OBJECTIVES: An association, responsible for affecting circadian rhythms and sleep homeostasis, between PER3 gene variable number tandem repeat (VNTR) and sleep times has been described in humans. The aim of this study was to evaluate the association between clock genes VNTR and sleep duration, chronotype and melatonin secretion.
METHODS: A hundred forty-six students filled a questionnaire about their sleep habits to determine individual preferences. Salivary samples were also collected for DNA extraction. PER3 VNTR was genotyped using PCR.
RESULTS: Seventy subjects were PER34/4 (47.9%), 61 PER34/5 (41.8%) and 15 PER35/5 (10.3%). Mean sleep duration of PER35/5, intermediate chronotype students (8h) was higher than PER34/4, morningness chronotype (5:58h). On days-off, for evening-types, sleep outset was delayed (10:44h) when compared to morning-types (09:38h). Part of the students took part in a study about bright light intervention and its effects upon sleepiness. When exposed to bright light at 19:00h, the students’ sleepiness growth went as expected. But, when exposed at 21:00h, sleepiness slightly increased for the intermediates and decreased at 22:00h for the evening-type students. Analyzing PER3 and HIOMT genotypes a specific haplotype, associated to melatonin levels at 19:00h and after bright light exposure, at 19:20h, was detected.
CONCLUSION: With no social restrictions for sleep onset/outset, chronotypes express different sleep preferences, partly associated to PER3 VNTR genotype.
Keywords: chronobiology discipline, disorders of excessive somnolence, students.
OBJECTIVES: Rotating or night shifts elicit rapid changes in physiology which the body cannot quickly adapt. In addition, alterations in shift work influence social and familial aspects that ultimately impact the quality of life of these workers. The purpose of this study was to evaluate mood and sleep patterns as well the effects of physical exercise on the quality of life of train operators that work in shifts.
METHODS: This study was performed with 336 male train operators who worked on a rotating shift in a Brazilian company. The train operators underwent a polysomnography and subjective evaluations were made through the use of the following questionnaires: quality of life, work ability index, physical activity, anxiety, depression and sleepiness. Statistical analysis was performed using linear regressions, which the SF-36 scores were used as the dependent variable, and the sleep pattern variables (REM and sleep efficacy) and the subjective variables were used as independent variables. They were all adjusted for age and body mass index.
RESULTS: Alterations in the mood profile, low work capacity, sleepiness and altered of REM sleep had a negative impact while physical exercise contributed positively to the quality of life of Brazilian shift workers.
CONCLUSION: Shift workers with impaired mood profiles and sleep patterns have a negative impact on quality of life, in contrast to shift workers who engage in physical activity.
Keywords: physical activity, quality of life, shift work.
OBJECTIVES: Sleep Disordered Breathing (SDB) still remains unrecognized by the medical community, health-care providers and patients despite its high prevalence and association with other major health conditions. The aim of this study was to describe data about the SDB management, collected from 12 different Latin American sleep centers.
METHODS: Thirteen physicians from these sleep centers completed an electronic survey about SDB recognition, number of Sleep Physicians and Sleep Centers, as well as Sleep Medicine training in their respective countries.
RESULTS: Seventy-seven percent of the participants responded that Sleep Medicine is not recognized as a medical specialty in their country but despite that, 69% reported that there is specific and official training in Sleep Medicine and for Sleep Lab technicians in their countries. Sleep labs are officially registered only in Brazil and Colombia and only in Brazil sleep labs are certified by a scientific society. The 12 sleep centers studied summed up more than 45.500 sleep studies performed every year with an average of 60-80% positive studies for SDB. Most of the sleep centers (85%) perform Home Sleep Testing and use unattended Auto CPAP for home titrations. Eighty-five of the sleep centers have a CPAP clinic to support their patients with the PAP therapy set up.
CONCLUSION: Sleep Medicine is still not recognized as a medical specialty in most of Latin America and all participants agree that education should be number one priority to grow SDB awareness in Latin America.
Keywords: apnea, latin america, sleep, sleep disorders, sleep medicine specialty.
