Psychometric assessment of subjective sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects

Smartphone viewing distance and sleep: an experimental study utilizing motion capture technology

There are studies reporting the negative impact of smartphone utilization on sleep. It is considered that reduction of melatonin secretion under the blue light exposure from smart-phone displays is one of the causes. The viewing distance may cause sleep disturbance, because the viewing distance determines the screen illuminance and/or asthenopia. However, to date, there has been no study closely investigating the impact of viewing distance on sleep; therefore, we sought to determine the relationship between smartphone viewing distance and subjective sleep status. Twenty-three nursing students (mean age ± standard deviation of 19.7±3.1 years) participated in the study. Subjective sleep status was assessed using the Pittsburgh Sleep Quality Index, morningness-eveningness questionnaire, and the Epworth sleepiness scale. We used the distance between the head and the hand while holding a smartphone to measure the viewing distance while using smartphones in sitting and lying positions. The distance was calculated using the three-dimensional coordinates obtained by a noncontact motion-sensing device. The viewing distance of smartphones in the sitting position ranged from 13.3 to 32.9 cm among participants. In the lying position, it ranged from 9.9 to 21.3cm. The viewing distance was longer in the sitting position than in the lying position (mean ± standard deviation: 20.3±4.7 vs 16.4±2.7, respectively, P<0.01). We found that the short viewing distance in the lying position had a positive correlation to a poorer sleep state (R²=0.27, P<0.05), lower sleep efficiency (R²=0.35, P<0.05), and longer sleep latency (R²=0.38, P<0.05). Moreover, smartphone viewing distances in lying position correlated negatively with subjective sleep status. Therefore, when recommending ideal smartphone use in lying position, one should take into account the viewing distances.

Investigation of the Relationship between Psychological Variables and Sleep Quality in Students of Medical Sciences

OBJECTIVES

Students of medical sciences are exposed to many emotional and mental problems. In light of the importance of sleep quality in learning and liveliness, this study was conducted to examine the relationship between psychological variables (stress, anxiety, and depression) and sleep quality of students.

DESIGN

This research is a cross-sectional analytical study, where all students studying at Fasa University of Medical Sciences in 2012-2013 year were selected. To examine the students' stress, anxiety, and depression values, the standardized 21-item DASS-21 was used, and to examine their sleep quality, Pittsburgh Sleep Quality Index (PSQI) was used.

RESULTS

The results of the study demonstrated that 73% of the students have moderate and severe stress, and 46.4% of them have PSQ scores ≥ 5. The students' mean sleep quality score was 4.65 ± 2.37, and their stress score was 8.09 ± 5.14. A statistically significant relationship was found between the students' stress levels and sleep quality (P < 0.001).

CONCLUSION

The high stress levels decrease students' sleep quality. High stress levels and also the significant relationship between stress value and decrease in students' sleep quality call for more attention to and care for students' emotional and mental issues and timely proper interference on the part of authorities.

Prevalence, symptomatic features, and factors associated with sleep disturbance/insomnia in Japanese patients with type-2 diabetes

PURPOSE

To clarify the prevalence and symptomatic characteristics of sleep disturbance/insomnia among type-2 diabetes mellitus (DM) Japanese patients.

METHODS

A cross-sectional survey of Japanese patients with the disorder was conducted. Participants consisted of 622 type-2 DM patients (mean 56.1±9.56 years) and 622 sex- and age-matched controls. Participants' scores in the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J), the Japanese version of the 12-item Center for Epidemiologic Studies Depression Scale (CES-D), the Medical Outcomes Study 8-item Short Form Health Survey (SF-8), and the glycated hemoglobin A1c (HbA1c) of type-2 DM patients were analyzed.

RESULTS

There were 253 poor sleepers (43.9%) in the type-2 DM group as a result of dichotomization with the PSQI-J cutoff total score of 5.5. The type-2 DM group recorded a higher mean PSQI-J total score (P<0.01) and manifested poorer sleep maintenance. Poor sleepers in both groups had lower mental component summary from SF-8 (MCS), physical component summary from SF-8 (PCS), and CES-D than good sleepers, and good sleepers in both groups had higher MCS, PCS, and CES-D than poor sleepers. Higher body mass index, presence of smoking habit, and living alone were significantly associated with sleep disturbance/insomnia symptoms, but HbA1c was not associated with sleep disturbance/insomnia in the type-2 DM group.

CONCLUSION

Individuals affected with type-2 DM are likely to experience sleep problems, characterized by disturbance in sleep maintenance. Sleep disturbance/insomnia symptoms in DM patients might considerably reduce health-related quality of life.

Reliability and Validity of the Pittsburgh Sleep Quality Index-Serbian Translation

The aim of this study was translating and exploring psychometric properties of Serbian Pittsburgh Sleep Quality Index (PSQI) in a sample of “good” and “bad” sleepers suffering from depression or obstructive sleep apnea (OSA). Formal translation and validation were performed on a sample of healthy controls, patients with untreated OSA, and with diagnosed major depressive disorder with evaluation of internal consistency, test–retest reliability, and construct and criterion validity. Controls and OSA subgroups were recruited from a larger sample of commercial drivers. One hundred and forty subjects, 84.3% male, 22–67 years old, were included. OSA subgroup had 59 subjects and depression subgroup had 40 subjects (22 females). Mean ± SD total PSQI was 3.5 ± 2.2 in controls, 4.9 ± 3.6 in OSA subjects, and 9.0 ± 4.9 in patients with depression. Cronbach’s α for total PSQI was 0.791. Subscale scores were significantly correlated to global PSQI in all subgroups. Intraclass correlation coefficient for global PSQI was 0.997 ( p < .001). Epworth Sleepiness Scale score was significantly correlated to global PSQI (ρ = 0.333, p < .001). Three subgroups differed significantly in total PSQI and PSQI ≥ 5, even after adjustments for age and gender ( p < .001). OSA patients had higher mean PSQI than controls but not significantly ( p = .272). PSQI-reported sleep latency did not correlate with PSG-measured sleep latency ( r = .130, p = .204). Total PSQI was significantly correlated to OSA severity (ρ = 0.261, p < .05). Serbian PSQI showed good internal consistency, test–retest reproducibility, and adequate construct and criterion validity, which supports further exploration of its use as a sleep quality screening tool in different target populations.

Does subjective sleep quality improve by a walking intervention? A real-world study in a Japanese workplace

OBJECTIVES

The purpose of this study was to evaluate the impact of a 4-week walking intervention on subjective sleep quality.

DESIGN

A prospective open-label study.

PARTICIPANTS

A total of 490 healthy workers were included in the study. The 490 participants were divided into a group of 214 participants with exercise habits (exercising group, EG) and a group of 276 participants without exercise habits (non-EG).

INTERVENTIONS

A walking intervention with a target of walking 10 000 steps daily for 4 weeks.

OUTCOME MEASURES

The Pittsburgh Sleep Quality Index (PSQI) questionnaire was administered twice (before the start and after the end of the study).

RESULTS

Overall, the walking intervention improved the participants' PSQI global score, sleep latency (minutes), sleep duration (hours), perceived sleep quality factor and daily disturbance factor. Among the EG participants, the walking intervention significantly improved the PSQI global score and perceived sleep quality. Among the non-EG participants, the walking intervention significantly improved the PSQI global score, sleep latency, sleep duration and perceived sleep quality.

CONCLUSIONS

A walking intervention might reduce the sleep latency and increase total sleep duration in working persons without exercise habits.

