S. Garbuio

Sleep complaints in the Brazilian population: Impact of socioeconomic factors

National surveys are relevant for the study of sleep epidemiology since they can provide specific data about sleep in large dimension with important implications for the health system. Thus, the aim of this study was to investigate the prevalence of sleep complaints among the Brazilian population using a randomized cluster sample according to region and socioeconomic class. For this, a 3-stage sampling technique was used to randomly select Brazilian subjects of both genders older than 16 years. A total of 2017 subjects, from 132 different cities, were selected to estimate prevalence in the Brazilian population with a sampling error of ±2%. Questions about sleep complaints were administered face-to-face by Instituto Datafolha interviewers on April 10 and 16, 2012. Data were expanded using a weighted variable. The results showed that 76% of the study population suffers from at least 1 sleep complaint, indicating that approximately 108 million Brazilians may be affected by sleep disorders. On average, each subject had 1.9 sleep problems with the most common complaints being light and insufficient sleep, snoring, moving a lot during sleep, and insomnia, which usually occurred more than 3 times per week. Low income was associated with higher number of sleep complaints only in Northeast and Southeast regions. In conclusion, this study showed a high prevalence of sleep complaints in a sample of the Brazilian population, suggesting that sleep disorders may be markedly frequent in the Brazilian population with a possible correlation with the socioeconomic situation of the interviewed subjects.

Late-onset, insidious course and invasive treatment of congenital central hypoventilation syndrome in a case with the Phox2B mutation: case report

Congenital central hypoventilation syndrome (CCHS) is a rare disorder of respiratory control characterized by ventilatory impairment that results in arterial hypoxemia. This condition is worse during sleep and occurs in patients with normal mechanical properties of the lung. It is diagnosed in the absence of primary neuromuscular disease, identifiable brainstem lesions, and other sleep disturbances or substance use [1]. Amiel et al. [2] identified a mutation in the Phox2B gene associated with CCHS, characterized by five to nine alanine expansions within a 20-residue polyalanine region in exon 3 of the Phox2B gene. Several reports confirmed the findings of Amiel et al., supporting the view that this gene is a master switch for the development of the autonomic nervous system network linked to respiratory control [3–6]. Transgenic animals carrying the human Phox2B mutation develop a similar phenotype and lack glutamatergic neurons located in the parafacial region in the brainstem, which are involved in breathing control [7]. Although patients typically present with CCHS as newborns and rarely in later infancy, there have been reports of patients presenting with CCHS in adulthood. In cases of late-onset CCHS, most patients report having had some symptoms since childhood, and they have parents with a history of CCHS. Symptoms of right-sided heart failure are generally observed at the time of diagnosis, and nocturnal noninvasive ventilation is frequently indicated [8–15]. L. R. A. Bittencourt (*) :M. Pedrazzoli : F. Yagihara : G. P. Luz : S. Garbuio :G. A. Moreira : S. Tufik Disciplina de Medicina e Biologia do Sono, Departamento de Psicobiologia, Universidade Federal de Sao Paulo, Rua Napoleao de Barros, 925, 04024-002 Sao Paulo, Sao Paulo, Brazil e-mail: lia@psicobio.epm.br

Whole blood hypoxia-related gene expression reveals novel pathways to obstructive sleep apnea in humans

In this study, our goal was to identify the key genes that are associated with obstructive sleep apnea (OSA). Thirty-five volunteers underwent full in-lab polysomnography and, according to the sleep apnea hypopnea index (AHI), were classified into control, mild-to-moderate OSA and severe OSA groups. Severe OSA patients were assigned to participate in a continuous positive airway pressure (CPAP) protocol for 6 months. Blood was collected and the expression of 84 genes analyzed using the RT(2) Profiler™ PCR array. Mild-to-moderate OSA patients demonstrated down-regulation of 2 genes associated with induction of apoptosis, while a total of 13 genes were identified in severe OSA patients. After controlling for body mass index, PRPF40A and PLOD3 gene expressions were strongly and independently associated with AHI scores. This research protocol highlights a number of molecular targets that might help the development of novel therapeutic strategies.

The use of portable monitoring for sleep apnea diagnosis in adults

Due to increasing demand for sleep services, there has been growing interest in ambulatory models of care for patients with obstructive sleep apnea (OSA). The implementation of alternative approaches to the current management by full polysomnography (PSG) in the sleep laboratory is necessary for diagnosing this syndrome due to the high cost of full-night PSG. A good alternative option for OSA diagnosis is portable monitoring (PM), which is known for its accuracy, ease of management and lower cost when compared with full PSG. PM has not been well validated for OSA diagnosis in patients with medical comorbidities or in elderly individuals and children. PM may be recommended as an alternative method to PSG for patients with high clinical risk for OSA. In the present review, we describe the use of PM for OSA diagnosis and evaluate the current progress, costs, limitations and applications of these devices in various groups of patients, particularly for patients with comorbid diseases.