Background and Objective: Sleep deprivation (SD) is caused by a host of reasons and has numerous consequences on cardiac system. In this study, we aimed to assess the preconditioning effects of acute SD on ischemia (IS)-induced ventricular arrhythmias in isolated rat hearts.
Materials and Methods: Male Wistar rats randomly were placed into the four groups: IS-group, acute SD group, control group for SD, and sympathectomy group (SYM). SD paradigm in SD was performed 24 hours before IS induction. In SYM groups, the animals were chemically sympathectomized 24 hours before SD. The rat hearts were isolated and perfused with Krebs buffer solution by Langendorff method and subjected to 30 minutes regional IS. Throughout the experiment, the hearts were allowed to beat spontaneously; thereafter, heart rate (HR) and ventricular arrhythmias were measured.
Results: No differences were found between the experimental groups for HR at baseline and IS period. As compared to IS group, SD animals showed less incidence of ventricular tachycardia and severity of arrhythmias (P < 0.050). Furthermore, significantly the number of ventricular ectopic beats episodes/min, bigeminy/min,trigeminy/min, and couple/min were less than IS group (P < 0.050). Moreover,  sympathectomy could reverse results to IS group level as compared to sleep deprived animals (P < 0.050).
Conclusion: It is concluded that induction of acute SD before IS could reduce ventricular arrhythmias, and chemical sympathectomy removed this cardioprotection.

Background and Objective: Narcolepsy is a chronic neurological disorder caused by loss of hypocretin (Hcrt) neurons. Both genetic and environmental factors play an important role for the development of narcolepsy. The mechanism of Hcrt loss in narcolepsy is elusive; however, an autoimmune mediated destruction of Hcrt neurons is suspected. The purpose of this study was to assess Th17 related cytokines: interleukin-6 (IL-6), IL-17, IL-23, and transforming growth factor beta (TGF-β) in the pathophysiology of narcolepsy and other types of excessive daytime sleepiness (EDS).
Materials and Methods: A total of 15 narcoleptic patients, 35 other patients with EDS and 48 age and sex matched healthy subjects were enrolled in this case-control study. Serum IL-6, IL-17, IL-23, and TGF-β levels were measured using sandwich enzyme-linked immunosorbent assay.
Results: There was no significant difference in IL-6 (P = 0.0618) and IL-23 (P = 0.7717) level among participants with narcolepsy, other patients with EDS and controls, whereas TGF-β was significantly decreased in the ones with narcolepsy and other EDS compared to healthy controls (P = 0.0039).
Conclusion: Decreased level of TGF-β in narcolepsy and other patients with EDS indicates a clue for the presence of dysregulation of inflammatory cascades in these patients. This study sheds a new insight on the pathophysiology of narcolepsy.

Background and Objective: Obstructive sleep apnea (OSA) syndrome is a kind of sleep-related disorder with complex features and may lead to daytime sleepiness. This study aimed to find the differences between smokers and non-smokers regarding the parameters of polysomnography.
Materials and Methods: This was a cross-sectional study conducted on consecutive patients referred to a sleep lab to perform polysomnography for sleep-related breathing disorders in Shahid Sadoughi University of Medical Sciences in 2014. For all participants, overnight polysomnography study was performed for at least 6 hours. Then, parameters of polysomnography were compared between smokers and non-smokers. Data were analyzed by SPSS using chi-square test, Student’s t-test, Mann–Whitney U-test, and logistic regression analysis.
Results: In total, 228 subjects were enrolled in the study (155 non-smokers). Obstructive apnea number and index,total apnea number, apnea-hypopnea index (AHI), baseline and average saturation by pulse oximeter, snore, and snore arousal were significantly different between smokers and non-smokers (P < 0.050). Severe OSA was the most commonly observed among smokers, but AHI was not significantly correlated with pack-years of smoking.
Conclusion: The results of this study showed that smokers suffer from severe OSA more frequent than nonsmokers; obstructive apnea is more common among smokers with higher AHI.

Background and Objective: Failure in diagnosis and treatment of sleep apnea in children lead to physical and mental growth retardation, cardiopulmonary, and/or behavioral disorders. This study was aimed to evaluate polysomnographic (PSG) and clinical findings of sleep apnea in children referred to a sleep clinic in Qazvin, Iran.
Materials and Methods: This cross-sectional study was conducted among 50 children and adolescents < 18 years old in Qazvin. All children referred to a pediatric sleep clinic during the years 2008-2009 were enrolled in this study, consecutively. These children were referred for suspected obstructive sleep apnea (OSA). BEARS and Children’s Sleep Habits Questionnaire were completed by parents. Subjects underwent overnight full PSG. Data were analyzed using descriptive statistics and chi-square test.
Results: A total of 50 subjects participated in this study. A mean age was 7.8 ± 5.2 years. 40 (80%) subjects were male. The most common cause for referral was snoring (18 patients, 36%). Daily hyperactivity and insomnia were reported in 20 (40%) and 16 (32%) subjects, respectively. 12 (24%) children had normal sleep pattern, 30 (60%) OSA and 8 (16%) other sleep disorders. No significant associations were seen between PSG results and body mass index or sex.
Conclusion: The majority of children referred to the sleep clinic had sleep apnea which indicates that many cases of the disease remain unknown. It is necessary to increase the knowledge of the public and medical staff about signs and symptoms of sleep breathing disorders to screen the patients and referral to sleep clinics.