Sleep disturbances in Japanese patients with inflammatory bowel disease and their impact on disease flare

Background

Several studies have reported a significant association between sleep disturbance and inflammatory bowel disease (IBD). The aim of the present study is to compare the clinical characteristics and the health-related quality of life (HR-QOL) of Japanese IBD patients with or without sleep disturbances, and to investigate the risk factors for disease flare in these patients.

Methods

IBD patients were asked to complete a self-administered questionnaire including the Pittsburg sleep quality index and the 8-item short-form health survey. The information about disease flare within 1 year from enrollment in the study was analyzed with a multiple logistic regression model to identify risk factors for IBD flare-ups.

Results

The prevalence of sleep disturbances was 44.1 % (60 out of 136 IBD patients). Use of sleep medications was significantly higher in IBD patients with sleep disturbances whereas use of immuno modulators was significantly higher in IBD patients without sleep disturbances. The scores from all HR-QOL domains were significantly lower in patients with sleep disturbances than in patients without sleep disturbances. Fifty-one patients (37.5 %) had disease flare within 1 year from enrollment in the study and sleep disturbances were identified as a significant risk factor for disease flare (OR 3.09, 95 % CI 1.47–6.43).

Conclusions

Our results indicate that sleep disturbances are common in Japanese IBD patients and are associated with poorer HR-QOL. Since the presence of sleep disturbances is a significant risk factor for IBD flare-ups, we encourage physicians to perform a careful examination of sleep disturbances in IBD patients.

Schizophrenia: the role of sleep and circadian rhythms in regulating dopamine and psychosis

Schizophrenia has long been associated with abnormalities in circadian rhythms and sleep. Up until now, there have been no thorough reviews of the potential mechanisms behind the myriad of circadian and sleep abnormalities observed in schizophrenia and psychosis. We present evidence of sleep playing an important role in psychosis predominantly mediated by dopaminergic pathways. A synthesis of both human and animal experimental work suggests that the interplay between sleep and dopamine is important in the generation and maintenance of psychosis. In particular, both animal and human data point to sleep disruption increasing dopamine release and sensitivity. Furthermore, elevated dopamine levels disrupt sleep and circadian rhythms. The synthesis of knowledge suggests that circadian rhythms, dopamine dysregulation, and psychosis are intricately linked. This suggests that treatment of circadian disturbance may be a useful target in improving the lives and symptoms of patients with schizophrenia.

The Association between Sarcopenic Obesity and Depressive Symptoms in Older Japanese Adults

The effects of sarcopenic obesity, the co-existence of sarcopenia and obesity, on mood disorders have not been studies extensively. Our objective was to examine the association of depressive symptoms with sarcopenia and obesity status in older Japanese adults. We analyzed data from 1731 functionally-independent, community-dwelling Japanese adults aged 65 years or older (875 men, 856 women) randomly selected from the resident register of Kashiwa city, Chiba, Japan in 2012. Sarcopenia was defined based on appendicular skeletal muscle mass, grip strength and usual gait speed. Obesity was defined as the highest sex-specific quintile of the percentage body fat. Depressive symptoms were defined as a Geriatric Depression Scale 15-item score ≥ 6. Multiple logistic regression was employed to examine the association of depressive symptoms with four groups defined by the presence/absence of sarcopenia and obesity. The prevalence of depressive symptoms was 10.1% and the proportions of sarcopenia/obesity, sarcopenia/non-obesity, non-sarcopenia/obesity, non-sarcopenia/non-obesity were 3.7%, 13.6%, 16.9% and 65.8%, respectively. After adjustment for potential confounders, sarcopenia/obesity was positively associated with depressive symptoms compared with non-sarcopenia/non-obesity, whereas either sarcopenia or obesity alone was not associated with depressive symptoms. The association was particularly pronounced in those aged 65 to 74 years in age-stratified analysis. We conclude that our findings suggest a synergistic impact exerted by sarcopenic obesity on the risk of depressive symptoms, particularly in those aged 65 to 74 years.

Bodily pain, social support, depression symptoms and stroke history are independently associated with sleep disturbance among the elderly: a cross-sectional analysis of the Fujiwara-kyo study

OBJECTIVE

To investigate independent effects of various factors associated with sleep disturbance among community-dwelling elderly individuals.

METHODS

We analyzed data obtained from 3732 individuals aged ≥65 years who responded to a self-administered questionnaire and participated in a structured interview which assessed the Pittsburgh Sleep Quality Index (PSQI), subjective bodily pain, the Jichi Medical School Social Support Scale, the Geriatric Depression Scale (GDS-15), health status, and demographic characteristics. Sleep disturbance was defined as a global PSQI score >5.5, which was used as a dependent variable in multiple logistic regression analysis to determine adjusted odds ratios (ORs) and 95 % confidence intervals (CIs) of related factors.

RESULTS

We identified a significant increase in the adjusted ORs for female (OR 1.56, 95 % CI 1.34-1.83), age ≥80 years (1.31, 1.01-1.69), history of stroke (1.44, 1.08-1.92), and a GDS-15 score ≥6 as compared to 0-2 (2.29, 1.86-2.81), with regard to sleep disturbance. Participants with severe or very severe bodily pain had the highest adjusted OR (3.00, 2.15-4.19), and those with very mild bodily pain also had a relatively high OR (1.30, 1.06-1.60), relative to those without subjective bodily pain. In addition, compared with participants with strong social support from spouse or family, those with weak social support had significantly increased adjusted ORs (1.21, 1.01-1.44, 1.44, 1.23-1.70, respectively).

CONCLUSIONS

The present study indicates that sleeping disturbances among the elderly are closely associated with social support from a spouse and family. They are also associated with pain, even at stages in which subjective bodily pain is very mild.

Critical Transitions: A Mixed Methods Examination of Sleep from Inpatient Alcohol Rehabilitation Treatment to the Community

Aims

This prospective, repeated measures study utilized a convergent parallel mixed methods approach to assess sleep experiences among individuals who were alcohol-dependent undergoing inpatient detoxification and treatment at a clinical research facility across the transition periods associated with the rehabilitation process: the initial adjustment to becoming an inpatient and the transition from inpatient to outpatient status.

Methods

This study included individual semi-structured interviews and quantitative measures relating to psychological distress, sleep quality, daytime sleepiness, and sleep-related beliefs and behavior (n = 33; 66.7% male). Interviews were conducted and questionnaires were administered within one week of participants’ scheduled discharge date and again four to six weeks post-discharge when they returned for a follow-up visit (or via phone).

Results

Participants self-reported significant sleep disturbances at both study time points. Of those participants with valid data at both time points (n = 28), there were no significant changes in mean scores from pre- to post-discharge with the exception of self-efficacy for sleep (SE-S) being significantly higher post-discharge. Preliminary qualitative findings suggested differences between those with ongoing sleep disturbances, those whose sleep disturbances had resolved, and those with no sleep disturbances at either time point.

Conclusions

This analysis highlights individual variation in sleep throughout the process of inpatient treatment and transition to outpatient aftercare in individuals with alcohol dependence. Collecting quantitative and qualitative data concurrently and combining emerging themes from qualitative data with quantitative analyses allowed for a more thorough examination of this relatively novel area of research and provided information that can be utilized to inform future behavioral sleep interventions.

Impact of sleep on osteoporosis: sleep quality is associated with bone stiffness index

OBJECTIVE

The aim of the present study was to investigate the impact of sleep on osteoporosis.

METHODS

The study used a baseline examination of the Hiroshima Sleep and Healthcare study, which was a cross-sectional and cohort study that addressed the association of sleep habits with lifestyle-related diseases. A total of 1032 participants (25-85 years of age) who underwent health examinations were included. Sleep habits, including its timing (bed time), quantity (time in bed [TIB]), and quality, were assessed using the Pittsburgh Sleep Quality Index (PSQI). The bone stiffness index (SI), a marker of osteoporosis, was measured using quantitative ultrasound systems.

