Keywords: Exercise; Sleep/physiology; Sleep, REM; Polysomnography; Physical fitness; Circadian rhythm; Body weight/physiology
OBJECTIVES: Evidence suggests that paradoxical sleep deprivation induces dopaminergic supersensitivity and noradrenergic subsensitivity. Previous studies have demonstrated that 96 hours of paradoxical sleep deprivation enhance cocaine-induced penile erection and ejaculation. The present study investigated the influence of the dopaminergic agonist apomorphine and noradrenergic antagonist propranolol in reverting genital reflexes potentiated by cocaine.
METHODS: Rats were exposed to 96 hours of paradoxical sleep deprivation and received acute and chronic intraperitoneally injections of apomorphine (120, 240 and 480 µg/kg) or propranolol (2, 4 and 8 mg/kg) before being challenged with cocaine (7 mg/kg). Acute or chronic apomorphine (240 and 480 µg/kg) administration reduced the proportion of animals that displayed erection.
RESULTS: acute propranolol administration induced a decrease in the proportion of animals displaying penile erection only at the lowest dose. Penile erection frequency decreased after acute and chronic propranolol treatment.
CONCLUSIONS: This study indicatesd that dopaminergic supersensitivity and noradrenergic subsensitivity have critical roles in the regulation of sexual reflexes.
Keywords: Sleep deprivation; Cocaine; Sexual behavior, animal; Ejaculation/drug effects; Penile erection/drug effects; Genitalia, male/drug effects; Dopamine/therapeutic use; Apomorphine/therapeutic use; Propranolol; Animals; Rats
OBJECTIVE: Total sleep or selective REM-sleep deprivation (SD) increases aggressiveness. Rats that display fighting when submitted to sleep-deprivation are those that manifest wild running (WR), a panic-like flight that precedes tonic-clonic seizures induced by intense acoustic stimulation (audiogenic epilepsy). The incidence of WR-sensitive rats in the colonies around the world may reach 20%, which makes important to know the other characteristics of these animals for both sleep and other kinds of experimental research. Based on the report of their reduced body weight, we investigated some glucose metabolism parameters.
METHODS: Adult male Wistar rats were submitted to high-intensity acoustic stimulation (112dB, 60s) and then classified as WR-sensitive or WR-resistant rats. Glycemia and insulinemia, measured by glucometer and radioimmunoassay, respectively, and body weight were analyzed during three months. At the end of this period, intraperitoneal glucose and insulin tolerance tests were performed, and hepatic fat and glycogen content were also determined.
RESULTS: WR-sensitive rats showed proportionally less gain of body mass compared to the resistant ones (p<0.05) in initial measurements, but this tendency did not sustain thereafter. Interestingly, fasting glycemia was significantly lower in the WR-sensitive group throughout the experiment, compared to WR-resistant rats. No significant differences between groups were found in insulinemia, peripheral glucose and insulin tolerance, and hepatic glycogen. However, WR-sensitive rats increased hepatic fat content significantly after a 12-hour fasting.
CONCLUSIONS: Slow weight gain, decreased fasting glycemia and hepatic steatosis suggest a possible accelerated energetic metabolism or low resistance to food deprivation, which could partially explain the reduced body weight of WR-sensitive rats.
Keywords: Running; Sleep deprivation/physiopathology; Sleep deprivation/metabolism; Acoustic stimulation; Aggression; Panic/physiology; Blood glucose/metabolism; Adipose tissue/metabolism; Body weight; Seizures/metabolism; Epilepsy, reflex/physiopathology; Energy m
OBJECTIVE: Rapid Eye Movement Sleep Deprivation (RSD) increases aggressiveness and is manifested in male rats as fighting episodes. The determination of the role played by such fights should constitute an important contribution toward assessing the adaptive function of this type of sleep. Nevertheless, female rats do not exhibit such behavior. Recent data indicate that RSD-induced fighting and wild-running flights are panic manifestations, thus advancing the hypothesis that female rats do not fight because their prevalent response in panic situations is flight.
METHODS: Therefore, 10 male and 12 female rats were acoustically kindled at 14 days of age, and their susceptibility to display wild-running was evaluated at 30, 60 and 90 days of age.
RESULTS: Six males and ten females produced respective totals of 12 and 30 wild-running episodes (chi-square test, p=0.0003), with mean (± standard error) of 0.60±0.21 and 1.41±0.24 episodes/rat. (ANOVA/MANOVA, p=0.0169).
