The release of hormones and the metabolism of human body are controlled by the circadian rhythm related to sleep-wake cycle. Growth hormone, prolactin, thyroid stimulating hormone, cortisol, glucose, and insulin-secretion rates fluctuate according to the sleep-wake cycle. In addition, sleep is related to the appetite regulation and carbohydrate and other energy metabolism. Hypocretin (orexin), an excitatory neuropeptide, regulates waking and diet intake, and the poor sleep increases diet intake. The short sleep duration increases one's body mass index and impairs the function of the endocrine and metabolism, causing increases in the risk of glucose intolerance and diabetes. The poor sleep quality and sleep disorders have similar impact on the metabolic function. In short, the sleep loss and the poor quality of sleep have a detrimental effect on the endocrine and energy metabolism. The improvement of sleep quality by the future research and appropriate clinical treatment would contribute to the decrease of the metabolic diseases such as diabetes.
Appetite Regulation ; Body Mass Index ; Circadian Rhythm ; Diet ; Energy Metabolism ; Glucose ; Glucose Intolerance ; Growth Hormone ; Human Body ; Hydrocortisone ; Intracellular Signaling Peptides and Proteins ; Metabolic Diseases ; Neuropeptides ; Prolactin ; Sleep Wake Disorders ; Thyrotropin ; Orexins

Sleep changes substantially with age. There is a phase advance in the circadian sleep cycle and increased waking after sleep onset. The elderly people wake more frequently during the night and experience fragmented sleep and excessive daytime sleepiness. The prevalence of sleep disorders increases with age, and the composition of sleep disorders in the elderly differs from that in the young. The most frequently encountered sleep disorders are psychophysiologic insomnia, sleep disturbance due to dementia, sleep-related respiratory disorder, restless legs syndrome and periodic limb movement disorder, and REM sleep behavior disorder. To treat the elderly sleep problem appropriately, it is important to know how sleep pattern changes as we age and to understand the cause of sleep-related symptoms. This article will review the sleep physiology and common sleep disorders in the elderly.
Aged* ; Dementia ; Humans ; Nocturnal Myoclonus Syndrome ; Physiology* ; Prevalence ; REM Sleep Behavior Disorder ; Restless Legs Syndrome ; Sleep Wake Disorders* ; Sleep Initiation and Maintenance Disorders

Excessive daytime sleepiness in childhood might be abnormal phenomenon and often related to the sleep disorders or insufficient sleep duration. The most common cause of excessive daytime sleepiness would be insufficient sleep. However, narcolepsy, idiopathic hypersomnia, circadian rhythm sleep disorders, medication, medical illness and other sleep disorders that could cause insomnia and poor quality of sleep also result in excessive daytime sleepiness. The misdiagnosed and untreated excessive daytime sleepiness in childhood can lead to serious developmental and educational problem.
Child ; Humans ; Hypersomnolence, Idiopathic ; Narcolepsy ; Sleep Wake Disorders ; Sleep Wake Disorders, Circadian Rhythm ; Sleep Initiation and Maintenance Disorders

Circadian rhythms have been observed to be disturbed in mood disorders, especially seasonal affective disorder (SAD). Clock related gene variants also have been suggested to be associated with seasonality (seasonal variations in mood and behavior). This study tested the potential association between a length polymorphism of Period3 gene and seasonal variations in mood and behavior. 297 Korean college students were genotyped for the Period3 polymorphism and were for evaluated the seasonal variation by Seasonal Pattern Assessment Questionnaire (SPAQ). The genotype frequencies were 0.76 for 4R/4R, 0.22 for 4R/5R and 0.013 for 5R/5R. The global seasonality score was not different among Period3 gene variants (4R/4R, 4R/5R and 5R/5R) except for 'sleep length' subscore. The 5R/5R genotype showed the higher 'sleep length' subscore than others (p=0.024). The comparison between seasonals (syndromal plus subsyndromal SAD determined by SPAQ) and non-seasonals did not show any significant difference in frequencies of genotypes. These findings suggest that there is a possibility that the investigated Period3 polymorphism may play a partial role in the susceptibility of seasonal variations in a Korean population.
Circadian Rhythm ; Genotype ; Humans ; Mood Disorders ; Surveys and Questionnaires ; Seasonal Affective Disorder ; Seasons*