RESULTS

Bed time (r = 0.065, p <0.05), TIB (r = -0.064, p <0.05), and global PSQI score (r = -0.126, p <0.0001) significantly correlated with SI. Multiple regression analyses revealed that after adjusting for age, sex, body mass index, smoking, and alcohol intake, the global PSQI score (β = -0.053, p <0.05) was significantly associated with SI, whereas bed time or TIB was not. Among each component of PSQI, sleep disturbances (β = -0.084, p <0.005) were significantly associated with SI.

CONCLUSION

Poor sleep quality may be associated with osteoporosis. In particular, increased sleep disturbances may be a key factor in the association between poor sleep quality and osteoporosis.

A meta-analysis of diagnostic accuracy of three screening tools for insomnia

BACKGROUND

Insomnia is a highly prevalent health complaint in the modern societies; however, insomnia remains under-diagnosed and under-treated. Although screening tools, including the Insomnia Severity Index (ISI), Athens Insomnia Scale (AIS), and Pittsburg Sleep Quality Index (PSQI), are widely used for assessing the risk of insomnia, the diagnostic properties have yet to be summarized in a systematic manner.

OBJECTIVES

To estimate and to compare the diagnostic accuracy of the ISI, AIS, and PSQI for insomnia screening.

DATA SOURCES

We systematically searched EMBASE, PubMed, PsycINFO, CINAHL and Chinese Electronic Periodic Services for data from their inception to May 20, 2015.

DATA SELECTION

Original articles that had assessed the sensitivity and specificity of the ISI, AIS, or PSQI against a reference standard in adult participants (age>18) were included.

RESULTS

A total of 19 studies comprising 4693 participants were included. The pooled sensitivity for the ISI, AIS, and PSQI was 88% (95% confidence interval [CI]=0.79 to 0.93), 91% (0.87 to 0.93), and 94% (0.86 to 0.98), respectively. The pooled specificity was 85% (0.68 to 0.94), 87% (0.68 to 0.95), and 76% (0.64 to 0.85); and the pooled DORs was 41.93 (8.77 to 200.33), 67.7 (23.4 to 196.1), and 53 (15.5 to 186.2), respectively. The summary estimates did not differ significantly among the ISI, AIS and PSQI (all P>0.05).

CONCLUSIONS

The current evidence indicates that the ISI, AIS, and PSQI yield comparable diagnostic properties for insomnia screening.

Prevalence of Circadian Rhythm Sleep-Wake Disorders and Associated Factors in Euthymic Patients with Bipolar Disorder

Recent studies have suggested that there are certain pathophysiological relationships between bipolar disorder (BD) and circadian rhythm dysfunction. However, apparently no studies have clarified the prevalence of circadian rhythm sleep-wake disorders (CRSWD) in patients with BD. This study was set out to investigate the prevalence of CRSWD and associated factors in patients with BD. One hundred four euthymic BD outpatients participated in this study. The subjects were asked to answer questionnaires including demographic variables, clinical course of BD, and family history of psychiatric disorders and suicide. Severity of BD was assessed by the Montgomery-Åsberg Depression Rating Scale and Young Mania Rating Scale. CRSWD was diagnosed by clinical interview, together with sleep logs, according to the International Classification of Sleep Disorders, third edition (ICSD-3). Thirty-five subjects (32.4%) met the criteria for CRSWD. The age at the time of investigation and that at the onset of BD were both lower in the CRSWD group than in the non-CRSWD group. The rates of family history of psychiatric disorders and suicide in the CRSWD group were higher than those in the non-CRSWD group. Multiple logistic regression analysis revealed that the presence of CRSWD was significantly associated with younger onset age of BD and family history of suicide. The prevalence of CRSWD could be quite high in BD patients. Younger onset age of BD and family history of suicide were associated with presence of CRSWD in BD patients.

Perceived inadequate care and excessive overprotection during childhood are associated with greater risk of sleep disturbance in adulthood: the Hisayama Study

BACKGROUND

Sleep disturbance and poor sleep quality are major health problems worldwide. One potential risk factor for the development and maintenance of sleep disturbance is the parenting style experienced during childhood. However, its role in sleep disturbance in adulthood has not yet been estimated. This Japanese population study was done to clarify the relation between the parenting styles "care" and "overprotection" during childhood and sleep disturbance in adulthood.

METHODS

A total of 702 community-dwelling Japanese residents aged ≥ 40 years were assessed in 2011 for their perceptions of the parenting style of their parents by use of the Parental Bonding Instrument (PBI) and for sleep disturbance by use of the Pittsburgh Sleep Quality Index (PSQI). The odds ratio (OR) for sleep disturbance (a global PSQI score > 5) was calculated using a logistic regression model.

RESULTS

The prevalence of sleep disturbance was 29 %. After adjusting for sociodemographic, lifestyle, and physical factors in a comparison with the optimal parenting styles (high care and low overprotection), the ORs for sleep disturbance by men were significantly higher for low paternal care, by 2.49 times (95 % confidence interval [CI]: 1.21-5.09), and for high overprotection, by 2.40 times (95 % CI: 1.19-4.85), while the ORs were not significant for low maternal care and high overprotection. For women the only significant factor was high maternal overprotection, by 1.62 times (95 % CI: 1.05-2.52), while the ORs were not significant for low maternal care, low paternal care and high paternal overprotection. The association remained significant for high paternal overprotection for men after additionally controlling for depression.

CONCLUSIONS

This study suggests that parenting style, especially inadequate care and excessive overprotection during childhood, is related to sleep disturbance in adulthood and that the association is much more significant for parents of the same sex as the child.

Screening for minimal hepatic encephalopathy in patients with cirrhosis by cirrhosis-related symptoms and a history of overt hepatic encephalopathy

The diagnosis of minimal hepatic encephalopathy (MHE) is more difficult in comparison to the diagnosis of overt hepatic encephalopathy (OHE), as patients with MHE do not exhibit overt neurological deficits and must be diagnosed using specialized equipment. However, identifying MHE is critical for patients with cirrhosis, and a simple screening test is required. The present study aimed to evaluate the associations between MHE, clinical characteristics and questionnaire items regarding sleep disturbances and cirrhosis-related symptom score (CSS). A total of 91 patients who had cirrhosis without OHE were evaluated using various questionnaires [i.e., CSS, Epworth Sleepiness Scale, the Japanese version of the Pittsburgh Sleep Quality Index (PSQI) and the Japanese 36-item short-form health survey (SF-36)]. MHE was diagnosed using the neuropsychological test. MHE was associated with severe liver damage, which was indicated by liver damage markers and a history of OHE. In addition, MHE was associated with the CSS, PSQI and SF-36 results. The multivariate analyses revealed that a history of OHE was the factor that was the most strongly associated with MHE. Among patients without a history of OHE, MHE was most strongly associated with CSS, although it was also associated with severe liver damage and platelet counts. A prediction score (calculated using a history of OHE and CSS) provided an area under the receiver operating characteristic curve of 0.738 and a sensitivity of 0.671 for identifying MHE. In conclusion, a history of OHE and CSS may be useful for identifying MHE in patients with cirrhosis.

Excessive daytime sleepiness in adults with possible attention deficit/hyperactivity disorder (ADHD): a web-based cross-sectional study

OBJECTIVES

Arousal dysregulation has been speculated to be involved in the pathological mechanism of attention deficit/hyperactivity disorder (ADHD). However, there has been no epidemiological study assessing the real condition of excessive daytime sleepiness (EDS) in adults with ADHD. This study investigated the prevalence of EDS and the relationship between sleepiness and ADHD symptoms in adults with possible ADHD.