CONCLUSION: The results validate the hypothesis and are concordant with the higher frequency of panic attacks observed in women as compared to men.
Keywords: Sleep, REM; Sleep deprivation/physiopathology; Aggression/physiology; Panic/physiology; Rats
OBJECTIVE: To compare clinical and polysomnographic profiles of patients with obstructive respiratory sleep disorder according to the type of recommended treatment.
METHODS: A retrospective study of 131 patients treated at the sleep disorders outpatient clinic of Faculdade de Medicina do ABC, between August 2003 and July 2008. The indication of treatment considered both clinical and polysomnographic criteria. The patients were divided into clinical and surgical treatment groups.
RESULTS: Of the 131 patients, 59.5% were male and 40.5% were female with an average age of 48.9 ± 13.2 years. Clinical treatment was recommended for approximately 71.8% of the patients, and surgical treatment was recommended for approximately 28.2% with a prevalence of continuous positive airway pressure (CPAP) (60.6%). In both groups, there was male prevalence, and the average age was between forty and fifty years with no statistical significant differences between the groups. In the group receiving clinical treatment, the majority of the patients had moderate and severe obstructive sleep apneas (OSA). No statistical differences were found between the two groups in terms of clinical and polysomnographic variables.
CONCLUSION: The majority of the patients were clinically treated with CPAP prevalence. However, almost one-third of the patients needed surgical intervention, with a high prevalence of anatomical abnormalities in this group. The type of recommended treatment was not influenced by clinical or polysomnographic parameters, which suggests that the presence of anatomical abnormalities in the upper respiratory tract or craniofacial region may be the main criterion for recommending surgical treatment.
Keywords: Sleep apnea, obstructive/surgery; Polysomnography; Positive-pressure respiration; Pharynx/surgery; Continuous positive airway pressure
OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) has gained increased attention in recent years, mainly due to the increased number of diagnosed cases and OSAS's relationship with other diseases. About 90% of the patients with OSAS snore. The objective of this paper was to investigate the relationship between the Stanford classification and the apnea-hypopnea index in patients with OSAS.
METHODS: Two hundred six patients were included in a longitudinal cohort study. The patients were evaluated and classified according to the Mallampati score, Stanford classification and the severity of their OSAS, as measured by the apnea-hypopnea index (AHI) using polysomnography.
RESULTS: A total of 168 patients who underwent polysomnography in the sleep laboratory were included in the final study. In a cross-tabulation of the Stanford classification for snoring and the AHI, the relative risk (RR) was 3.06 (95%CI 1.47 and 6.33). Therefore, we can infer that a patient with loud and intense snoring has a greater chance of developing moderate to severe OSAS.
CONCLUSION: We concluded that there is a positive correlation between the intensity of snoring and OSAS severity.
Keywords: Snoring/classification; Sleep apnea syndromes/complications; Polysomnography/methods
OBJECTIVE: Few studies about sleep have been conducted in healthy older adults. The objective of this study was to describe behavioral and environmental factors that can provide a good quality of sleep in Brazilian healthy older adults.
METHODS: Healthy older adults without evidence of disease, not taking any medication and who were able to perform instrumental activities of the daily life were included in the study. They were submitted to full geriatric assessment and to The Pittsburgh Sleep Quality Index questionnaire. Forty patients (87%) had good sleep quality (PSQI < 5) and were selected to be studied. The following variables were collected: age, sex, education level, family income, employment status; subjective temperature sensation and ventilation conditions in the room; bed conditions; self-analysis of health status; number of awakenings during the night; daytime napping; television set in the sleep environment and types of nighttimes TV programming watched; subjective latency and sleep duration; regularity of sleep onset/waking times; nocturia and sexual frequency.
RESULTS: Half of the sample presented overweight or were obese. Sixty per cent (n=24) had a good family income. Self-analysis of health status showed that all patients ranked their health as good, very good or excellent. No subjects referred bad or very bad health conditions. Over 90% of the subjects reported good bed and room conditions. Three-quarters of the sample had at least one episode of waking during the night and 70% reported daytime napping few days per week or daily.
CONCLUSIONS: In conclusion, we found that adequate sleeping habits, as well as the absence of health disorders, apparently contribute to the results observed. Nocturia, naps and overweight did not affect sleep quality in healthy aged people.
Keywords: Sleep disorders/physiopathology; Sleep disorders/epidemiology; Aging/physiology; Attitude to health; Circadian rhythm; Sleep stages; Predictive value of tests; Questionnaires; Geriatric assessment; Middle aged; Brazil
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 SpO2min (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 pm and ended at 7:00 am, while the day shift was either from 7:00 am to 1:00 pm or from 1:00 pm to 7:00 pm. 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).
