ABSTRACT
Objectives@#Light at night (LAN) can suppress melatonin secretion and thus disturb normal sleep. The aim of this study was to investigate how the illumination of a smartphone at bedtime affects the circadian rhythm and sleep in patients with insomnia. @*Methods@#We recruited two middle-aged patients (one day worker and one shift worker) with insomnia. They used a smartphone more than 12 hours a day, particularly at bedtime. This was a crossover design study, and each patient spent a night at the light control unit twice at a one-week interval, with or without smartphone use. Patients were instructed to look at a smartphone (5–10 lux) under 150 lux of ceiling illumination from 18:00 until lights-off. During the night, without a smartphone, they read a book or newspaper. Saliva was collected every 30 minutes and analyzed for melatonin. Sleep was monitored by polysomnography. @*Results@#The day worker showed a delayed dim light melatonin onset time (DLMO) (21:30 vs. 22:00) and a 38.7% decrease in melatonin levels with smartphone use. For the shift worker, both melatonin and cortisol showed abnormal patterns, and thus DLMO was not determined in either condition. In the day worker, shorter rapid eye movement (REM) latency and increased REM were observed with smartphone use. @*Conclusions@#This study demonstrates that the use of smartphones at bedtime acutely suppresses melatonin secretion and delays the sleep-wake cycle. However, the effect of LAN on melatonin secretion was not apparent in the shift worker with already misaligned circadian rhythm.
ABSTRACT
Objectives@#Light at night (LAN) can suppress melatonin secretion and thus disturb normal sleep. The aim of this study was to investigate how the illumination of a smartphone at bedtime affects the circadian rhythm and sleep in patients with insomnia. @*Methods@#We recruited two middle-aged patients (one day worker and one shift worker) with insomnia. They used a smartphone more than 12 hours a day, particularly at bedtime. This was a crossover design study, and each patient spent a night at the light control unit twice at a one-week interval, with or without smartphone use. Patients were instructed to look at a smartphone (5–10 lux) under 150 lux of ceiling illumination from 18:00 until lights-off. During the night, without a smartphone, they read a book or newspaper. Saliva was collected every 30 minutes and analyzed for melatonin. Sleep was monitored by polysomnography. @*Results@#The day worker showed a delayed dim light melatonin onset time (DLMO) (21:30 vs. 22:00) and a 38.7% decrease in melatonin levels with smartphone use. For the shift worker, both melatonin and cortisol showed abnormal patterns, and thus DLMO was not determined in either condition. In the day worker, shorter rapid eye movement (REM) latency and increased REM were observed with smartphone use. @*Conclusions@#This study demonstrates that the use of smartphones at bedtime acutely suppresses melatonin secretion and delays the sleep-wake cycle. However, the effect of LAN on melatonin secretion was not apparent in the shift worker with already misaligned circadian rhythm.
ABSTRACT
Objectives@#Sleep issues are more prevalent in healthcare workers compared to workers in other industries. This study investigated sleep-wake pattern, sleep quality, and daytime status in hospital workers using a Galaxy Watch3 (GW3), a wrist-worn device that uses an accelerometer and heart rate sensor to distinguish sleep and wakefulness. @*Methods@#Multiple sleep parameters including total sleep time (TST) were obtained using a GW3. The Epworth sleepiness scale (ESS), insomnia severity index (ISI), Pittsburgh sleep quality index (PSQI), and bedtime procrastination scale (BPS) were used to assess participants’ status. @*Results@#A total of 70 daytime hospital workers (male, 45.7%; mean age, 35.66±7.79 yr) participated in the monitoring of their sleep-wake patterns for 30 consecutive days. Participants had a mean ESS of 8.14±3.62, ISI of 6.13±3.83, and PSQI of 4.86±2.14. The mean TST was 5.75±0.74 hr (range: 3.42–6.88) during workdays and 5.92±0.92 hr (range: 2.87–8.25) during free days. Chronotype (mid-sleep on freedays corrected for sleep debt accumulated over the work week) was 3.60±1.03 clock hr (range: 1.84–6.69). BPS was negatively correlated with age (rho=-0.27, p=0.022), TST of workdays (rho=-0.53, p<0.001), and TST of free days (rho=-0.43, p<0.001). A higher BPS was associated with larger social jetlag (rho=0.28, p=0.018) and later chronotype (rho=0.41, p<0.001). @*Conclusions@#In this study, 91.5% of daytime hospital workers suffered from chronic sleep insufficiency (<7 hr during both workdays and free days) although their daytime sleepiness or subjective sleep were not poor. Individuals with a later chronotype had poorer sleep quality and worse sleep procrastination behavior.
