OBJECTIVE: To evaluate the effect of obesity on obstructive sleep apnea syndrome (OSAS) by age in relation to anthropometric measurements. METHODS: The medical records of 1,110 participants diagnosed with OSAS were analyzed according to age. All participants underwent nocturnal polysomnography and had their body mass index, waist circumference, neck circumference (NC), and waist-to-hip ratio measured. RESULTS: According to the multiple linear regression analysis model for the natural logarithm of the apnea-hypopnea index treating all four anthropometric measurements and gender as covariates, the final stepwise model accounted for an increasing percentage of the variability in the severity of OSAS as a function of age: 7.0, 9.1, 14.5, and 25.6% for those aged <30, 30–39, 40–49, and 50–59 yrs, respectively. It accounted for a decreased percentage among those 60–69 (20.3%) and 70 yrs or older (3.9%). The correlation between NC and the severity of OSAS linearly increased as a function of age for those aged 30–59 yrs, peaked among those in their 60s, and dramatically decreased thereafter. CONCLUSION: Middle-aged patients with OSAS were more likely to be obese, as measured by anthropometric measurements, than were younger or older OSAS patients. In particular, the predictive value of NC was significantly lower for younger and older OSAS patients.
Age Distribution ; Body Mass Index ; Body Weights and Measures ; Humans ; Linear Models ; Medical Records ; Neck ; Obesity* ; Polysomnography ; Sleep Apnea, Obstructive* ; Waist Circumference ; Waist-Hip Ratio

OBJECTIVE: In the present study, it was hypothesized that the sleep electroencephalogram (EEG) characteristics of young (<30 yrs) and elderly (>55 yrs) OSAS patients would differ. METHODS: We analyzed 76 sleep EEG recordings from OSAS patients (young group: n=40, mean age: 24.3±4.9 yrs; elderly group: n=36, mean age: 59.1±4.9 yrs), which were obtained during nocturnal polysomnography. The recordings were assessed via spectral analysis in the delta (0.5–4.5 Hz), theta (4.5–8 Hz), alpha (8–12 Hz), beta (12–32 Hz), slow sigma (11–13 Hz), and fast sigma (13–17 Hz) frequency bands. RESULTS: Apnea Hypopnea Index (AHI) and sleep efficiency (%) did not differ significantly between the two groups (19.8±14.4 vs. 25.9±16.0, p=0.085; 84.4±12.6 vs. 80.9±11.0, p=0.198, respectively). After adjusting for gender, the slow/fast sigma ratio was not significantly correlated with AHI in the elderly group (r=-0.047, p=0.790) but AHI was inversely correlated with the slow/fast sigma ratio in the young group (r=-0.423, p=0.007). A multiple linear regression analysis revealed that a higher AHI was related with a lower slow/fast sigma ratio in the young group (β=-0.392, p=0.028) but not the elderly. CONCLUSION: In the present study, sleep EEG activity differed between young and elderly OSAS patients. The slow/fast sigma ratio was associated with OSAS severity only in young patients, suggesting that young OSAS patients may have a distinctive brain plasticity compared with elderly patients.
Aged* ; Apnea ; Brain ; Electroencephalography* ; Humans ; Linear Models ; Plastics ; Polysomnography ; Sleep Apnea, Obstructive*

OBJECTIVES: To evaluate sleep characteristics and factors associated with sleep disturbance in schizophrenia patients with concurrent active psychotic symptoms and insomnia. METHODS: Schizophrenia patients with insomnia and active psychotic symptoms (n = 63) were recruited from communitybased mental rehabilitative facilities. Sleep scales such as the Korean version of the Insomnia Severity Index (ISI-K) and the Korean Version of the Pittsburgh Sleep Quality Index (PSQI-K) were evaluated and those with ISI-K >15 were included in the study. Psychotic, anxiety and depressive symptoms were rated with the Brief Psychotic Rating Scale (BPRS), the Korean Version of the Anxiety Sensitivity Index (K-ASI), and the Korean Version of the Beck Depression Inventory-I (K-BDI), respectively. Pearson correlation analyses were performed between the sociodemographic data, ISI-K and PSQI-K. Multiple linear regression analysis was conducted to investigate the factors which affected the ISI-K and PSQI-K. RESULTS: The mean ISI-K and PSQI-K scores were 18.1 ± 2.6 and 12.0 ± 2.2, respectively. Pearson correlation analysis showed a negative correlation between age of onset and ISI-K score and positive correlations between BRPS and PSQI-K scores and between K-ASI and both ISI-K and PSQI-K scores. Multiple regression analyses for both ISI-K and PSQI-K with K-ASI, age of onset, and BPRS as covariates revealed K-ASI as the only significant remaining factor. CONCLUSION: Our study suggests that anxiety symptoms are associated with insomnia symptoms in schizophrenia patients regardless of depressive or psychotic symptoms.
Age of Onset ; Anxiety ; Community Mental Health Services ; Depression ; Humans ; Linear Models ; Mental Health Services* ; Mental Health* ; Schizophrenia* ; Sleep Initiation and Maintenance Disorders* ; Weights and Measures