METHODS

An observational, cross-sectional, web-based study was performed. Participants were 9822 Japanese adults aged 20-69 years who completed an Internet-based questionnaire that assessed ADHD symptoms, autistic traits, depressive symptoms, chronotype, sleepiness, and sleep disturbances.

RESULTS

Participants with possible ADHD were more likely than non-ADHD participants to have an evening chronotype and experience depressive symptoms, sleepiness, and sleep disturbances. The rates of having moderate and severe sleepiness in the possible ADHD group were higher than those in the non-ADHD group. Hierarchical logistic regression analyses revealed that the presence of ADHD symptoms was independently associated with EDS even after adjusting for factors related to the presence of sleepiness. When examining inattention and hyperactivity scores among participants with possible ADHD, the inattention score was significantly higher in the severe EDS group compared with the moderate and non-EDS groups.

CONCLUSIONS

EDS was relatively common in adults with possible ADHD. ADHD symptoms, especially inattentiveness, were associated with the formation of EDS in this population.

Later sleep schedule and depressive symptoms are associated with usage of multiple kinds of hypnotics

OBJECTIVE

Usage of high doses of hypnotics possibly causes various adverse events. However, the risk factors of using multiple kinds of hypnotics have been inconclusive. To clarify this, we conducted a web-based cross-sectional questionnaire survey on the Japanese adult population.

METHODS

A cross-sectional Internet-linked survey was conducted on 10,016 individuals and 1030 participants (10.3%) having subjective insomnia proceeded to subsequent analyses. The analyzed subjects were categorized into non-users of hypnotics (n = 833; 80.9%), users of a single kind of hypnotic (n = 96; 9.3%), and users of multiple kinds of hypnotics (n = 101; 9.8%). The descriptive variables including demographic data, scores of Center for Epidemiological Studies Depression Scale (CES-D), Short Form-8 Health-Related Quality of Life [QOL (SF-8)], Pittsburgh Sleep Quality Index (PSQI), and other parameters were compared among the groups.

RESULTS

The users of multiple kinds of hypnotics had the highest mean score of CES-D, the lowest mental component summary of QOL (SF-8), and the latest sleep schedule among the three groups (p < 0.001). Logistic regression analyses revealed that sex (female: OR = 2.38; p < 0.001) and age (≥43 years old: OR = 2.61; p < 0.001) were independently associated with use of a single kind of hypnotic, while later sleep schedule (midpoint of sleep ≥5:30 a.m.: OR = 2.26; p < 0.001) and higher CES-D score (≥16 points: OR = 2.41; p < 0.001) were independently associated with use of multiple kinds of hypnotics.

CONCLUSIONS

Characteristics of users of multiple kinds of hypnotics were different from those of users of a single kind of hypnotic.

Substance use associated with short sleep duration in patients with schizophrenia or schizoaffective disorder

STUDY OBJECTIVES

To examine the association between substance use and short sleep duration in individuals with schizophrenia or schizoaffective disorder, depressive type (SADD).

DESIGN

Cross-sectional, retrospective study.

SETTING

Urban, suburban, and rural centers across the United States.

PARTICIPANTS

2,462 consented, adult individuals with schizophrenia or schizoaffective disorder, depressive type (SADD). Participants included inpatients in acute or chronic care settings as well as outpatients and residents in community dwellings.

MEASUREMENTS

Substance use was assessed with 10 questions adopted from well-validated measures (e.g., CAGE questionnaire) for alcohol, marijuana, and illicit drugs. Short sleep duration was defined as <6 hr of self-reported sleep per night.

RESULTS

Close to 100% of our sample used nicotine while 83% used substances other than nicotine. More importantly, there was a significant association between substance use and short sleep duration. Interestingly, this association was strongest among African-Americans with schizophrenia or SADD.

CONCLUSIONS

Because psychiatric medications often target chemical receptors involved with both sleep and substance use, understanding the association between short sleep duration and substance use in individuals with schizophrenia and SADD is important. Given that the majority of premature deaths in individuals with psychotic illness are due to medical conditions associated with modifiable risk factors, prospective studies designed to examine the effect of short sleep duration on behaviors like substance use should be undertaken. Finally, analyzing genetic and environmental data in a future study might help illuminate the strong association found between short sleep duration and substance use in African-Americans with schizophrenia and SADD. © 2015 Wiley Periodicals, Inc.

24-h activity rhythm and sleep in depressed outpatients

Disturbances in sleep and circadian rest-activity rhythms are key features of depression. Actigraphy, a non-invasive method for monitoring motor activity, can be used to objectively assess circadian rest-activity rhythms and sleep patterns. While recent studies have measured sleep and daytime activity of depressed patients using wrist-worn actigraphy, the actigraphic 24-h rest-activity rhythm in depression has not been well documented. We aimed to examine actigraphically measured sleep and circadian rest-activity rhythms in depressed outpatients. Twenty patients with DSM-IV major depressive episode and 20 age- and sex-matched healthy controls participated in this study. Participants completed 7 consecutive days of all-day actigraphic activity monitoring while engaging in usual activities. For sleep parameters, total sleep time, wake after sleep onset, and sleep fragmentation index were determined. Circadian rhythms were estimated by fitting individual actigraphy data to a cosine curve of a 24-h activity rhythm using the cosinor method, which generated three circadian activity rhythm parameters, i.e., MESOR (rhythm-adjusted mean), amplitude, and acrophase. Subjective sleep was also assessed using a sleep diary and the Pittsburgh Sleep Quality Index. Patients showed significantly lower MESOR and more dampened amplitude along with significant sleep disturbances. Logistic regression analysis revealed that lower MESOR and more fragmented sleep emerged as the significant predictors of depression. Correlations between subjectively and actigraphically measured parameters demonstrated the validity of actigraphic measurements. These results indicate marked disturbances in sleep and circadian rest-activity rhythms of depression. By simultaneously measuring sleep and rest-activity rhythm parameters, actigraphy might serve as an objective diagnostic aid for depression.

Sleep quality in the general population: psychometric properties of the Pittsburgh Sleep Quality Index, derived from a German community sample of 9284 people

BACKGROUND

The Pittsburgh Sleep Quality Index (PSQI) is frequently used to assess sleep problems in patients. The aim of this study was to provide reference values for this questionnaire, to test psychometric properties, and to analyze associations with psychological, sociodemographic, and behavioral factors.

METHODS

A German community sample comprising 9284 adult residents (aged 18-80 years) was surveyed using the PSQI and several other questionnaires.

RESULTS

According to the generally accepted cut-off (PSQI > 5), 36% of the general population slept badly. Females reported significantly more sleep problems than males (mean scores: M = 5.5 vs. M = 4.4, respectively; effect size d = 0.35), but there was no linear association between age and sleep quality. Sleep problems were correlated with fatigue, quality of life (physical as well as mental), physical complaints, anxiety, and lack of optimism. Sleep quality was also strongly associated with socioeconomic status, professional situation (poorest sleep quality in unemployed people), and obesity. In addition to the results of the PSQI total score, mean scores of specific components of sleep quality were presented (sleep latency, sleep duration, and use of sleep medication).

CONCLUSION

The PSQI proved to be a suitable instrument for measuring sleep quality. Gender differences, psychological factors, and obesity should be taken into account when groups of patients are compared with respect to sleep problems.