Background and Objective: Morningness–eveningness (ME) refers to the individual differences in diurnal inclination, sleep-wake pattern for activity, and vigilance in the morning and evening. Quantitative and qualitative components of sleep can be measured through its quality. This study aimed to evaluate the association of ME chronotype with sleep quality and insomnia in students.
Materials and Methods: This cross-sectional study was performed from September 2013 to July 2014 among students. A total of 400 students of Islamic Azad University of Qom in the 1st to 4th year of education were recruited in this study. The students filled out questionnaires including demographic characteristics, Pittsburgh Sleep Quality Index (PSQI), and Insomnia Severity Index (ISI) and a self-assessment questionnaire for ME. Data analysis was performed using SPSS version 18 and simple and multiple linear regressions were used to quantify association between ME types with ISI and PSQI scores.
Results: A mean age of participants was 24.01 ± 5.80 years. A total of 164 (41%) of participants were male. Of these, 38.5% were in eveningness, 34.3% in intermediate and 27.3% were in moriningness chronotype groups. A significant association was observed between morningness chronotype and poor sleep quality (P < 0.001), but the relationship with insomnia was not statistically significant (P = 0.080).
Conclusion: This study showed morningness chronotypes are more likely to have poor sleep quality.

Background and Objective: Restless legs syndrome (RLS) is a sleep disorder with an association to sleep quality. We investigated the sleep quality in patients with RLS among health-care workers with or without shift work.
Materials and Methods: All female health-care workers (n = 540) in four educational hospitals were enrolled in this cross-sectional study. International RLS Study Group (IRLSSG) questionnaire, IRLSSG Rating Scale, Pittsburgh Sleep Quality Index (PSQI), and a data collection sheet including demographic characteristics and disorders related to secondary RLS were completed by study participants.
Results: The mean ± standard deviation (SD) age of the participants was 32.0 ± 6.8 years. The mean ± SD PSQI scores were 9.03 ± 3.29 and 7.30 ± 3.67 in RLS-positive and RLS-negative shift workers (P = 0.002), respectively. The mean ± SD PSQI scores were 7.76 ± 3.66 and 6.10 ± 3.15 in RLS-positive and RLS-negative non-shift workers (P = 0.005), respectively.
Conclusion: Health-care workers have poor sleep quality aggravated with both RLS and shift work. RLS-positive female patients are at increased risk of poor sleep quality in both shift workers and non-shift workers with the worst score of PSQI questionnaire in shift workers.

Background and Objective: Sleep disorders are common medical problems in most of the communities. However, medical students and general practitioners (GPs) do not have enough information about sleep disorders. The aim of this study was to assess the level of knowledge, attitude, and practice of GPs in the field of sleep disorders in Iran.
Materials and Methods: In this cross-sectional questionnaire-based study, all physicians working in the private sector of Qazvin were invited to participate in this study. A comprehensive questionnaire was used including questions about knowledge, attitude, and practice of GPs about sleep disorders. Univariate logistic regression was used for calculation of odds ratio and 95% confidence intervals for demographic factors.
Results: A total of 243 GPs participated including 123 (50.6%) females. A mean age of participants was 39.5 ± 8.2 years. The prevalence of sleep disorders among their patients was 25.2% and they believed that nearly 30% of cases of sleep disorders have been occurred following somatic disease. The average of knowledge, attitude, and practice in GPs was 63.8%, 49.4%, and 56.5%, respectively. There were lower levels of knowledge with increasing years after graduation.
Conclusion: Attitude and practice of the current study sample were unsatisfactory regarding managing sleep disorders. More specialized training about sleep disorders and teaching appropriate methods of the diagnosis and treatment of sleep disorders for GPs are needed.

Background and Objective: Obstructive sleep apnea (OSA) syndrome is a common sleep-related breathing disorder characterized by repeated episodes of the upper airway collapse during sleep. Loud snoring and daytime sleepiness are the main complaints; however, the condition may present with a variety of symptoms and signs.
Case Report: A 65-year-old woman was admitted to neurology ward with the diagnosis of intractable seizures. The physical examination revealed papilledema and huge obesity with body mass index of 41. Brain imaging was unremarkable. The pressure of cerebrospinal fluid was 33 cm H2O. As respiratory distress was observed, pulmonary evaluations were conducted. Finally, an overnight polysomnography confirmed the diagnosis of severe OSA. Positive airway pressure removed the symptoms.
Conclusion: This presentation suggests that severe OSA should be considered as a differential diagnosis for epilepsy and a probable cause of raised intracranial pressure, especially at the presence of obesity.