OBJECTIVE: The effect of transdermal nicotine patch on sleep physiology is not well established. The current study aimed to examine the influence of nicotine patch on homeostatic sleep propensity and autonomic nervous system. METHODS: We studied 16 non-smoking young healthy volunteers with nocturnal polysomnography in a double blind crossover design between sleep with and without nicotine patch. We compared the sleep variables, sleep EEG power spectra, and heart rate variability. RESULTS: The night with nicotine patch showed significant increase in sleep latency, wake after sleep onset, and stage 1 sleep; and decrease in total sleep time, sleep efficiency, and percentage of REM sleep. Also, spectral analysis of the sleep EEG in the night with nicotine patch revealed decreased slow wave activity in stage 2 and REM sleep and increased alpha activity in the first NREM-REM sleep cycle. Heart rate variability showed no differences between the 2 nights, but the low to high ratio (a parameter indicative of sympathetic nervous system activity) positively correlated with wake after sleep onset in night with nicotine patch. CONCLUSION: Transdermal nicotine patch significantly disrupts sleep continuity, sleep architecture, and homeostatic sleep propensity. The overactivation of the sympathetic nervous system may be responsible for these changes.
Adult* ; Autonomic Nervous System ; Cross-Over Studies ; Electroencephalography* ; Healthy Volunteers ; Heart Rate* ; Heart* ; Humans ; Male* ; Nicotine* ; Physiology ; Polysomnography ; Sleep, REM ; Spectrum Analysis ; Sympathetic Nervous System ; Tobacco Use Cessation Products*

OBJECTIVE: We investigated the prevalence of insomnia and its clinical characteristics in North Korean refugees. METHODS: North Korean refugees living in South Korea (48 males, 129 females; mean age 38.22+/-12.24 years) and South Koreans (112 males, 203 females; mean age 39.48+/-10.32 years) completed the following questionnaires: the Self-reported Questionnaire on Insomnia, Center for Epidemiological Studies-Depression Scale (CES-D), Trauma Exposure Check List for North Korean Refugees, and the Impact of Event Scale-Revised (IES-R). RESULTS: North Korean refugees had insomnia more often than South Koreans did (38.42% vs. 8.89%). Depression combined with insomnia was also more prevalent in North Korean refugees (28.25% vs. 3.17%). Compared with South Koreans with insomnia, North Korean refugees with insomnia showed higher CES-D scores. The North Korean refugees with insomnia had experienced a larger number of traumatic events, and had higher CES-D and IES-R scores compared to North Korean refugees without insomnia. Insomnia in North Korean refugees was also associated with the presence of significant depressive and post-traumatic stress disorder (PTSD) symptoms. CONCLUSION: Insomnia was common in North Korean refugees and was closely associated with depressive and PTSD symptoms. Our study suggests that complaints of insomnia may indicate more severe psychopathology, especially in refugees.
Depression* ; Female ; Humans ; Korea ; Male ; Prevalence ; Psychopathology ; Refugees* ; Sleep Initiation and Maintenance Disorders* ; Stress Disorders, Post-Traumatic

Over the last decade, physiologically based pharmacokinetics (PBPK) application has been extended significantly not only to predicting preclinical/human PK but also to evaluating the drug-drug interaction (DDI) liability at the drug discovery or development stage. Herein, we describe a case study to illustrate the use of PBPK approach in predicting human PK as well as DDI using in silico, in vivo and in vitro derived parameters. This case was composed of five steps such as: simulation, verification, understanding of parameter sensitivity, optimization of the parameter and final evaluation. Caffeine and ciprofloxacin were used as tool compounds to demonstrate the “fit for purpose” application of PBPK modeling and simulation for this study. Compared to caffeine, the PBPK modeling for ciprofloxacin was challenging due to several factors including solubility, permeability, clearance and tissue distribution etc. Therefore, intensive parameter sensitivity analysis (PSA) was conducted to optimize the PBPK model for ciprofloxacin. Overall, the increase in C(max) of caffeine by ciprofloxacin was not significant. However, the increase in AUC was observed and was proportional to the administered dose of ciprofloxacin. The predicted DDI and PK results were comparable to observed clinical data published in the literatures. This approach would be helpful in identifying potential key factors that could lead to significant impact on PBPK modeling and simulation for challenging compounds.
Area Under Curve ; Caffeine* ; Ciprofloxacin* ; Computer Simulation ; Drug Discovery ; Humans ; In Vitro Techniques ; Permeability ; Pharmacokinetics* ; Solubility ; Tissue Distribution

This study aimed to present the prognosis after minor acute ischemic stroke (AIS) or transient ischemic attack (TIA), using a definition of subsequent stroke in accordance with recent clinical trials. In total, 9,506 patients with minor AIS (National Institutes of Health Stroke Scale ≤ 5) or high-risk TIA (acute lesions or ≥ 50% cerebral artery steno-occlusion) admitted between November 2010 and October 2013 were included. The primary outcome was the composite of stroke (progression of initial event or a subsequent event) and all-cause mortality. The cumulative incidence of stroke or death was 11.2% at 1 month, 13.3% at 3 months and 16.7% at 1 year. Incidence rate of stroke or death in the first month was 12.5 per 100 person-months: highest in patients with large artery atherosclerosis (17.0). The risk of subsequent events shortly after a minor AIS or high-risk TIA was substantial, particularly in patients with large artery atherosclerosis.