Fermented milk containing Lactobacillus casei strain Shirota prevents the onset of physical symptoms in medical students under academic examination stress

This pilot study investigated the effects of the probiotic Lactobacillus casei strain Shirota (LcS) on psychological, physiological, and physical stress responses in medical students undertaking an authorised nationwide examination for promotion. In a double-blind, placebo-controlled trial, 24 and 23 healthy medical students consumed a fermented milk containing LcS and a placebo milk, respectively, once a day for 8 weeks until the day before the examination. Psychophysical state, salivary cortisol, faecal serotonin, and plasma L-tryptophan were analysed on 5 different sampling days (8 weeks before, 2 weeks before, 1 day before, immediately after, and 2 weeks after the examination). Physical symptoms were also recorded in a diary by subjects during the intervention period for 8 weeks. In association with a significant elevation of anxiety at 1 day before the examination, salivary cortisol and plasma L-tryptophan levels were significantly increased in only the placebo group (P<0.05). Two weeks after the examination, the LcS group had significantly higher faecal serotonin levels (P<0.05) than the placebo group. Moreover, the rate of subjects experiencing common abdominal and cold symptoms and total number of days experiencing these physical symptoms per subject were significantly lower in the LcS group than in the placebo group during the pre-examination period at 5-6 weeks (each P<0.05) and 7-8 weeks (each P<0.01) during the intervention period. Our results suggest that the daily consumption of fermented milk containing LcS may exert beneficial effects preventing the onset of physical symptoms in healthy subjects exposed to stressful situations.

Comprehensive Health-Related Quality of Life is Influenced by Nocturia and Sleep Disturbance: Investigation Based on the SF-8

We investigated the influence of nocturia and sleep disturbance on health-related quality of life(HRQOL) using the Medical Outcomes Study 8-item Short Form Health Survey (SF-8) in patients with nocturia. We also assessed the effect of therapeutic intervention by means of an anticholinergic agent on the results of the SF-8. One hundred and eighty-four patients who voided at least once per night were surveyed using the SF-8, Overactive Bladder Symptom Score (OABSS), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS). These parameters were also evaluated before and after 12 weeks of imidafenacin treatment in 51 patients with OAB accompanied by nocturia. The SF-8 physical component summary score (PCS) showed a significant decrease as nighttime voiding frequency increased. The mental health component summary score was 47.1 and 47.6 (which were lower than the standard value of 50) in the group with a nighttime frequency of once and ≥3/night, respectively. The SF-8 PCS and 6 subscales were negatively associated with nighttime voiding frequency, while the PSQI global score was positively associated with it. Imidafenacin significantly improved the OABSS, PSQI, and ESS, as well as the SF-8 score. This is the first study using the SF-8 to show that nocturia and sleep disturbance have a major influence on comprehensive HRQOL and that the SF-8 can be used to monitor HRQOL in OAB patients receiving treatment for nocturia.

Salivary melatonin levels and sleep-wake rhythms in pregnant women with hypertensive and glucose metabolic disorders: A prospective analysis

In preeclampsia and gestational diabetes, the sympathetic nerves are activated, leading to disrupted sleep. Melatonin, which transmits information to regulate the sleep-wake rhythm and other such biorhythms, has been implicated in insulin resistance, antioxidant behaviors, and metabolic syndrome. In addition, its reduced secretion increases the risk of hypertension and diabetes. The aim of this study was to elucidate the features of melatonin secretion, sleep quality, and sleep-wake rhythms in pregnant women with complications. Fifty-eight pregnant women with pregnancy complications (hypertensive or glucose metabolic disorders) and 40 healthy pregnant women completed questionnaires, including sleep logs and the Pittsburgh Sleep Quality Index (PSQI), during the second to third trimesters. Their salivary melatonin levels were also measured. Pregnant women with complications had significantly lower morning (p < 0.001), daytime (p < 0.01), evening (p < 0.001), night (p < 0.01), daily mean (p < 0.001), peak (p < 0.001), and bottom (p < 0.01) melatonin values than healthy pregnant women. Pregnant women with complications also had significantly smaller melatonin amplitudes than healthy pregnant women (p < 0.001). Among pregnant women with complications, the duration (p < 0.05) and frequency (p < 0.01) of wake after sleep-onset were significantly greater in the poor sleep group than in the favorable sleep group which was divided by PSQI cutoff value. Pregnant women with hypertensive or glucose metabolic disorder complications had smaller circadian variation in salivary melatonin secretion, and their values were lower throughout the day than healthy pregnant women.

Evaluation of the psychometric properties of the Persian version of the Pittsburgh Sleep Quality Index in depressed patients

INTRODUCTION

The Pittsburgh Sleep Quality Questionnaire is capable of covering different stages of sleep, and it is regarded as one of the best ones available, and checking for its validity and reliability among depressed patients is a step in this direction. The aim of this study was to evaluate the reliability and validity of the Persian version of the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) questionnaires in patients with depression.

METHODS

In this study, 93 depressed patients were in the study group, and 100 patients were in the control group. The Persian translation of the PSQI and ESS questionnaires and the Beck Depression Inventory (BDI) were at the disposal of both validity and reliability of PSQI and ESS, and its correlation with BDI scores were analyzed.

RESULTS

In our study, Cronbach's alpha coefficient of the PSQI questionnaire was 0.821. According to the PSQI and BDI-II scores, the results between the PSQI and ESS scores were significantly correlated.

CONCLUSION

Using the Persian PSQI and ESS questionnaires to evaluate sleep quality and daytime sleepiness in patients with depression provides a reliable and valid measure for subjective sleep quality in clinical practice and research.

Construct validity and factor structure of the Pittsburgh Sleep Quality Index among pregnant women in a Pacific-Northwest cohort

PURPOSE

Poor sleep quality during pregnancy is associated with adverse obstetric and neuropsychiatric outcomes. Despite its routine use as a sleep quality assessment scale among men and non-pregnant women, the psychometric properties of the Pittsburgh Sleep Quality Index (PSQI) have not been assessed among US pregnant women. We sought to evaluate the construct validity and factor structure of the PSQI among 1488 pregnant women.

METHODS

A structured interview was used to collect information about demographics and sleep characteristics in early pregnancy. The Patient Health Questionnaire-9 (PHQ-9) and the Depression, Anxiety, and Stress Scale-21 (DASS-21) were used to assess symptoms of depression, anxiety, and stress. Consistency indices, exploratory and confirmatory factor analyses (EFA and CFA), correlations, and logistic regression procedures were used.

RESULTS

The reliability coefficient, Cronbach's alpha for the PSQI items was 0.74. Results of the EFA showed that a rotated factor solution for the PSQI contained two factors with eigenvalues >1.0 accounting for 52.8 % of the variance. The PSQI was significantly positively correlated with the PHQ-9 (r s = 0.48) and DASS-21 (r s = 0.42) total scores. Poor sleepers (PSQI global score >5) had increased odds of experiencing depression (OR = 6.47; 95 % CI = 4.56-9.18), anxiety (OR = 3.59; 95 % CI = 2.45-5.26), and stress (OR = 4.37; 95 % CI = 2.88-6.65) demonstrating evidence of good construct validity. CFA results corroborated the two-factor structure finding from the EFA and yielded reassuring measures indicating goodness of fit (comparative fit index = 0.975) and accuracy (root mean square error of approximation = 0.035).

CONCLUSIONS

The PSQI has good construct validity and reliability for assessing sleep quality among pregnant women.

Relationship between quality of life and restless legs syndrome among a community-dwelling population in Japan

OBJECTIVES

Restless legs syndrome (RLS) is a sensorimotor disturbance that causes the production of impulses and dysesthesia and makes the patients feel as though they must move their lower extremities. Because the symptoms of RLS in the lower limbs tend to develop at night, RLS could cause sleep disorders. We investigated an association between the symptoms of RLS and the health-related quality of life among community-dwelling individuals in Japan.

