OBJECTIVES: The main objective of this study was to describe clinical features, particularly depressive symptoms, comorbidities, and polysomnographic characteristics of heavy drinkers with sleep disordered breathing (SDB).
METHODS: This was a cross-sectional study of 140 cases (92 males; mean age 54.6±8.2 years) referred for overnight polysomnography with suspicion of obstructive sleep apnea (OSA). Patients were questioned about clinical and demographic data and evaluated for depressive symptoms by the 17-item Hamilton Rating Scale for Depression (HRSD), excessive daytime sleepiness by the Epworth Sleepiness Scale (ESS) and comorbidity severity by the Charlson Comorbidity Index (CCI).
RESULTS: Fourteen patients were primary snorers [Apnea-Hypopnea Index (AHI≤5); 10%] and 126 had OSA (AHI>5): 86 (61.4%) moderate/severe type (AHI>15). Heavy drinking was more common in male (p<0.005) and younger (p=0.01) individuals. Among heavy drinkers, there was a correlation between depressive symptoms and body mass index (BMI) (r=0.33; p=0.01) and this was more evident in women (r=0.68; p<0.005) than in men (r=0.53; p=0.02). Excessive daytime sleepiness (ESS≥10) was present in 57 cases (40.7%). ESS scores were positively correlated with arousals (r=0.24; p=0.02) and negatively with SpO_2min (r= -0.18; p=0.03). Heavy drinkers with AHI<15 presented higher ESS scores (p=0.03) and a trend of association remained after controlling for age and gender (p=0.08).
CONCLUSIONS: In patients referred for polysomnography, heavy drinking is more common in younger male individuals. Depressive symptoms are related to BMI in heavy drinkers. More studies are warranted to clarify the influence of chronic heavy drinking on sleep abnormalities.

Keywords: Sleep apnea syndromes; Alcohol drinking; Alcohol beverages; Polysomnography; Comorbidity; Depression; Body mass index; Disorders of excessive somnolence

OBJECTIVE: To evaluate the prevalence of obesity and weight changes in night shift workers and their relationship with sleep.
METHODS: Fifty night shift and twenty-six day shift workers were evaluated. They belonged to one of two groups: nurse technicians/assistants or nurses. The night shift started at 7:00 p.m. and ended at 7:00 a.m., while the day shift was either from 7:00 a.m. to 1:00 p.m. or from 1:00 p.m. to 7:00 p.m. Data were collected using sleep diaries, personal questionnaires, scales to measure weight, and height measurement to calculate body mass index (BMI).
RESULTS: There were significant differences between the day shift and the night shift groups in sleep latency (6m54s and 20m6s; p<0.001), wakeup call (6h25m and 7h52m; p<0.001), sleep duration (7h12m and 8h21m; p=0.002), quality of nocturnal sleep (8.48 and 7.62; p=0.009), and total nap time (34m48s and 1h30m; p=0.001), respectively. The average BMI-1 (24.57; p=0.015) and BMI-2 (25.63; p=0.033) values from the day shift group were lower than those of the night shift group - BMI-1 (27.01) and BMI-2 (28.04). The frequency of physical activity was correlated with the difference in BMI (r=-0.296; p=0.0366).
CONCLUSIONS: The night shift workers showed a higher average BMI than day shift workers did. However, it was not possible to ascertain whether sleep alterations influenced the weight gain of night shift workers.

Keywords: Night work; Body mass index; Body weight; Personnel staffing and scheduling; Weight gain; Work schedule tolerance; Obesity; Sleep deprivation

OBJECTIVE: Medical emergency units have increasingly to deal with seizures associated with cocaine abuse, which are seen as a determinant of cocaine-related lethality in humans. Cocaine is an excitatory drug that inhibits catecholamine reuptake and induces sleep deprivation. In view of the fact that stress plays an important role in modulating drug action, the aim of this study was to compare whether paradoxical sleep deprivation and other modalities of chronic stress influence the proportion of cocaine-induced seizures in male rats.
METHODS: The incidence of seizures was measured for 60 minutes after acute administration of cocaine to rats (40, 45, 50 and 70 mg/kg) that have been submitted to different modalities of stress (paradoxical sleep deprivation, footshock, swimming and immobilization), applied repeatedly for 4 days, and then compared with non-stressed rats.
RESULTS:Cocaine induced seizures in 10% of control rats, and among stressful events this effect was potentiated only by paradoxical sleep deprivation, since 90% of the rats had seizures.
CONCLUSION: Our data show that selective sleep loss triggers a marked increase in the number of cocaine-induced seizures, suggesting that the absence of sleep per se has a relevant effect in modulating such events.

Keywords: Sleep deprivation; Cocaine/adverse effects; Seizures; Stress, psychological; Dopamine; Disease models, animal; Rats

ABSTRACT

OBJECTIVE: Breath perturbations associated with sleep are accompanied by cortical micro-awakenings. Seventy per cent of them are visible by direct observation on the polysomnographic study. The remaining may be evaluated using techniques such as neural networks or by spectral analysis using Fourier's method. The objective was to establish whether the application of a dynamic mathematical method for polysomnographic tracing enables the identification of an association frequency of the electroencephalogram and the electrocardiogram as a response to breathing events.
METHODS: Polysomnographs of 22 patients (14 males and 8 females) with sleep disordered breathing (SDB) and 3 normal subjects (2 males and 1 female). In order to establish the relationship between cortical activation (micro-awakening) and the electrocardiographic (ECG), both signals were analyzed. The mathematical method used consisted of a wavelet band decomposition of the electroencephalographic (EEG) and the ECG signals together with wavelet coherence.
RESULTS: The most evident synchronisation pattern occurred between the ECG band corresponding to the high frequencies QRS complex and the EEG alpha band. A correlation was found between the micro-awakening frequency and the frequency of the maximum values of the correlation between the EEG alpha band and the ECG fast band. These frequencies represent synchronization times between 1.5 and 2.8 seconds.
CONCLUSION: Above a cut point of 40 micro-awakenings/hour, the population with a significant myocardial activity was grouped showing a significant autonomic activity detectable in the polysomnographic tracing. When sleep fragmentation level is high, a significant myocardial activation appears.

Keywords: Sleep apnea syndromes/diagnosis; Sleep disorders; Polysomnography; Fourier analysis; Electroencephalography; Electrocardiography

The relationship between sleep and behavioral changes is quite clear. There are many neuro-behavioral co-morbidities that are related to sleep. In line with the aims of translational science, pre-clinical research has been shown to have great value for psychiatric research in Brazil and worldwide, and this importance can be extended to sleep studies. Thus, the present article aimed to present a broad view of basic behavioral science, especially the research using animal models, and focused on the global research output on the subject of "sleep", study trends and the Brazilian contribution to the field. The presented data demonstrate the increasing importance of Brazilian research to the field of sleep research, the Brazilian contribution to the worldwide knowledge of this subject and the adequacy of this theme to knowledge formation in the country, which is growing both in volume and publication relevance.

Keywords: Sleep; Behavioral research; Brazil

After an extensive literature review of sleep recording practices, the American Academy of Sleep Medicine recently published a new manual for sleep scoring and the recording of associated events in the routine sleep laboratory. This article presents and discusses the major changes that are suggested by the new manual compared to the recommendations previously practiced by most clinical and experimental investigators of human sleep.

Keywords: Sleep stages; Sleep/physiology; Electroencephalography; Polysomnography; Sleep disorders; Reference values; Practice guidelines as topic