleep-related processes in perimenopausal women remains largely unknown. We investigated the effect of an acute experimental stress (impending Trier Social Stress Task in the morning) on pre-sleep measures of cortisol and autonomic arousal in perimenopausal women with and without insomnia that developed in the context of the menopausal transition. In addition, we assessed the macro- and micro-structure of sleep and autonomic functioning during sleep. Following adaptation to the laboratory, twenty two women with (age: 50.4 ± 3.2 years) and eighteen women without (age: 48.5 ± 2.3 years) insomnia had two randomized in-lab overnight recordings: baseline and stress nights. Anticipation of the task resulted in higher pre-sleep salivary cortisol levels and perceived tension, faster heart rate and lower vagal activity, based on heart rate variability measures, in both groups of women. The effect of the stress manipulation on the autonomic nervous system extended into the first 4 h of the night in both groups. However, vagal tone recovered 4–6 h into the stress night in controls but not in the insomnia group. Sleep macrostructure was largely unaltered by the stress, apart from a delayed latency to REM sleep in both groups. Quantitative analysis of non-rapid eye movement sleep microstructure revealed greater electroencephalographic (EEG) power in the beta1 range (15–≤23 Hz), reflecting greater EEG arousal during sleep, on the stress night compared to baseline, in the insomnia group. Hot flash frequency remained similar on both nights for both groups. These results show that pre-sleep stress impacts autonomic nervous system functioning before and during sleep in perimenopausal women with and without insomnia. Findings also indicate that women with insomnia had increased EEG arousal and lacked recovery in vagal activity across the stress night suggesting a greater sensitivity to stress in this group.
    No preview · Article · Dec 2015 · Psychoneuroendocrinology
    • "Together with hot flashes/night sweats, feeling tired and weight gain, sleep problems are the most common symptoms women discuss with their healthcare providers (Williams et al., 2007). In 26% of perimenopausal women (a prevalence that is higher than in premenopausal or postmenopausal women), sleep disturbances cause significant distress and impact women's daytime functioning qualifying them for a diagnosis of insomnia disorder (Ohayon, 2006). "
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    ABSTRACT: The menopausal transition is marked by increased prevalence in disturbed sleep and insomnia, present in 40-60% of women, but evidence for a physiological basis for their sleep complaints is lacking. We aimed to quantify sleep disturbance and the underlying contribution of objective hot flashes in 72 women (age range: 43-57 years) who had (38 women), compared to those who had not (34 women), developed clinical insomnia in association with the menopausal transition. Sleep quality was assessed with two weeks of sleep diaries and one laboratory polysomnographic (PSG) recording. In multiple regression models controlling for menopausal transition stage, menstrual cycle phase, depression symptoms, and presence of objective hot flashes, a diagnosis of insomnia predicted PSG-measured total sleep time (p<0.01), sleep efficiency (p=0.01) and wakefulness after sleep onset (WASO) (p=0.01). Women with insomnia had, on average, 43.5min less PSG-measured sleep time (p<0.001). There was little evidence of cortical EEG hyperarousal in insomniacs apart from elevated beta EEG power during REM sleep. Estradiol and follicle stimulating hormone levels were unrelated to beta EEG power but were associated with the frequency of hot flashes. Insomniacs were more likely to have physiological hot flashes, and the presence of hot flashes predicted the number of PSG-awakenings per hour of sleep (p=0.03). From diaries, women with insomnia reported more WASO (p=0.002), more night-to-night variability in WASO (p<0.002) and more hot flashes (p=0.012) compared with controls. Women who develop insomnia in the approach to menopause have a measurable sleep deficit, with almost 50% of the sample having less than 6h of sleep. Compromised sleep that develops in the context of the menopausal transition should be addressed, taking into account unique aspects of menopause like hot flashes, to avoid the known negative health consequences associated with insufficient sleep and insomnia in midlife women.
    No preview · Article · Jun 2015 · Psychoneuroendocrinology
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    • "Gender differences in sleep disturbances have repeatedly demonstrated a greater frequency of sleep complaints in women than in men [1] [2] [3], which has often been attributed to hormonal changes, particularly during the midlife years [4] [5] [6] [7]. Increasing age has also been associated with increased frequency of sleep disturbance; however, this relationship is considerably modified when screening for comorbidity [2] [8] and depends on the specific definition provided for the assessment of sleep disturbance [1] [9]. "
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    ABSTRACT: Objectives/Background: We assessed prevalence and correlates of insomnia; associations between changes in insomnia with incidence of physical, emotional, and mixed impairments (PI, EI, and MI, respectively); and age as a moderator in these relationships. Participants/Methods: TheWomen’s Health Initiative (WHI) clinical trial (CT) and observational study (OS) cohorts with 1- and 3-year follow-ups, respectively, were studied. Participants included 39,864 CT and 53,668 OS postmenopausal women free of PI or EI at baseline. Insomnia Rating Scale (IRS), with a cutoff score of ≥9 indicated insomnia. Normal–Normal, Abnormal–Abnormal, Normal–Abnormal, and Abnormal– Normal categories indicated change in insomnia over time. PI, EI, and MI were constructed using Short Form-36 (SF-36) Physical and Emotional subscales (cutoff ≤60) and the modified Center for Epidemiological Studies Depression scale (cutoff ≤0.06). Results: Among 93,532 women, 24.5% had insomnia at baseline. The highest odds ratios (ORs) for impairments were found in the Normal–Abnormal and Abnormal–Abnormal categories. In the CT cohort, Normal–Abnormal category, ORs were 1.86 (95% CI = 1.57–2.20) for PI, 4.11 (95% CI = 3.59–4.72) for EI, and 6.37 (95% CI = 4.65–8.74) for MI. Respective ORs for the OS cohort were 1.70 (95% CI = 1.51–1.89), 3.80 (95% CI = 3.39–4.25), and 4.41 (95% CI = 3.56–5.46). Interactions between changes in insomnia and age showed distinct albeit nonsignificant patterns. Conclusions: The results suggest that exposure to insomnia increases vulnerability to impairment. Future studies are needed to understand the directionality of these relationships.
    Full-text · Article · Jan 2015 · Sleep Medicine
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