METHODS

In this cross-sectional survey, we enrolled 985 volunteers who participated in the Iwaki Health Promotion Project in 2013. The symptoms of RLS were evaluated by the criteria of the International Restless Legs Syndrome Study Group. The assessments included an interview to obtain sociodemographic data, the second version of the Short Form Health Survey, the Center for Epidemiological Studies Depression scale, and the Pittsburgh Sleep Quality Index. A multiple regression analysis was used to assess the relationship between the symptoms of RLS and subscores of the Short Form Health Survey, Version 2.

RESULTS

The overall prevalence of RLS in our participants was 1.0%. We found a significant and negative association between symptoms of RLS and physical functioning, role - physical functioning, bodily pain, social functioning, and the physical composite summary score.

CONCLUSION

After adjusting for confounders such as age, sex, and comorbidity, the burden of RLS appears to be mainly a physical problem. Impaired health-related quality of life among community individuals with RLS emphasizes the importance of screening for these symptoms and evaluating the need for treatment.

Characteristics of Sleep Disturbances in Patients with Gastroesophageal Reflux Disease

Objective Gastroesophageal reflux disease (GERD) is strongly associated with sleep disturbances; however, the detailed differences in the characteristics of sleep disturbances between GERD and non-GERD patients are unknown. The aim of the present study was to analyze the clinical characteristics as well as health-related quality of life in GERD and non-GERD patients with sleep disturbances. Methods Three hundred and fifty patients, including 124 patients with GERD and 226 patients without GERD, completed a self-administered questionnaire that evaluated clinical information. The Pittsburg Sleep Quality Index (PSQI), Hospital Anxiety and Depression Scale (HADS), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS) and 8-item Short-Form Health Survey (SF-8) were also used. Sleep disturbance was considered to be present if the PSQI was >5.5. Results The prevalence of sleep disturbances was significantly higher in the GERD patients (66/124, 53.9%) than in the non-GERD patients (89/226, 39.3%). Depression and anxiety were significantly more common in the subjects with sleep disturbances than in those without sleep disturbances, although there were no differences between the GERD and non-GERD patients. Among the subjects with sleep disturbances, daytime sleepiness was more common in the GERD patients than in the non-GERD patients. The subjects with sleep disturbances had a poorer health-related quality of life. The physical components of quality of life were impaired, particularly in the GERD patients with sleep disturbances. Conclusion GERD patients with sleep disturbances commonly experience daytime sleepiness and an impaired health-related quality of life, especially in terms of physical components.

Beneficial Effects of Ramelteon on Rapid Eye Movement Sleep Behavior Disorder Associated with Parkinson's Disease - Results of a Multicenter Open Trial

Objective Melatonin is effective for treating patients with rapid eye movement sleep behavior disorder (RBD). Ramelteon, a novel hypnotic, acts as a melatonin receptor agonist. In the current study, we investigated the effects of ramelteon on sleep disorders, including RBD, in patients with Parkinson's disease (PD). Methods We evaluated 35 patients from multiple centers with idiopathic PD accompanied by sleep disturbances (age: 69.1±11.1 years; 17 men, 18 women; PD morbidity: 6.9±5.7 years; Hoehn & Yahr stage: 2.5±0.8; levodopa dose equivalent: 561±401 mg/day). The patients received 8 mg of ramelteon before sleep once daily for 12 weeks. Motor and sleep symptoms were evaluated both before and after ramelteon administration. Results Of the 35 patients enrolled in this study, 24 (68.6%) were diagnosed with probable RBD (pRBD) using the Japanese version of the RBD screening questionnaire. Ramelteon administration reduced the severity of sleep disturbances in patients with PD. It also lowered scores on the Japanese version of the RBD questionnaire in patients with PD and pRBD. Conclusion Ramelteon may have beneficial effects on sleep disturbances, especially on RBD in patients with PD.

Prevalence and associated factors of hypnotics dependence among Japanese outpatients with psychiatric disorders

This study aimed to investigate the prevalence of the dependence for benzodiazepine or their agonist (BZDs) hypnotics, as well as factors associated with this dependence among Japanese psychiatric outpatients. One thousand and forty-three patients in the psychiatric outpatient clinic of Tokyo Medical University Hospital receiving treatment with BZDs hypnotics were analyzed. The subjects answered questionnaires including demographic variables, subjective sleep difficulty assessed by the Pittsburg Sleep Quality Index (PSQI), duration of hypnotics medication, dose of diazepam equivalent BZDs hypnotics, the presence or absence of subjective side effects due to BZDs hypnotics (dizziness, fatigue, daytime sleepiness, amnesia, and headache), and dependency assessed by the Dependency 2-A (D 2-A) score. Subjects with a D 2-A score ≥10 were considered as having BZDs hypnotics dependence, and the variables associated with the presence of dependence were examined using logistic regression analyses. Eighty-two out of the 1043 subjects (7.9%) were determined to have BZDs hypnotics dependence. Compared with the non-dependence group, the dependence group had a significantly higher proportion of positive respondents for all the side effects. Multiple logistic regression analyses showed that the dependence was significantly associated with younger age, higher total PSQI score, and higher daily dose of BZDs hypnotics. Younger age, higher total PSQI score, and higher dose may be associated with BZDs hypnotics dependence. The finding that patients with BZDs hypnotics dependence frequently suffered from subjective side effects and had greater sleep difficulty encourages the establishment of alternative treatments for patients with insomnia symptoms refractory to BZDs hypnotics treatment.

Effects of exercise and horticultural intervention on the brain and mental health in older adults with depressive symptoms and memory problems: study protocol for a randomized controlled trial [UMIN000018547]

Background

Depressive symptoms and memory problems are significant risk factors for dementia. Exercise can reduce depressive symptoms and improve cognitive function in older people. In addition, the benefits of horticultural activity on physical and mental well-being have been demonstrated in people with dementia. Although evidence of such non-pharmacological interventions is mounting, no studies have examined whether physical exercise and horticultural activity exert a positive impact on brain and mental health (e.g., depressive symptoms) in non-demented older adults at high risk of cognitive impairment and depression. Therefore, we propose a randomized controlled trial to assess the efficacy and efficiency of physical exercise and horticultural activity in improving brain and mental health in community-dwelling older adults with memory problems and depressive symptoms.

Methods/Design

The 20-week randomized controlled trial will include 90 community-dwelling adults aged 65 years or older with memory problems and depressive symptoms. Participants will be randomized to one of three experiments: exercise, horticultural activity, or educational control group, using a 1:1:1 allocation ratio. The combined exercise program and horticultural activity program will consist of 20 weekly 90-minute sessions. Participants in the exercise group will practice aerobic exercise, muscle strength training, postural balance retraining, and dual-task training. The horticultural activity program will include crop-related activities, such as field cultivation, growing, and harvesting. Participants in the educational control group will attend two 90-minute educational classes during the 6-month trial period. Depressive symptoms and memory performance will be measured by the Geriatric Depression Scale-15, and the Logical Memory subtests of the Wechsler Memory Scale-Revised will be used to measure depressive symptoms and memory performance as primary outcomes, at baseline (prior to randomization), immediately following intervention (6 months from baseline), and 6 months after intervention. Hippocampal volume will be measured at baseline and immediately after intervention, using magnetic resonance imaging. Secondary outcomes will comprise cognitive function, including language, attention/executive performance, and processing speed; brain-derived neurotrophic-factor serum levels; and health-related quality of life.

Discussion

This intervention study will determine the clinical importance and efficacy of physical exercise and horticultural activity as non-pharmacological interventions in community-dwelling older adults at high risk of poor brain and mental health.

