Relationship of Limb Movements during Sleep with Nocturnal Sleep Parameters in the Community-Dwelling Elderly with Sleep Complaints / 신경정신의학

OBJECTIVES: The aim of this study was to examine the differences in subjective sleep quality and objective sleep parameters between groups with different severities of limb movements during sleep in elderly persons with sleep complaints. METHODS: We recruited adult subjects with sleep complaints from four areas in Gangwon-do. Nocturnal polysomnography studies were conducted for 159 subjects at Kangwon National University Hospital. A total of 72 subjects older than 60 years were finally selected, and we classified them into three groups according to the limb movement index (LMI) : 29 subjects with LMI below 15, 21 subjects with LMI between 15 and 44, and 22 subjects with LMI above 44. RESULTS: The proportion of existing restless legs syndrome (RLS) symptoms differed between the three groups, but was not statistically significant (p=0.051). No difference in nocturnal sleep parameters was observed between the three groups. In the total group, the limb movement arousal index showed positive correlation with respiratory arousal index (r=0.252, p<0.05). CONCLUSION: In elderly persons with sleep complaints, a greater LMI severity was associated with a tendency of higher comorbidity of RLS. Frequent arousals due to limb movements were not associated with a greater severity of limb movements during sleep severity, but with increased arousals due to respiratory events.

Sleep Wake Patterns and Nocturnal Sleep Parameters in the Morning and Evening Types / 신경정신의학

OBJECTIVES: The aim of our study was to compare sleep wake patterns and nocturnal sleep parameters between the morning type (MT) and evening type (ET). METHODS: The Morningness-Eveningness Questionnaire, Pittsburgh Sleep Quality Index (PSQI), and Korean version of the Epworth Sleepiness Scale (KESS) were administered to subjects recruited among visitors to the Chuncheon National Museum from 2010 to 2011. Actigraphy data (Actiwatch-2, Philips-Respironics Co.) were collected from eight MT (Age 38.0+/-3.8, M : F=2 : 6), 12 neither type (NT) (Age 34.2+/-5.1, M : F=2 : 10), and nine ET (Age 30.3+/-6.8, M : F=2 : 7) subjects. RESULTS: Scores for PSQI and KESS did not differ significantly among the MT, NT, and ET groups. No differences in time in bed, total sleep time, sleep efficiency, wake after sleep onset, sleep latency, and fragmentation index were observed among the three groups. In the ET group, the mean wake time on free days was significantly later, and the mean sleep duration on free days was significantly longer, compared with those of the MT group (p<0.01). CONCLUSION: No differences in sleep quality, daytime sleepiness, and nocturnal sleep parameters were observed among the MT, NT, and ET groups. Compared to MT subjects, ET subjects showed later wake time and longer sleep duration on free days.

Relationship of Sleep Parameters with Neurocognitive Function in the Elderly with Excessive Daytime Sleepiness (EDS) / 신경정신의학

OBJECTIVES: Excessive daytime sleepiness (EDS) in the elderly is related to cognitive dysfunction. We aimed to analyze the difference in the neurocognitive function between the elderly groups with and without EDS and examine the correlation between sleep parameters and the neurocognitive function in the elderly with EDS. METHODS: Thirty seven subjects who visited Kangwon National University Hospital were recruited. We excluded those who had abnormalities in laboratory examination or chronic systemic diseases. For each subject, a neuropsychological battery in the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K) Assessment Packet was applied. Nocturnal polysomnographies were conducted in 16 subjects with EDS. RESULTS: There were no significant differences in the neurocognitive function between EDS positive and EDS negative groups. In the EDS positive group, the amount of stage 1 sleep negatively correlated with scores on Boston naming test, word list memory and Stroop interference, respectively (r=-0.611, -0.583, -0.611). Also, REM sleep amount positively cor-related with scores of word list recognition (r=0.568), and limb movement index negatively correlated with scores of word list memory (r=-0.523). CONCLUSION: The poor sleep quality was associated with impaired language, memory and executive functions. Also, increased limb movements were associated with the memory decline.

Characteristics of Sleep Disturbances Correlated with Clinical Parameters in Hemodialysis Patients with Chronic Renal Failure / 신경정신의학

OBJECTIVES: Sleep disturbances are very common in hemodialysis (HD) patients with chronic renal failure (CRF). This study aimed to examine the characteristics of sleep disturbances, and to illustrate the relationship of sleep parameters with clinical parameters reflecting metabolic dysfunction in HD patients with CRF. METHODS: The Epworth Sleepiness Scale (ESS) and Sleep Disorders Questionnaire (SDQ) were administered in 26 HD patients with CRF. For fifteen patients with the risk of sleep disorder, nocturnal polysomnographic study (NPSG) and blood sampling were done. RESULTS: Among 15 patients, 14 patients (93%) were diagnosed as sleep disorders, sleep breathing disorder or periodic limb movements in sleep. Uric acid (UA) was positively correlated with sleep efficiency (r=0.571), and negatively correlated with waking after sleep onset, the amount of stage 1 sleep, and respiratory disturbance index (r=-0.515, -0.564, -0.646). Interleukin-6 was positively correlated with obstructive apnea index (r=0.661). CONCLUSION: In our study, the difficulty in maintaining sleep was found in HD patients with CRF. It also showed that increased UA was associated with improved sleep maintenance and decreased breathing disturbance during sleep. This might be related with antioxidant effect of UA in CRF. Further studies on total CRF patients including those without the risk of sleep disorder are necessary.