Laura S. Castro

Objective prevalence of insomnia in the São Paulo, Brazil epidemiologic sleep study

Using polysomnography, the gold standard for sleep assessment, this study aimed to describe the objective prevalence of insomnia in the São Paulo, Brazil, Epidemiologic Sleep Study cohort of 1,101 adults (20–80 years old).

Effect of smoking habits on sleep

To evaluate the effect of smoking habits on sleep, data from 1492 adults referred to the Sleep Institute were accessed and divided into 3 categories of smoking status: current, former and non-smokers. Categories of pack-years (<15 and > or =15) defined smoking severity. The association of smoking status and smoking severity with sleep was analyzed for sleep parameters, especially apnea and hypopnea index (AHI) > or =5, more than 5% of total sleep time (TST) spent with oxyhemoglobin saturation (SaO2) <90%, and arousal index. The arousal index was higher among current (21 +/- 17) and former smokers (20 +/- 17) than non-smokers (17 +/- 15; P < 0.04). Former smokers had a higher percent of TST at SaO2 <90% than non-smokers (9 +/- 18 vs 6 +/- 13; P < 0.04). Former smokers with pack-years > or =15 compared to <15 exhibited higher AHI (22 +/- 24 vs 16 +/- 21; P < 0.05) and arousal index (22 +/- 19 vs 18 +/- 15; P < 0.05). Current smokers with pack-years > or =15 compared to <15 exhibited higher arousal index (23 +/- 18 vs 18 +/- 16; P < 0.05) and percent of TST at SaO2 <90% (11 +/- 17 vs 6 +/- 13; P < 0.05). Smoking status and pack-years were not associated with AHI > or =5 on logistic regression analysis, but current smokers with pack-years > or =15 were 1.9 times more likely to spend more than 5% of TST at SaO2 <90% than non-smokers (95%CI = 1.21-2.97; P = 0.005). The variability of arousal index was influenced by gender, AHI and current smokers with pack-years > or =15 (all P < 0.01). Smoking habits seem to be associated with arousal and oxyhemoglobin desaturation during sleep, but not with AHI. The effect was more pronounced in current than former smokers.

Sleep Apnea and Nocturnal Cardiac Arrhythmia: A Populational Study

Background The mechanisms associated with the cardiovascular consequences of obstructive sleep apnea include abrupt changes in autonomic tone, which can trigger cardiac arrhythmias. The authors hypothesized that nocturnal cardiac arrhythmia occurs more frequently in patients with obstructive sleep apnea. Objective To analyze the relationship between obstructive sleep apnea and abnormal heart rhythm during sleep in a population sample. Methods Cross-sectional study with 1,101 volunteers, who form a representative sample of the city of São Paulo. The overnight polysomnography was performed using an EMBLA® S7000 digital system during the regular sleep schedule of the individual. The electrocardiogram channel was extracted, duplicated, and then analyzed using a Holter (Cardio Smart®) system. Results A total of 767 participants (461 men) with a mean age of 42.00 ± 0.53 years, were included in the analysis. At least one type of nocturnal cardiac rhythm disturbance (atrial/ventricular arrhythmia or beat) was observed in 62.7% of the sample. The occurrence of nocturnal cardiac arrhythmias was more frequent with increased disease severity. Rhythm disturbance was observed in 53.3% of the sample without breathing sleep disorders, whereas 92.3% of patients with severe obstructive sleep apnea showed cardiac arrhythmia. Isolated atrial and ventricular ectopy was more frequent in patients with moderate/severe obstructive sleep apnea when compared to controls (p < 0.001). After controlling for potential confounding factors, age, sex and apnea-hypopnea index were associated with nocturnal cardiac arrhythmia. Conclusion Nocturnal cardiac arrhythmia occurs more frequently in patients with obstructive sleep apnea and the prevalence increases with disease severity. Age, sex, and the Apnea-hypopnea index were predictors of arrhythmia in this sample.

Sleep disorders and demand for medical services: evidence from a population-based longitudinal study.

Background The aim of this study was to investigate whether insomnia and obstructive sleep apnea (OSA) were predictors of hospitalizations or emergency department visits during two years following the Sao Paulo Epidemiologic Sleep Study (EPISONO) sample. Methods and Findings All participants (n = 1,101) who underwent a baseline evaluation between July and December 2007 were contacted in December 2009 and asked to fill out a questionnaire about body weight changes, number of hospitalizations and visits to the emergency department. Participants lost during the follow-up period represented 3.2% (n = 35) and 7 subjects had died. Hospitalizations were reported by 116 volunteers (10.5%) and emergency department visits were reported by 136 participants (12.4%). The average body mass index (BMI) did not vary significantly between the first and the second assessment [26.7(95%CI:26.3–27.1) vs. 26.9(26.5–27.4) kg/m2]. After adjusting for confounders, a multiple logistic regression model revealed that female gender [1.4(1.0–1.9)], age ≥40 years, insomnia diagnosed according to the DSM-IV criteria [1.6(1.0–2.6)], and apnea-hypopnea index ≥15 [1.5(1.0–2.2)] were predictors of hospitalizations and/or demand for emergency services. Conclusion Our study of a probabilistic sample of the Sao Paulo inhabitants shows that over a period of two years, insomnia and OSA were both associated with health impairment. Considering the high prevalence and public health burden of sleep disorders, the consequences of untreated disease for both the individual and society are undeniable and should be addressed.