Together with the environment, genetic factors can significantly influence sleep and its architecture. Monozygotic twins have greater similarity in terms of latency and duration of sleep cycles than dizygotic twins, in addition to almost identical spectral patterns. These observations indicate a genetic contribution to sleep regulation and suggest that inter-individual variations in its parameters may be associated with genetic modulators. With the advent of techniques and molecular-genetic approaches, a number of genetic factors have been systematically identified that appear to contribute to the large variability observed in the normal sleep patterns of individuals and to a greater predisposition to the development of sleep disorders. This review aims to address the main scientific discoveries on the genetics of sleep in humans, presenting an overview of the current situation and future prospects in this constantly evolving area.
Keywords: genetics, genome, sleep.
The main concepts presented in this review are that sleep is not a function but a state diverse from the waking one. A lot of physiologic functions are carried out during sleep, cardiovascular, respiratory, endocrine, sensory, etc., although in a different way. This state occurs because there is a shifts in all/some cell assemblies-neuronal networks passing from a waking mode into a sleeping mode, perhaps organized by some unknown hub neurons. Since Bremer (1935) postulated a passive sleep theory i.e., the lack of sensory input would be the sleep cause, many active processes have being described. Moreover, since the nineteen sixties, several sensory approaches began to emphasize the role of the sensory input regarding sleep. We are proposing that at least a percentage of sleep generation is due to shifts in the sensory input to the brain determining changes in the cell assemblies-neuronal networks shift into a different mode the sleeping one. Many experimental data, from unitary recordings to every sensory system evoked potentials in human and animals as well as more recent magnetic evoked responses and brain imaging, support the notion of a sensory participation on sleep. The auditory, olfactory, vestibular and somesthetic system, developed introducing more sensory data which progressively shaped a brain that began to reach its completion, leading to a dynamic end: the genetically established sleep-waking cycle features. A proportion of “passive” effects must be associated with active functions for entering and maintaining normal sleep. Sleep generation, maintenance and every related event, are part of central processes that involve the whole brain.
Keywords: audio feedback, sensorimotor feedback, sensory feedback, sleep, visual feedback.
The present review article discusses the most important aspects of narcolepsy in children. The main objective of this review is to describe the clinical and laboratory characteristics of narcolepsy in patients within a targeted age range and to discuss hypotheses regarding the physiopathology of this disease. Excessive daytime sleepiness is reported by up to 20% of schoolchildren and adolescents. In 16% of these cases, narcolepsy begins before the age of 10 years, whereas 30% of narcoleptic patients exhibit its initial symptoms during childhood. A delayed diagnosis might lead to severe, negative future consequences for the affected patients. Human narcolepsy is a complex disease. The association of HLA-DQB1*0602 with low hypocretin levels indicates a genetic susceptibility with an associated immune component. Narcolepsy is characterized by excessive daytime sleepiness and cataplexy and might be associated with hypnagogic hallucinations, sleep paralysis, and sleep fragmentation. The diagnosis of narcolepsy depends on the clinical assessment and the performance of multiple sleep latency tests preceded by polysomnography. In children, the search for secondary causes of narcolepsy is important because approximately 25% of these patients are symptomatic. The treatment of narcolepsy in children is basically symptomatic, and most cases require behavioral and pharmacological approaches. New therapeutic modalities which impede progression of the disease at the onset of symptoms have also been investigated.
Keywords: adolescent, child, narcolepsy.
This study aimed to investigate the efficacy of acupuncture for the treatment of patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). The present work describes a clinical case study of a male patient who was clinically and polysomnographically diagnosed with mild OSAHS. There was a significant reduction in the apnea/hypopnea index (AHI) from 13.1 to 0.5 after 10 weeks of treatment and to 3.3 at 15 months after treatment. In addition, there was a reduction of respiratory events from 90 to 3 after 10 weeks and to 9 after 15 months. Acupuncture was effective in treating mild OSAHS; however, treatment for this disease should be initiated immediately after diagnosis to prevent progression.
Keywords: acupuncture, acupuncture points, sleep apnea syndrome.