Insomnia with Objective Short Sleep Duration is Associated with Deficits in Neuropsychological Performance: A General Population Study

Sleep Research and Treatment Center, Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
Sleep (Impact Factor: 4.59). 04/2010; 33(4):459-65.
Source: PubMed


To examine the joint effect of insomnia and objective short sleep duration on neuropsychological performance.
Representative cross-sectional study.
Sleep laboratory.
1,741 men and women randomly selected from central Pennsylvania.
Insomnia (n = 116) was defined by a complaint of insomnia with a duration > or = 1 year and the absence of sleep disordered breathing (SDB), while normal sleep (n = 562) was defined as the absence of insomnia, excessive daytime sleepiness, and SDB. Both groups were split according to polysomnographic sleep duration into 2 categories: > or = 6 h of sleep ("normal sleep duration") and < 6 h of sleep ("short sleep duration"). We compared the groups' performance on a comprehensive neuropsychological battery that measured processing speed, attention, visual memory, and verbal fluency, while controlling for age, race, gender, education, body mass index, and physical and mental health.
No significant differences were detected between insomniacs and controls. However, the insomnia with short sleep duration group compared to the control with normal or short sleep duration groups showed poorer neuropsychological performance in variables such as processing speed, set-switching attention, and number of visual memory errors and omissions. In contrast, the insomnia with normal sleep duration group showed no significant deficits.
Insomnia with objective short sleep duration is associated with deficits in set-switching attentional abilities, a key component of the "executive control of attention." These findings suggest that objective sleep duration may predict the severity of chronic insomnia, including its effect on neurocognitive function.

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Available from: Julio Fernandez-Mendoza
    • "Insomnia also is an independent risk factor for poor health (Irwin, 2015) and the most dramatic consequences arise when insomnia and short sleep duration coexist. Individuals with combined insomnia and PSG-defined short sleep duration (<6 h) have an increased risk of hypertension (Vgontzas et al., 2009a; Fernandez-Mendoza et al., 2012) and Type-2 Diabetes (Vgontzas et al., 2009b), and deficits in executive attention (Fernandez-Mendoza et al., 2010). The presence of PSG-defined short sleep duration (<6 h) in insomnia is a strong predictor of persistent insomnia years later (Vgontzas et al., 2012). "
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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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    • "The presence of sleep apnoea was defined as an obstructive apnoea/hypopnoea index ≥5 events per hour of sleep (Bixler et al., 2001). From the objectively recorded total sleep time data with a population median of 6 h (Fernandez-Mendoza et al., 2010, 2011, 2012a,b; Vgontzas et al., 2009a,b, 2010, 2012), we regrouped individuals in each age decade into two ordinal groups: the top 50% of persons above the median total sleep time ('normal sleep duration group') and the 50% of persons in the bottom half ('short sleep duration group'). Thus, we created the following two sleep duration groups: the 'normal sleep duration group' who slept on average 6.6 AE 0.6 h and the 'short sleep duration group' who slept on average 5.0 AE 1.1 h. "
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    ABSTRACT: Longitudinal studies that have examined the association of insomnia with incident depression using objective sleep measures are very limited. The aim of this study was to examine the predictive role of the severity of insomnia for incident depression in a general population sample using psychometric and polysomnographic data. From a random, general population sample of 1741 individuals of the Penn State Adult Cohort, 1137 adults without depression were followed up with a structured telephone interview after 7.5 years. All subjects completed a full medical evaluation, 1-night polysomnogram and Multiphasic Minnesota Personality Inventory at baseline. The incidence of depression was 15%. Poor sleep (odds ratio = 1.5, P = 0.001) and insomnia (odds ratio = 1.9, P = 0.031) were significantly associated with incident depression. The odds of incident depression were highest (odds ratio = 2.2, P = 0.019) in insomnia with objective short sleep duration and independent of Multiphasic Minnesota Personality Inventory Ego Strength scores, an index of poor coping resources. The persistence of insomnia and worsening of poor sleep into insomnia significantly increased the odds of incident depression (odds ratios ranged from 1.8 to 6.3), whereas their full remission did not (odds ratio ranged from 1.2 to 1.8). Insomnia with short sleep duration is associated with incident depression independent of poor coping resources, whereas the association of insomnia with normal sleep duration with incident depression was mediated by poor coping resources. Persistence and worsening of poor sleep or insomnia, but not their full remission, are significant predictors of incident depression. These data suggest that there is a significant relationship between the severity of insomnia and incident depression. © 2015 European Sleep Research Society.
    Full-text · Article · Feb 2015 · Journal of Sleep Research
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    • "Insomnia is one of the most common sleep disorders, with prevalence rates in general populations reportedly ranging from 12.8% to 38.3%,1,2,3 including 22.8% in Koreans.4 Insomnia can cause impairment of several daytime cognitive functions (e.g., attention, concentration, and memory)5 that can lower efficiency at work6,7 and increase the risks of injuries and traffic collisions6,8 and of falls in older adults.9 Insomnia is also a prevalent complaint in clinical practice that can present with several other comorbid medical or psychiatric disorders.10 "
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    ABSTRACT: Background and Purpose The purposes of this study were to standardize and validate a Korean version of the Insomnia Severity Index (ISI-K), and to evaluate its clinical usefulness. Methods We translated the ISI into Korean and then translated it back into English to check its accuracy. The 614 patients with sleep disorders who were enrolled in this study comprised 169 with primary insomnia, 133 with comorbid insomnia, and 312 with obstructive sleep apnea. All subjects underwent one night of polysomnography (PSG) and completed the Korean versions of both the Pittsburgh Sleep Quality Index (PSQI-K) and the Epworth Sleepiness Scale, as well as the ISI-K. The ISI-K was compared to these sleep scales and various PSG sleep parameters. Results The internal consistency the ISI-K total score was confirmed by a Cronbach's alpha of 0.92, and the item-to-total-score correlations (item-total correlations) ranged from 0.65 to 0.84, suggesting adequate reliability. The correlation between the ISI-K total score and PSQI-K was 0.84, which suggested adequate convergent validity. Low-to-moderate correlations were obtained between the ISI-K total score and PSG-defined sleep parameters: 0.22 for sleep onset latency, 0.38 for wake after sleep onset, and 0.46 for sleep efficiency. A cutoff score of 15.5 on the ISI-K was optimal for discriminating patients with insomnia. The test-retest scores over a 4-week interval with 34 subjects yielded a correlation coefficient of 0.86, suggesting excellent temporal stability. Conclusions The findings of this study show that the ISI-K is a reliable and valid instrument for assessing the severity of insomnia in a Korean population.
    Full-text · Article · Jul 2014 · Journal of Clinical Neurology
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