Brain-derived neurotrophic factor gene polymorphism predicts interindividual variation in the sleep electroencephalogram.

Previous studies have suggested that brain‐derived neurotrophic factor (BDNF) participates in the homeostatic regulation of sleep. The objective of this study was to investigate the influence of the Val66Met functional polymorphism of the BDNF gene on sleep and sleep EEG parameters in a large population‐based sample. In total 337 individuals participating in the São Paulo Epidemiologic Sleep Study were selected for analysis. None of the participants had indications of a sleep disorder, as measured by full‐night polysomnography and questionnaire. Spectral analysis of the EEG was carried out in all individuals using fast Fourier transformation of the oscillatory signals for each EEG electrode. Sleep and sleep EEG parameters in individuals with the Val/Val genotype were compared with those in Met carriers (Val/Met and Met/Met genotypes). After correction for multiple comparisons and for potential confounding factors, Met carriers showed decreased spectral power in the alpha band in stage one and decreased theta power in stages two and three of nonrapid‐eye‐movement sleep, at the central recording electrode. No significant influence on sleep macrostructure was observed among the genotype groups. Thus, the Val66Met polymorphism seems to modulate the electrical activity of the brain, predicting interindividual variation of sleep EEG parameters. Further studies of this and other polymorphic variants in potential candidate genes will help the characterization of the molecular basis of sleep.

Depressive symptoms and sleep: a population-based polysomnographic study.

The goals of the present study were to determine the prevalence of depression in the adult population of Sao Paulo, Brazil and to explore the relationship among sociodemographic, physical and psychological factors, sleep-related symptoms and polysomnography parameters. Participants of a cross-sectional study (N = 1101) were administered questionnaires and submitted to polysomnography. A score > 20 in the Beck Depression Inventory was used to describe depression. Results revealed that the prevalence of depression was 10.9%. Estimates were higher in women and were significantly higher among housewives, non-workers and individuals with lower education and income. A combination of sleep-related symptoms and impaired quality of life was 2.5 times more frequent among depressed than non-depressed. Co-morbid insomnia and anxiety were positively associated to depressive symptomatology. There were no alterations in the polysomnography parameters, in either group. The occurrence of sleep apnea with values on the apnea-hypopnea index ≥ 5 was similar and frequent in both groups (around 30%). The findings suggest that depressive symptoms were associated with low education, low income, severe comorbid symptomatology, and impaired quality of life. Considering the high prevalence of sleep apnea, these results point to potential social and financial burdens associated with the depressive symptomatology and various sleep diagnoses.

Psychological Treatment for Sleepwalking: two case reports

Sleep architecture and polysomnographic findings show that the majority of sleepwalking episodes occur during slow-wave sleep (SWS).1–4 Although genetics play an important role in the manifestation of sleepwalking,5,6 recent studies have shown that parasomnias are also associated with other sleep or mental disorders3,7,10,11 and psychological factors.3,7,10–14 Sleepwalking prevalence rates are higher in childhood15 than in adulthood.10 Due to the risk of injuries3,4,10,16,17 beyond the presence of associated symptoms,4,8 those who suffer from sleepwalking often seek medical treatment. Treatment is commonly based on pharmacologic intervention,18–20 particularly the use of the benzodiazepinic drug clonazepam.4,19,20 However, some patients do not respond to this medication19 or present side effects.21 The aim of this report was to demonstrate psychological integrity and functioning as a correlate of a sleepwalking predisposition and to describe a sleep disorder-focused psychotherapy as an option for treating sleepwalking in adults that shows effects on sleep-related behaviors, psychological symptoms, and objective sleep data.

Concentration and variety of carbapenemase producers in recreational coastal waters showing distinct levels of pollution

ABSTRACT Carbapenemase-producing bacteria cause difficult-to-treat infections related to increased mortality in health care settings. Their occurrence has been reported in raw sewage, sewage-impacted rivers, and polluted coastal waters, which may indicate their spread to the community. We assessed the variety and concentration of carbapenemase producers in coastal waters with distinct pollution levels for 1 year. We describe various bacterial species producing distinct carbapenemases not only in unsuitable waters but also in waters considered suitable for primary contact.