OBJECTIVES: Chitotriosidase (CHIT) is a functional chitinase secreted by activated macrophages. Considering that sleep is an important physiological event that directly influences health and is related to immune system function, our aim is to verify whether the activity of CHIT is altered after paradoxical sleep deprivation (PSD) and to assess the extent to which recovery sleep could affect this biological process.
METHODS: We analyzed CHIT enzymatic activity of Swiss and C57BL/6 mice and Wistar rats submitted to PSD for 72 hours without sleep rebound and with 24 hours of free sleep following PSD.
RESULTS: We observed an increase in the activity of plasma CHIT in PSD Swiss mice when compared to the Control group (CT) (p < 0.05), C57BL/6 mice (p < 0.05) and Wistar rats (p < 0.05). After 24 hours of sleep, no differences were observed in rebound group (RG) compared to PSD Swiss mice (p > 0.05). Moreover, differences were significant among RG C57BL/6 mice (p < 0.05) and RG Wistar rats (p < 0.01) compared with their respective PSD groups.
CONCLUSIONS: Our data suggest that CHIT is a relevant marker of macrophage activation, not only for infections and diseases but also after 72h of PSD in mice and rats.
Keywords: immune system, mice, rats, sleep deprivation.
OBJECTIVES: Yerba mate (Ilex paraguariensis, Ip) consumed as an infusion (tea), is a traditional and widespread beverage from South America. Even though a waking-promoting effect of Ip is suggested in folklore and traditions, there are no studies that have analyzed the effect of Ip on wakefulness and sleep. Hence, the aim of the present report is to study, for the first time, the effects of Ip on wakefulness and sleep.
METHODS: Adult cats were prepared for polysomnographic recordings in semi-restricted conditions for 4 hours/day. The animals were recorded after oral Ip (10 and 30%) administrations in control and sleep deprived conditions. We analyzed different parameters of wakefulness and sleep, and performed a quantitative analysis of the electroencephalogram (EEG).
RESULTS: Ip infusion produced a dose-dependent increase in wakefulness and a decrease in non-REM sleep (NREM). Comparing to control infusion, during a sleep deprivation protocol a smaller number of stimuli were required to keep the animal awake under the effect of Ip. Furthermore, the sleep rebound that followed the sleep deprivation protocol, was significantly reduced. The waking-promoting effect of Ip infusion administered daily, was maintained for seven consecutive days, and the abrupt cessation of Ip administration did not result in an increase of sleep. EEG quantitative analysis suggests that Ip produces more alert or attentive wakefulness and shallow sleep episodes.
CONCLUSIONS: We demonstrated that Ip is a natural product with activating effects. This preclinical study may be the basis for new natural treatments to reduce sleepiness.
Keywords: caffeine, medicinal plants, natural products, sleep stages, wakefulness.
OBJECTIVES: The purposes of this study were to reveal how far the core body temperature rhythm phase advances and the corresponding changes in sleep structure. The extremities of core body temperature rhythm shifts and nocturnal sleep structure changes were examined during 6 days of 6-hour phase advance treatment using bright light and melatonin under the natural light-dark cycle.
METHODS: Six healthy males received phase advance treatments with 1 hour bright light exposure after waking, oral melatonin (1.0 mg) administered in the early evening, and advancement of environmental routines intended to advance the onset of the sleep period 1 hour per day. Core body temperature was recorded continuously for 8 days comprising adaptation, baseline, and 6 treatment days. Nighttime sleep quality was evaluated by polysomnography (PSG) on adaptation, baseline, night 3, and night 6.
RESULTS: The core body temperature nadir in each day compared with baseline advanced significantly (p < 0.05). The mean nadir had advanced approximately 4.5 hours from baseline by day 6. The only significant change found in sleep structure was REM sleep duration, which was significantly decreased in day 6 compared with baseline (p < 0.05). Significant negative correlations existed between nadir phase advances and %REM in baseline, day 3, and day 6 recordings.
DISCUSSION: Thus, phase advances greater than 4 hours were possible under natural light-dark condition, although a phase shift of 1 hour per day may be too rapid to maintain normal sleep structure.
Keywords: body temperature, circadian rhythm, jet lag syndrome, polysomnography.
