Antonio Vela-Bueno

Short sleep duration and obesity: the role of emotional stress and sleep disturbances

Objective: Many epidemiologic studies have reported that obesity is associated with short sleep duration. How the degree of obesity or other clinical characteristics of the obese individuals, such as sleep disturbances or emotional stress, define this relation is not known.Design: We studied a random sample of 1300 middle-aged men and women from the Penn State Cohort in the sleep laboratory for one night. Sleep disturbances were recorded as insomnia, excessive daytime sleepiness (EDS) or sleep difficulty. Chronic emotional stress was determined by the Minnesota Multiphasic Personality Inventory-2 (MMPI-2).Results: Obese individuals (body mass index, BMI>30) reported shorter duration of sleep, had a higher incidence of subjective sleep disturbances (47.4 vs 25.5%; P<0.01) and scored higher for chronic emotional stress than nonobese subjects. However, there was no difference in self-reported sleep duration between obese and nonobese individuals without subjective sleep disturbances, while both obese men and women with sleep complaints scored higher in the MMPI-2 compared to obese individuals without sleep complaints. The shortest sleep duration was reported by the obese insomniac patients (5.9u2009h), followed by obese with EDS (6.3u2009h) or sleep difficulty (6.6u2009h). The effect of chronic emotional stress was stronger than that of the BMI on the reported sleep duration, with a synergistic joint effect. The presence of a sleep disturbance was associated with a reduction of reported sleep by 18u2009min for men and 42u2009min in women, whereas a 10u2009kgu2009m−2 increase of BMI was associated with a 16 and 6u2009min decrease of sleep in men and women, respectively. Interestingly, there was no association between objective sleep duration and BMI.Conclusion: Self-reported short sleep duration in obese individuals may be a surrogate marker of emotional stress and subjective sleep disturbances, whose detection and management should be the focus of our preventive and therapeutic strategies for obesity.

Insomnia and sleep quality among primary care physicians with low and high burnout levels

OBJECTIVEnThe aim of this study was to assess insomnia and sleep quality in primary care physicians with low and high burnout scores.nnnMETHODSnA representative sample of 240 physicians was drawn from 70 medical centers in Madrid, Spain. Based on quartile splits of the overall index of the Shirom-Melamed Burnout Questionnaire, 55 participants were allocated to a low-burnout group, and 58 were included in a high-burnout group. The questionnaire also included sociodemographic data, insomnia symptomatology, and the Pittsburgh Sleep Quality Index.nnnRESULTSnOf the total sample, 18.8% met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for insomnia diagnoses. More individuals with high burnout scores (21.1%) than individuals with low burnout scores (6.9%) fulfilled these criteria. Results of multivariate logistic regression analyses showed that burnout was the only variable related to insomnia diagnoses (odds ratio=7.56; 95% confidence interval=2.38-14.02). Furthermore, the results of multivariate analysis of covariance, after adjustments for sociodemographic variables, indicated that subjects from the high-burnout group scored significantly higher than subjects from the low-burnout group on the global sleep quality index and its components, indicating significantly greater disturbed sleep for the former.nnnCONCLUSIONnThe results of the present study provide support for a clear relationship between burnout and disturbed sleep, as shown by the high prevalence of insomnia and poor sleep quality among physicians with high levels of burnout.

Nighttime sleep and daytime functioning correlates of the insomnia complaint in young adults.

The nighttime and daytime correlates of the insomnia complaint (IC) were assessed in an in-class survey on a sample of 1238 first year university students (18.85+/-1.45 years) at the Universidad Autónoma of Madrid, Spain. Evidence was found that the likelihood of complaining of insomnia was increased by perceiving difficulties with initiating and maintaining sleep, reporting low quality of nocturnal sleep, having a long sleep onset latency and having an evening circadian preference. The most strongly related daytime variables to IC being perceived difficulties in concentrating, feelings of irritability and fatigue, and symptoms of anxiety and depression. The data, in addition to confirm those of clinical studies on subjects complaining of insomnia, suggest that having an evening chronotype increases the vulnerability of adolescents and young adults to complain of insomnia.

Sleepwalking and Night Terrors in Adulthood Clinical EEG Findings

This is the first controlled study to show a lack of relation between a positive history of sleepwalking or night terrors in adults and daytime EEG abnormalities. We recorded a standard clinical EEG on 35 adult sleepwalkers (SW), 35 adult night terror patients (NT), and 35 control subjects (CS). Three subjects in the SW group showed abnormalities: one during both the resting record (RR) and hyperventilation (HV), and two only during HV. None in the NT group showed any EEG abnormality. Two control subjects showed abnormalities of both RR and HV, and a third only during HV. The number of abnormal EEGs within each group was limited, and the three groups did not significantly differ from one another. Our results suggest that the daytime clinical EEG is of limited value in evaluating adults with the primary complaint of sleepwalking or night terrors. However, further all-night sleep EEG studies utilizing clinical montage are needed to investigate the temporal relationship of sleepwalking and night terror events to possible EEG abnormalities.

The Spanish version of the Insomnia Severity Index: A confirmatory factor analysis

OBJECTIVEnTo examine the psychometric properties of the Spanish version of the Insomnia Severity Index (ISI) and to determine its factor structure with confirmatory factor analysis (CFA).nnnMETHODSnSelf-reported information was collected from a sample of 500 adults (mean age 39.13 [standard deviation 15.85]years) drawn from a population of medical students and their social networks. Together with the ISI, a measure of the subjective severity of insomnia, subjects completed the Pittsburg Sleep Quality Index, the Epworth Sleepiness Scale, and the Profile of Mood States to study concurrent validity of the ISI. CFA was used to test alternative models to ascertain the factorial structure of the ISI.nnnRESULTSnThe Spanish version of the ISI showed adequate indices of internal consistency (Cronbachs α=0.82). CFA showed that a three-factor structure provided a better fit to the data than one-factor and two-factor structures. The ISI was significantly correlated with poor sleep quality, fatigue, anxiety, and depression, and discriminated between good and poor sleepers.nnnCONCLUSIONSnThe ISI is a reliable and valid instrument to assess the subjective severity of insomnia in Spanish-speaking populations. Its three-factor structure (i.e., night-time sleep difficulties, sleep dissatisfaction and daytime impact of insomnia) makes it a psychometrically robust and clinically useful measure.