ABSTRACT
Objectives@#To investigate the etiologies of sleep disorders according to sex. @*Methods@#We enrolled 1,270 patients who complained of insomnia (n=328) or sleep apnea (n=942) for more than 6 months and classified them into primary insomnia (PI, n=120), comorbid obstructive sleep apnea with insomnia (COMISA, n=146), and obstructive sleep apnea (OSA, n=884) groups based on their polysomnography (PSG) findings, demographics, sleep-related symptoms, and questionnaire results (Insomnia Severity Index and Epworth Sleepiness Scale). @*Results@#The highest prevalence of females was observed in PI (71.7%), and the lowest in the OSA group (15.6%). Males were more prevalent than females in the COMISA group (58.2% vs. 41.8%). Regarding the etiology of insomnia, half of the male patients with complaints of insomnia had OSA, while only one-third of the females had OSA. Thirteen percent of female who complained of OSA-related symptoms were diagnosed as normal. There were few differences in PSG data between female and male patients in the PI and COMISA groups. Females with OSA showed longer total sleep time than males with OSA in PSG. The self-reported questionnaire responses of patients in the COMISA and PI groups were similar, and PSG data of patients in the COMISA and OSA groups were comparable regardless of sex. @*Conclusions@#Females and males have different sleep perceptions and sleep-related complaints. Thus, PSG must be carried out to clarify the etiology of sleep disorders and ensure appropriate treatment is provided.
ABSTRACT
Objectives@#To investigate the etiologies of sleep disorders according to sex. @*Methods@#We enrolled 1,270 patients who complained of insomnia (n=328) or sleep apnea (n=942) for more than 6 months and classified them into primary insomnia (PI, n=120), comorbid obstructive sleep apnea with insomnia (COMISA, n=146), and obstructive sleep apnea (OSA, n=884) groups based on their polysomnography (PSG) findings, demographics, sleep-related symptoms, and questionnaire results (Insomnia Severity Index and Epworth Sleepiness Scale). @*Results@#The highest prevalence of females was observed in PI (71.7%), and the lowest in the OSA group (15.6%). Males were more prevalent than females in the COMISA group (58.2% vs. 41.8%). Regarding the etiology of insomnia, half of the male patients with complaints of insomnia had OSA, while only one-third of the females had OSA. Thirteen percent of female who complained of OSA-related symptoms were diagnosed as normal. There were few differences in PSG data between female and male patients in the PI and COMISA groups. Females with OSA showed longer total sleep time than males with OSA in PSG. The self-reported questionnaire responses of patients in the COMISA and PI groups were similar, and PSG data of patients in the COMISA and OSA groups were comparable regardless of sex. @*Conclusions@#Females and males have different sleep perceptions and sleep-related complaints. Thus, PSG must be carried out to clarify the etiology of sleep disorders and ensure appropriate treatment is provided.
ABSTRACT
A 63-year-old female complained of transient dysarthria. MRA was conducted to evaluate this symptom, revealing distal internal carotid artery occlusion with collateral vessel development, suggesting Moyamoya disease, which had not been detected in MRA performed 5 years previously. Vascular risk factors and laboratory findings suggested no cardiac or autoimmune diseases. The diameter of stenosis of the middle cerebral artery on high-resolution MRI was 2.11 mm, and genetic evaluation revealed mutation of the gene encoding ring finger protein 213 (RNF213). High-resolution MRI and gene studies are useful for distinguishing between Moyamoya disease and atherosclerosis.