OBJECTIVES: Besides being an administrative effort directed to decrease electric energy expenditure in industrialized countries, daylight saving-time (DST) interacts with Human organism and may represent a potential temporal challenge. Therefore, the aim of the present work is to analyze the interaction between the transitions to and from DST on internal temporal organization.
METHODS: Five subjects were submitted to concomitant assessment of wrist temperature and actigraphy for two periods of 20 days comprising the transitions to and from DST. Data were extracted and amplitude, acrophase and mesor were estimated by Cosinor method.
RESULTS: Mesor and amplitude of the studied rhythms remained unchanged during both transitions. Acrophases of wrist temperature and rest-activity rhythms advanced in distinct magnitudes in the transition to DST. Leaving DST to local time, however, only wrist temperature showed a marginally phase delay. Discrepancies regarding phase shifts changed the phase relationship between the studied rhythms, resulting in an increase of 67 minutes in phase angle in the transition to DST and a decrease of 115 minutes in the transition from DST to regular local time.
CONCLUSIONS: DST evokes acute changes in phase relationship between wrist temperature and rest-activity rhythms, representing a significant temporal challenge, thus explaining the interaction among DST transition, sleep physiology and incidence of traffic and workplace accidents.
Keywords: body temperature, chronobiology discipline, circadian rhythm, synchronization.
OBJECTIVES: The aims of the present study were to verify whether sleep pattern could influence the food intake profile as well as to examine the impact of body composition on sleep pattern in obese adolescents.
METHODS: This is a cross-sectional study comprised of 55 post-puberty adolescents (15 to 19 years of age) with body mass indices greater than the 95th percentile. The anthropometric variables analysed were waist circumference, body weight, height, body mass index and body composition. Nutritional data were obtained throughout a 3-day dietary record, and sleep parameters were recorded using a 7-day sleep diary. Statistical analyses were performed using multiple linear regressions with significance set at p < 0.05, and the effect size (r) was calculated for both models.
RESULTS: The models models of multiple linear regression analyses adjusted by gender revealed that body fat mass (kg) was an independent predictor of greater influence of sleep latency and the total sleep time on lipid intake. It was observed that a reduction in sleep time might contribute to the development and maintenance of obesity through an increase in fat intake. Furthermore, the data suggest that the total fat mass might be associated with higher sleep latency, contributing with a reduction in sleep duration, confirmed by an expressive effect size. CONCLUSION: The results indicate that an association between reduced sleep duration and irregular eating habits can promote a vicious cycle difficult obesity control in adolescents.
Keywords: adolescent, body fat distribution, lipids, obesity, sleep, sleep disorders.
REM behavior disorder (RBD) is a parasomnia characterized by muscle tonus during REM sleep and presence of vigorous movements which can be potentially harmful. RDB is mostly prevalent in men between 40 and 70 years and it is usually associated with neurodegerative disease. Obstructive Sleep Apnea (OSA) is a common disorder in the general population and may present multiple clinical manifestations that include disrupted sleep. Arousals with vigorous movements may be present in patients with OSA and may express a clinical manifestation known as pseudo RBD. Using the keywords “Obstructive sleep apnea” and “REM behavior disorder” in the main data bases we found a total of 99 articles, but 94 articles were excluded because they did not specifically approached the relationship between the 2 diseases. Therefore, 5 articles were initially evaluated and we included 2 more relevant studies that were quoted by the initially selected articles. The articles reviewed consisted mainly of case reports or small case series. Pseudo RDB is usually associated with severe OSA and severe oxyhemoglobyn desaturations. The small number of reports may indicate a low awareness of this condition.
Keywords: electromiography, obstructive sleep apnea, polysomnography, REM behavior disorder.
Medical practice of sleep medicine requires an extensive pharmacological knowledge, especially when you need to make decisions about the drug scheme already adopted by a given patient. The care of patients with multiple diseases and using of multiple drugs has become common. The great challenge facing the physician is to what extent one or more drugs may be contributing to the complaint of sleepiness or insomnia. Any drug with activity in the central nervous system has the potential to affect sleep-wake cycle. The pharmacokinetic drug knowledge’s will be useful in determining the likelihood of adverse effects on sleep-wake functioning. In this article we describe the potential sedative or in generating insomnia by drugs used in the major chronic diseases in the population.
Keywords: conscious sedation, drugs, hypersomnia, sleep, sleep disorders.