Familial recurrent hypersomnia: two siblings with Kleine-Levin syndrome and menstrual-related hypersomnia.

Kleine-Levin syndrome and menstrual-related hypersomnia are rare idiopathic sleep disorders occurring primarily in adolescence. They are characterized by intermittent periods of excessive sleepiness, cognitive disturbances, and behavioral abnormalities. In both, the etiology remains unknown but autoinmune, hormonal, infectious, and inflammatory mechanisms have been proposed. The authors describe, for the first time, the association of Kleine-Levin syndrome and menstrual-related hypersomnia in 2 adolescent siblings who shared the human leukocyte antigen (HLA) loci DQB1*0501. The same haplotype has been associated with sleepwalking and with rapid eye movement (REM) sleep behavior disorder. This gender differences in the manifestation of a probably genetic influenced sleep disorder suggests that hormonal mechanisms could be implicated in the phenotypical expression of this sleep disorder. The male sibling with Kleine-Levin syndrome was easily controlled with carbamazepine in low doses, but his sister could be only efficaciously treated with oral contraceptives.

Narcolepsy-cataplexy and loss of sphincter control.

We describe the case of a 34-year-old man who presented intermittent faecal incontinence as a manifestation of cataplexy. The patients sleep history was positive for the full narcoleptic tetrad (sleep attacks, cataplexy, sleep paralysis and hypnagogic hallucinations) while extensive neuropsychiatric work up was negative for any neurologic or psychiatric illness. Repeat polysomnograms (including a polysomnogram with a full seizure montage) were positive for pathologic sleepiness, but there was no evidence of a seizure disorder. The course of the patients symptomatology and the favourable response of his symptoms to stimulants and imipramine support the theory that his intermittent loss of sphincter control is part of his narcolepsy-cataplexy.

Insomnia With Objective Short Sleep Duration and Incident Hypertension

Insomnia with objective short sleep duration appears to be a biologically more severe phenotype of the disorder. No longitudinal study to date has examined the association of this type of insomnia with incident hypertension using polysomnography. From a random, general population sample of 1741 adults of the Penn State Cohort, 1395 were followed-up after 7.5 years, and 786 did not have hypertension at baseline. Hypertension was determined by a self-report of receiving treatment for high blood pressure. Chronic insomnia was defined as a complaint of insomnia lasting ≥1 year, whereas poor sleep was defined as moderate-to-severe sleep difficulties. All of the subjects underwent 8-hour polysomnography. Sleep-disordered breathing (SDB) was defined as an obstructive apnea/hypopnea index ≥5. We used the median polysomnographic percentage of sleep time to define short sleep duration (ie, <6 hours). We controlled for sex, race, age, caffeine, cigarettes and alcohol consumption, depression, sleep-disordered breathing, diabetes mellitus, obesity, and blood pressure in our analyses. Compared with normal sleepers who slept ≥6 hours, the highest risk for incident hypertension was in chronic insomniacs with short sleep duration (odds ratio, 3.8 [95% CI, 1.6–9.0]). The risk for incident hypertension in poor sleepers with short sleep duration was significantly increased but became marginally significant after controlling for obesity (odds ratio, 1.6 [95% CI, 0.9–2.8]). Chronic insomnia with short sleep duration is associated with an increased risk for incident hypertension in a degree comparable to sleep-disordered breathing. Objective short sleep duration in insomnia may serve as a useful predictor of the biological severity of the disorder.

Insomnia With Objective Short Sleep Duration and Incident Hypertension: The Penn State Cohort * Novelty and Significance

Insomnia with objective short sleep duration appears to be a biologically more severe phenotype of the disorder. No longitudinal study to date has examined the association of this type of insomnia with incident hypertension using polysomnography. From a random, general population sample of 1741 adults of the Penn State Cohort, 1395 were followed-up after 7.5 years, and 786 did not have hypertension at baseline. Hypertension was determined by a self-report of receiving treatment for high blood pressure. Chronic insomnia was defined as a complaint of insomnia lasting ≥1 year, whereas poor sleep was defined as moderate-to-severe sleep difficulties. All of the subjects underwent 8-hour polysomnography. Sleep-disordered breathing (SDB) was defined as an obstructive apnea/hypopnea index ≥5. We used the median polysomnographic percentage of sleep time to define short sleep duration (ie, <6 hours). We controlled for sex, race, age, caffeine, cigarettes and alcohol consumption, depression, sleep-disordered breathing, diabetes mellitus, obesity, and blood pressure in our analyses. Compared with normal sleepers who slept ≥6 hours, the highest risk for incident hypertension was in chronic insomniacs with short sleep duration (odds ratio, 3.8 [95% CI, 1.6–9.0]). The risk for incident hypertension in poor sleepers with short sleep duration was significantly increased but became marginally significant after controlling for obesity (odds ratio, 1.6 [95% CI, 0.9–2.8]). Chronic insomnia with short sleep duration is associated with an increased risk for incident hypertension in a degree comparable to sleep-disordered breathing. Objective short sleep duration in insomnia may serve as a useful predictor of the biological severity of the disorder.