CONCLUSION: 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
The aim of this study was to show the efficacy of mandibular repositioning appliance (MRA) to treat severe obstructive sleep apnea (OSA) on a marked retrognathic patient that refused continuous positive airway pressure (CPAP) therapy. The apnea/hypopnea index (AHI) reduced from 38.5 to 12.0, despite marked retrognathia represented for the variable pog/N-perp = -15.0 mm. After 6 months and after 3 years of MRA usage, another polysomnogram (PSG) was carried out. The results showed an AHI=12.0 and 13.0, respectively, besides improvements in other physiologic variables. We concluded that MRA was effective in the treatment of severe OSA with a marked retrognathia. Sleep physicians should consider this therapy option when patients refuse CPAP and surgery approaches.
Keywords: Sleep apnea, obstructive/therapy; Orthodontic appliance design; Orthodontic appliances, functional; Mandibular advancement/instrumentation; Retrognathism
There is evidence that regular exercises promote a number of changes and physiological benefits, and can be considered a non-pharmacological intervention, which improves the sleep quality of people who really do not have any sleep disorders. Yet, few studies have assessed how exercise can benefit a specific population with sleep disturbance. The aim of this study was to examine the influence of an aerobic training (AT) program of variable intensity in a sample of volunteers who had periodic leg movement (PLM) and obstructive sleep apnea syndrome (OSAS). The 51 year-old volunteer, body mass index (BMI) 28.67 kg/m2, sedentary, presenting PLM (rate>53,5/hour) and OSAS (AHI index >12,8/hour) was submitted to aerobic training on a treadmill in the mornings 3 times a week, each session lasting 40 minutes, thus totaling 72 sessions. Prior to aerobic trainin., the volunteer took a maximum effort test (MET) so that prescription of safe aerobic training could be made. The first aerobic training was done at 60% of the VO2peak so that acute effects of exercise could be assessed. Sessions 2 up to 24 were performed at ventilation threshold 1 (VT1) and sessions 25 to 48 were performed between ventilation threshold 1 and ventilation threshold 2 while sessions 49 to 72 were done between VT1 and VT2, with predominance at VT2. Polysomnographic and maximum effort test tests were carried out every 6 months throughout the aerobic training period and one month after the 72 sessions (suspension of training). We demonstrate that aerobic training at the intensity of VT1 promoted a reduction in the rate of periodic leg movement in relation to baseline values (53.5/h to 38.6/h). After the increase in intensity of aerobic training and a shift to the VT1 and VT2 range with predominance in VT2, the rate of periodic leg movement rose (63.8/h), and after one month of training suspension this rate was still higher than that of its corresponding moment baseline value (72.8/h). The AHI also increased during heightened AT when AT was performed at the intensity of VT1 27.8/h during AT compared to baseline 12.8. Such rates approached baseline values at VT1 and VT2 with predominance at VT2 (13.0/h) only to increase once again after one month suspension of training. AT at loads compatible with VT1 promoted enough improvement in the rate of periodic leg movement to down-grade the condition from severe to moderate, but sleep apnea syndrome increased at that intensity of exercise climbing from mild to moderate. Such results suggest that the benefits credited to AT have distinct mechanisms of action in periodic leg movement and sleep apnea syndrome
Keywords: Sleep; Leg/physiopathology; Restless legs syndrome; Sleep disorders; Electromyography; Polysomnography; Sleep apnea, obstructive; Exercise therapy
In children, the sleep-wake cycle (SWC) is influenced by both social and biological factors. Recently, lifestyle changes have introduced a number of social factors that negatively impact sleeping patterns. This review characterizes the sleep-wake cycle and describes how social factors influence this cycle in children. Social factors such as bed-sharing and room-sharing, as well as media use, the family environment, and the school schedule, all impact a child's routine and affect health and well-being. While a routine can benefit a child's health, in some situations these factors can delay the beginning of sleep and negatively impact the sleep-wake cycle . When coupled with a school schedule that begins early in the morning, these factors can result in partial sleep deprivation, sleep disturbances, and irregular sleeping and waking times. These sleeping problems can result in low school performance, obesity, attention-deficit/hyperactivity disorder, and to be a predictor of insomnia in adolescents.
Keywords: Sleep-wake transition disorders; Socioeconomic factors; Child; Sleep deprivation; Sleep disorders
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