Trial registration

UMIN000018547; registered 7 August 2015.

Underweight body mass index is a risk factor of mortality in outpatients with nocturia in Japan

Background

Although nocturia has been reported to increase mortality in elderly individuals, the particular risk factors that are associated with this event are unclear. Therefore, we evaluated risk factors for death in outpatients with nocturia.

Methods

Between October 2002 and December 2009, 250 consecutive patients with nocturia were enrolled in two general hospitals in Japan. Among them, 193 patients were able to be followed for at least 1 year and up to 9 years (median 4.8 years) if the patients did not die. Mortality rates and risk factors were evaluated in the nocturic outpatients.

Results

Two- and 5-year survival of the nocturic outpatients was 94.6 % [95 % confidence interval (CI) = 92.2–97.1] and 82.6 % (95 % CI = 75.4–87.8), respectively. Higher Charlson Comorbidity Score, lower body mass index (BMI) and lower Physical Component Summary of Short Form-36 item scores were significantly correlated with mortality (p < 0.0001, p < 0.005 and p < 0.05, respectively) in multivariate analysis. The International Prostate Symptom Score, Pittsburgh Sleep Quality Index, Mental or Role/Social Component Summary of Short Form-36 item scores and Nocturnal Polyuria index were not significantly correlated with mortality. The mortality rate was significantly higher in subjects with an underweight BMI (<18.50) compared with a normal range (18.50–24.99) or overweight (≥25.00) BMI [p < 0.00005, hazard ratio (HR) = 5.84, 95 % CI = 2.03–16.8; p < 0.0005, HR = 5.92, 95 % CI = 1.94–18.0].

Conclusions

Additional attention is required for nocturic outpatients with not only a high Charlson Comorbidity Score but also an underweight BMI because of their high mortality. Large prospective studies are warranted to validate this finding and extend more.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1456-6) contains supplementary material, which is available to authorized users.

Psychometric Properties of the Pittsburgh Sleep Quality Index (PSQI) in a Cohort of Peruvian Pregnant Women

STUDY OBJECTIVES

We sought to evaluate the construct validity and factor structure of the Spanish-language version of the Pittsburgh Sleep Quality Index (PSQI) among pregnant Peruvian women.

METHODS

A cohort of 642 women were interviewed at ≤ 16 weeks of gestation. During interview, we ascertained information about lifestyles, demographics, sleep characteristics, and mood symptoms. Stress induced sleep disturbance, depressive symptoms, and anxiety symptoms were evaluated using the Ford Insomnia Response to Stress Test (FIRST), Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 (GAD-7) assessment scales, respectively. Consistency indices, exploratory and confirmatory factor analyses, correlations, and logistic regressions were used.

RESULTS

Both exploratory and confirmatory factor analyses indicated a three-factor solution: sleep quality, sleep efficiency, and sleep medication. We observed significantly positive correlations of the PSQI with the FIRST (0.42), the PHQ-9 (0.49), and the GAD-7 (0.46). Poor sleepers (PSQI global score > 5) had significantly increased odds of experiencing stress-induced sleep disturbance (odds ratio, OR = 3.57; 95% CI: 2.40, 5.31), depression (OR = 5.48; 95% CI: 3.58, 8.37), and generalized anxiety disorder (OR = 4.57; 95% CI: 3.08, 6.76).

CONCLUSION

The Spanish-language version of the PSQI instrument was found to have good construct validity among pregnant Peruvian women. Consistent with some other studies, the PSQI was found to have a three-factor structure. Further assessment and validation studies are needed to determine whether the three, factor-specific scoring of the PSQI is favored over the PSQI global score in diverse populations.

Sleep Architecture in Partially Acclimatized Lowlanders and Native Tibetans at 3800 Meter Altitude: What Are the Differences?

It is not well known whether high altitude acclimatization could help lowlanders improve their sleep architecture as well as Native Tibetans. In order to address this, we investigated the structural differences in sleep between Native Tibetans and partially acclimatized lowlanders and examined the association between sleep architecture and subjective sleep quality. Partially acclimatized soldiers from lowlands and Native Tibetan soldiers stationed at Shangri-La (3800 m) were surveyed using the Pittsburgh Sleep Quality Index (PSQI), Hamilton Anxiety Scale (HAMA), and Hamilton Depression Rating Scale (HAMD). The sleep architecture of those without anxiety (as determined by HAMA>14) and/or depression (HAMD>20) was analyzed using polysomnography and the results were compared between the two groups. One hundred sixty-five male soldiers, including 55 Native Tibetans, were included in the study. After partial acclimatization, lowlanders still exhibited differences in sleep architecture as compared to Native Tibetans, as indicated by a higher PSQI score (8.14±2.37 vs. 3.90±2.85, p<0.001), shorter non-rapid eye movement (non-REM) sleep (458.68±112.63 vs. 501±37.82 min, P=0.03), lower nocturnal arterial oxygen saturation (Spo2; mean 91.39±1.24 vs. 92.71±2.12%, p=0.03), and increased times of Spo2 reduction from 89% to 85% (median 48 vs.17, p=0.04) than Native Tibetans. Sleep onset latency (β=0.08, 95%CI: 0.01 to 0.15), non-REM latency (β=0.011, 95%CI 0.001 to 0.02), mean Spo2 (β=-0.79, 95%CI: -1.35 to -0.23) and time in stage 3+4 sleep (β=-0.014, 95%CI: -0.001 to -0.028) were slightly associated with the PSQI score. Partially acclimatized lowlanders experienced less time in non-REM sleep and had lower arterial oxygen saturation than Native Tibetans at an altitude of 3800 m. The main independent contributors to poor sleep quality are hypoxemia, difficulty in sleep induction, and time in deep sleep.

Long working hours and sleep problems among public junior high school teachers in Japan

OBJECTIVES

Long working hours may impact human health. In Japan, teachers tend to work long hours. From 2002 to 2012, the number of leaves of absence due to diseases other than mental disorders, or mental disorders among public school teachers increased by 1.3 times (from 2,616 to 3,381), or 1.8 times (from 2,687 to 4,960), respectively. The present study aimed to investigate the association between long working hours and sleep problems among public school teachers.

METHODS

This cross-sectional study was conducted from mid-July to September 2013 in Hokkaido Prefecture, Japan. Questionnaires were distributed to 1,245 teachers in public junior high schools. Information about basic characteristics including working hours, and responses to the Pittsburgh Sleep Quality Index were collected anonymously. Multiple logistic regression analysis was used to calculate odds ratios (ORs) for the association between long working hours and sleep problems separately by sex.

RESULTS

The response rate was 44.8% (n=558). After excluding ineligible responses, the final sample comprised 515 teachers (335 males and 180 females). Sleep problems was identified in 41.5% of males and 44.4% of females. Our results showed a significantly increased risk of sleep problems in males working >60 hours per week (OR 2.05 [95% CI 1.01-4.30]) compared with those working ≤40 hours per week. No significant association was found in females.

CONCLUSIONS

There is a significant association between long working hours and sleep problems in male teachers. Reducing working hours may contribute to a reduction in sleep problems.

[The relationship between self-awareness of fatigue symptoms and working conditions in female nurses]

OBJECTIVES

The aim of this study was to clarify the relationship between self-awareness of fatigue symptoms and working conditions, in female nurses.

METHODS

We studied personal background, working conditions, physical symptoms, "Pittsburgh Sleep Quality Index - Japanese version (PSQI-J)", and 13 items that represented the parts related to self-awareness of the "the self-Diagnosis Checklist for Workers' Accumulated Fatigue" in 3,855 female nurses. The targets for analysis were 983 nurses ("all subjects") and among those, 765 "shift workers". The total score (fatigue symptoms self-awareness score) was calculated for 13 items that represented the parts related to self-awareness of the "the self-Diagnosis Checklist for Workers' Accumulated Fatigue". The Mann-Whitney U test and the Kruskal-Wallis test were performed, and the fatigue symptoms self-awareness score was studied, based on personal background, working conditions, physical symptoms and the PSQI-J score.