OBJECTIVE: It has been reported that the sleep apnea syndrome in the asthmatic patients is prevalent, however, the systematic study in this field using polysomnography has rarely been performed. The aim of this study is to investigate the relationship between the apnea-hypopnea index (AHI) and the pulmonary function in asthmatic children. METHODS: This study enrolled 19 male and 12 female asthmatic children aged 6-13 years (average 8.2+/-1.7 years old). Complete overnight polysomnography and pulmonary function test were performed for the participants. RESULTS: Of the 31 asthmatic children, 21 (67.7%) met the diagnostic criteria of the pediatric sleep apnea and the average AHI was 1.7+/-1.5/h. The children with higher AHI showed poorer pulmonary function (FEV1/FVC ratio : p=0.002, FEV1%pred : p=0.047). CONCLUSION: These results suggest that the prevalence of the pediatric sleep apnea could be very high among the asthmatic children and the severity of the sleep apnea correlates with the pulmonary function. However, the case-control study to compare the AHI between the asthma and control groups is absolutely necessary because few normative data are available for the children.
Aged ; Asthma ; Case-Control Studies ; Child ; Female ; Humans ; Male ; Polysomnography ; Prevalence ; Respiratory Function Tests ; Sleep Apnea Syndromes

OBJECTIVES: The pathophysiology of restless legs syndrome (RLS) is not obvious, but many promising theories involve dopaminergic deficiency and genetic causes. The RLS is presumed to occur more frequently among schizophrenic patients who take antipsychotics, most of which blocks the dopamine receptors. This study aimed to investigate whether dopamine transporter gene (DAT1) 40 base pair (bp) variable number of tandem repeat (VNTR) polymorphism is associated with the antipsychotic-induced RLS in schizophrenia. METHODS: We determined the diagnosis of RLS among the 190 Korean schizophrenic patients by the diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG). Genotyping was performed for the 40bp VNTR in DAT1 gene using polymerase chain reaction. RESULTS: We separated the schizophrenic patients into 44 patients with RLS and 146 patients without RLS. The genotype and allele frequencies did not differ significantly between two groups. CONCLUSIONS: These results suggest that DAT1 gene 40bp VNTR is not associated with the antipsychotic-induced RLS in schizophrenia. To confirm these results, larger-scale association study is needed in the future.
Antipsychotic Agents ; Base Pairing ; Dopamine ; Dopamine Plasma Membrane Transport Proteins ; Gene Frequency ; Genotype ; Humans ; Receptors, Dopamine ; Restless Legs Syndrome ; Schizophrenia ; Tandem Repeat Sequences

OBJECTIVES: Angiotensin-converting enzyme (ACE) gene polymorphism has been reported to be associated with depression and therapeutic outcome in depression. The purpose of this study was to determine whether ACE gene polymorphism is associated with seasonal variation in mood and behavior in a young Korean college student sample. METHODS: 297 young Korean medical students were recruited in this study. All subjects were free of major medical and psychiatric problems. They were genotyped for the ACE gene polymorphism and evaluated the seasonal variation in mood and behavior by the Seasonality Pattern Assessment Questionnaire (SPAQ). RESULTS: Global Seasonality Score (GSS) of SPAQ between three genotypes were not different. However, comparison of the group that showed seasonality of mood and behavior during winter with the group that did not showed seasonality indicated significant difference in genotype distribution (chi-square=6.79, p=0.034). The D allele non-carrier (II genotype) frequency was significantly higher in winter seasonality group than non-seasonality group (chi-square=6.59, p=0.010; odds ratio [OR]=2.27, 95% confidence interval [CI] 1.20-4.28). CONCLUSION: These results suggest that the ACE gene polymorphism is related to winter-type seasonality in a Korean population.
Alleles ; Depression ; Genotype ; Humans ; Odds Ratio ; Surveys and Questionnaires ; Seasons* ; Students, Medical

OBJECTIVES: The aim of current study is to evaluate the relationship between sleep, suicide and serotonin using some scales and loudness dependence of auditory evoked potentials (LDAEP). METHODS: Total 65 patients who met the criteria for major depressive disorder were enrolled in current study. The patients were divided into two subgroups according to their insomnia and a history of suicide attempts. The auditory event-related potentials were measured to evaluate LDAEP before beginning antidepressants. RESULTS: The scores of total Beck Depression Inventory (BDI) and BDI item 9 (suicide) were higher in insomnia subgroup than non-insomnia subgroup (respectively, p=0.0033 and p=0.03). However, LDAEP did not differ each other. The subgroup with a history of suicide attempts had a higher score of BDI item 9 than the subgroup without a history of suicide attempts (p=0.00012). There was a tendency for the LDAEP to be higher in the subgroup with a history of suicide attempts (1.39+/-0.94 microV) than the subgroup without a history of suicide attempts (1.05+/-0.75 microV), although the difference was not statistically significant (p=0.078). CONCLUSION: Suicidality was related to insomnia. In addition, there was a tendency for serotonin activity to be lower in the subgroup with a history of suicide attempts. In future, more studies are needed.
Antidepressive Agents ; Depression ; Depressive Disorder, Major* ; Evoked Potentials ; Evoked Potentials, Auditory ; Humans ; Serotonin* ; Sleep Initiation and Maintenance Disorders* ; Suicide* ; Weights and Measures