RESULTS

For "all subjects", there was a significant difference in the fatigue symptoms self-awareness score for department in which they work, the form the work takes, and the PSQI-J score. The fatigue symptoms self-awareness score of nurses with a PSQI-J score of 5.5 or higher was a significantly high value. For "shift workers", there was a significant difference in the fatigue symptoms self-awareness score for presence or absence of a caregiver role, department in which they work, the form the work takes, the form the nap takes during night work and PSQI-J score. There was a significantly high value in the fatigue symptoms self-awareness score of subjects with a caregiver role, subjects working in surgical wards or internal medicine wards, subjects working on a three-shift system, and subjects who were unable to take naps during night work, subjects with a PSQI-J score of 5.5 or higher.

DISCUSSION

These survey results suggest that it is important to set up a system that will ensure the ability to have naps during night work. It will also be necessary to consider the caregiver role and so on as items related to the fatigue of nurses.

Evaluation of cutoff scores for the Parkinson's disease sleep scale-2

BACKGROUND

The Parkinson's Disease Sleep Scale (PDSS)-2 is a recently developed tool for evaluating disease-related nocturnal disturbances in patients with Parkinson's disease (PD). However, its cutoff score has not been clinically assessed. We determined the optimal cutoff score of the Japanese version of the PDSS-2.

METHODS

Patients with PD (n = 146) and controls (n = 100) completed the PDSS-2 and the Pittsburgh Sleep Quality Index (PSQI). Poor sleepers were defined as having global PSQI scores >5. Optimal cutoff scores for determining poor sleepers were assessed using the receiver operating characteristic curve.

RESULTS

A PDSS-2 total score ≥ 14 exhibited 82.0% sensitivity and 70.6% specificity, whereas a PDSS-2 total score ≥ 15 provided 72.1% sensitivity and 72.9% specificity in distinguishing poor sleepers (PSQI score >5) from good sleepers (PSQI ≤ 5). Nocturnal disturbances were more frequently observed in patients with PD than in controls (PDSS-2 total score ≥ 14 or ≥ 15; 51.4% vs 20%; 45.9% vs 19%). Nocturnal disturbances were associated with higher Hoehn and Yahr stages and Unified Parkinson's Disease Rating Scale motor scores, impaired quality of life, daytime sleepiness, and depressive symptoms.

CONCLUSION

We suggest that PDSS-2 total scores ≥ 15 are useful for detecting poor sleepers among patients with PD.

Fatigue and sleep under large summer temperature differences

BACKGROUND

It has been recognized that an increase in outdoor ambient temperatures has a negative impact on health, particularly fatigue and sleep quality; however, the relationship among fatigue, sleep quality, and air temperature has yet to be sufficiently elucidated.

OBJECTIVES

To examine whether fatigue and sleep quality in a healthy Japanese population were affected by rising air temperature at three time points in summer and to investigate the confounding factors for fatigue.

METHODS

A total of 602 healthy volunteers in Osaka, Japan, participated in a survey that was conducted at the end of July, August, and September in 2010. The questionnaire consisted of four sections; demographic variables, accommodation status, fatigue, and sleep quality. We used the Chalder fatigue scale for assessment of fatigue, and the Japanese version of the Pittsburgh Sleep Quality Index (PSQI) for assessment of sleep quality.

RESULTS

The fatigue score was positively correlated with the sleep quality score in the total cohort. All the questionnaires at the three time points were completed by 162 participants. There were significant differences in fatigue scores among the surveys. We stratified the subjects into two groups of good and poor sleepers using a cutoff value of the PSQI. The good sleepers did not show differences in fatigue score regardless of the change in air temperature. However, the fatigue score of poor sleepers was greater at higher air temperatures. The use of air conditioners, accommodation type, and subject's age were confounding factors for fatigue.

CONCLUSIONS

High air temperatures in summer increased fatigue in healthy volunteers, especially those with poor sleep patterns, depending on the use of air conditioners, accommodation status, and subject's age.

Inverse association of des-acyl ghrelin with worksite blood pressure in overweight/obese male workers

BACKGROUND

Job strain, defined as a combination of high job demands and low job control, has been reported to elevate blood pressure (BP) during work. Meanwhile, a recent experimental study showed that ghrelin blunted the BP response to such mental stress. In the present study, we examined the hypothesis that des-acyl ghrelin may have some beneficial effects on worksite BP through modulating the BP response to work-related mental stress, i.e., job strain.

METHODS

Subjects were 34 overweight/obese male day-shift workers (mean age 41.7 ± 6.7 years). No subjects had received any anti-hypertensive medication. A 24-h ambulatory BP monitoring was recorded every 30 min on a regular working day. The average BP was calculated for Work BP, Morning BP, and Home BP. Job strain was assessed using the short version of the Japanese Job Content Questionnaire.

RESULTS

Des-acyl ghrelin showed significant inverse correlations with almost all BPs except Morning SBP, Morning DBP, and Home DBP. In multiple regression analysis, des-acyl ghrelin inversely correlated with Work SBP after adjusting for confounding factors. Des-acyl ghrelin was also negatively associated with BP changes from Sleep to Morning, Sleep to Work, and Sleep to Home.

CONCLUSIONS

Des-acyl ghrelin was inversely associated with Worksite BP, suggesting a unique beneficial effect of des-acyl ghrelin on Worksite BP in overweight/obese male day-shift workers.

Female family caregivers face a higher risk of hypertension and lowered estimated glomerular filtration rates: a cross-sectional, comparative study

BACKGROUND

Despite societal efforts to alleviate the challenges, caregiving seems to constitute a substantial burden and source of stress for many families of older adults in Japan. However, precise information on the physical health of caregivers, based on objective data, is not available. The purpose of this study was to improve the understanding of the physical health of Japanese family caregivers using objective indicators and a comparative research design.

METHODS

A cross-sectional, comparative study was conducted among family caregivers and their non-caregiver counterparts. Surveyors visited caregivers in their homes to administer a questionnaire survey, measure their blood pressure, and collect blood samples using a kit. Blood samples were tested for LDL-Cholesterol, HDL-Cholesterol, AST, ALT, γ-GTP, uric acid, creatinine and HbA1c. Non-caregiver data were collected at a university-based health checkup center. We compared 149 caregivers with 149 sex- and age-matched non-caregivers using conditional logistic regression analyses to examine the impact of caregiving, adjusting for multiple control variables. Analyses were conducted separately for men and female.

RESULTS

The prevalence of high blood pressure was significantly higher among caregivers than non-caregivers (male: 72.7% among caregivers vs. 40.9% among non-caregivers, female: 57.1% vs. 27.6%, respectively). After adjusting for related sociodemographic and health factors, high blood pressure remained significantly more prevalent among caregivers than non-caregivers, only among female (adjusted OR=2.16, 95% CI [1.14, 4.08]). Female caregivers showed lower eGFR than their non-caregiver counterparts (adjusted OR=6.54, 95% CI [2.38, 17.91]). No significant differences were observed between the two groups on any other indicators.

CONCLUSIONS

Results suggest that female caregivers are at a higher risk of conditions such as cerebral, cardiovascular or kidney diseases than non-caregivers. Steps must be taken to identify caregivers with high blood pressure and lowered eGFR and provide them with the support they need before these risk factors develop into serious diseases.