OBJECTIVES: The aim of this study is to evaluate the polysomnographic characteristics and prescription status of restless legs syndrome (RLS) patients in naturalistic setting. METHODS: We reviewed medical record of the patients over 18 years olds who (i) satisfied the clinical RLS diagnostic criteria and (ii) had the polysomnography and got treatment related thereto. As a baseline, we evaluated the four diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG) and the International Restless Legs Scale (IRLS) of the subjects. Then the polysomnography and the suggested immobilization test (SIT) were conducted and, after one month of pharmacotherapy using dopamine agonist, the IRLS was evaluated again. RESULTS: A total of 211 subjects participated in this analysis and 94 (44.5%) of them were male and the other 117 (55.5%) were female and the average age of the 211 subjects was 46.9+/-14.2. Out of such 211 subjects, 136 subjects (64.5%) also had the obstructive sleep apnea (OSA), and 53 subjects (25.1%) also had the periodic limb movement disorder (PLMD). 185 subjects (87.7%) out of the 211 subjects had some other sleep disorders except RLS. The results of the polysomnography were as follows : 78.0% of sleep efficiency, 86.8 min of wake after sleep onset, and 3.4% of N3. More specifically, 12.4/h of the average apnea hypopnea index, 14.8/h of the periodic limb movement during sleep (PLMS), 41.2/h of the periodic limb movement during wake during SIT and 21.6/h of total arousal index during sleep. Out of the total subjects, 149 (70.6%) of them took the ropinirole and 47 (22.3%) of them took the pramipexole, and the average dosage of ropinirole was 0.9mg(dosage range 0.125-5 mg) while the average dosage of pramipexole was 0.5 mg (dosage range 0.125-4 mg). The dosage of the ropinirole showed a significant positive correlation with the age (r=0.25, p=0.002) and also with the IRLS (r=0.23, p=0.038). The IRLS at the baseline was 24.9 while the same was decreased down to 13.4 after one month. CONCLUSIONS: Analyzing the result of this study, a majority of clinical RLS subjects demonstrated comorbidity with some other sleep disorder such as the OSA or PLMD. 25.1% of the subjects showed a PLMD, which was less than in previous researches and the average PLMS was not very high as 14.8/h. The dosage of dopamine agonist taken was often a bit more than the amount recommended in Korea. A prospective research using a large scale controlled subjects will be necessary with respect to this topic.
Apnea ; Arousal ; Benzothiazoles ; Comorbidity ; Dopamine Agonists ; Extremities ; Female ; Humans ; Immobilization ; Indoles ; Isothiocyanates ; Korea ; Male ; Medical Records ; Nocturnal Myoclonus Syndrome ; Polysomnography ; Prescriptions ; Restless Legs Syndrome ; Sleep Apnea, Obstructive ; Sleep Wake Disorders

OBJECTIVES: The previous genome-wide association studies have revealed several candidate genes for restless legs syndrome (RLS). The PTPRD (protein tyrosine phosphatase receptor type delta) gene is one of the candidate genes for RLS. The occurrence of antipsychotic-related RLS could also be attributable to differences in genetic susceptibility. This study aimed to investigate whether PTPRD polymorphism is associated with antipsychotic-related RLS in schizophrenia. METHODS: We assessed symptoms of antipsychotic-induced RLS in 190 Korean schizophrenic patients and divided the subjects into two groups according to the International Restless Legs Syndrome Study Group diagnostic criteria : (i) subjects that met all of the criteria (n=44) and (ii) the remaining subjects who were not considered to be RLS patients (n=146). PTPRD rs462664 was genotyped by PCR in 190 individuals. The chi2-test was performed to compare differences between two groups. RESULTS: The frequencies of genotype (chi2=1.31, p=0.519) of the PTPRD rs462664 did not differ significantly between schizophrenic patients with and without RLS. The difference of allele frequencies (chi2=1.30, p=0.25) of the PTPRD rs462664 between the schizophrenic patients with and without RLS were not significant. CONCLUSION: These results suggest that PTPRD gene polymorphism does not play a major role in susceptibility to antipsychotic-related RLS in schizophrenia. This finding suggests that antipsychotic-induced RLS may have a different pathogenesis compared to primary RLS.
Gene Frequency ; Genetic Predisposition to Disease ; Genome-Wide Association Study ; Genotype ; Humans ; Polymerase Chain Reaction ; Restless Legs Syndrome* ; Schizophrenia* ; Tyrosine*