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Akinori Nakata

Publications and source records attributed to Akinori Nakata.

At least 19 recordsLinked to original sources

Relationship between cumulative effects of smoking and memory CD4+ T lymphocyte subpopulations.

Previous studies have found that smoking is a strong factor that increases peripheral blood CD4+ T lymphocytes. However, most studies did not assess the cumulative long-life exposure of smoking on differential lymphocyte populations. In this study, to clarify the association of smoking habits and circulating lymphocytes, we conducted a cross-sectional study of 60 male current smokers. Smoking status was estimated by number of cigarettes smoked per day, smoking years, and Brinkman Index (BI) as calculated by multiplying the number of cigarettes smoked per day by the smoking years. Counts of CD4+CD45RO+CD69+ T and CD4+CD45RO+ T lymphocytes were strongly and positively correlated with BI and remained highly significant after controlling for alcohol drinking, leisure-time physical activity, and caffeine intake (r(p)>.465, p<.001). These lymphocytes were also significantly correlated with the number of cigarettes smoked per day and smoking years, but the association was weaker than the BI. The findings suggest that the CD4+CD45RO+CD69+ T and CD4+CD45RO+ T lymphocytes are sensitive to cumulative effect of smoking, and may serve as a potential immuno-biomarker for active smoking.

Adult↗

Non-fatal occupational injury among active and passive smokers in small- and medium-scale manufacturing enterprises in Japan.

Active smoking is a risk factor for occupational injury, whereas its association with passive smoking is unknown. To evaluate the contribution of active and passive smoking to non-fatal occupational injury in manufacturing sectors, 2302 randomly selected workers aged 16-83 years working in 244 small- and medium-scale enterprises in Yashio city, Japan, were surveyed by means of a self-administered questionnaire. Smoking history, exposure to passive smoking, and occupational injury were evaluated by self-report. Exposure levels to passive smoking were assessed separately at work and at home as never, occasional, or regular exposure. Overall, 61.4% of men and 22.3% of women were current smokers. Among never smokers, 62.2% of men and 68.6% of women reported exposure to passive smoking either at work or home. Prevalence of occupational injuries was 36.2% for never, 43.3% for former, and 41.2% for current smokers among men and 19.7% for never, 22.2% for former, and 25.2% for current smokers among women. Among never smoking men, odds ratios (ORs) of occupational injury were 2.11 when regularly exposed to passive smoking at work or at home (p=0.025), 2.27 at work (p=0.015), and 3.08 at home (p=0.106), in comparison to never smoking men who were never exposed to passive smoking either at work or at home (referent group). These associations were attenuated to be non-significant, after controlling for potential confounders. Never smoking men with occasional exposure to passive smoking were not significant ORs (1.11-1.19). In contrast, current and former smoking men had significant increases in adjusted ORs (1.57-2.00). In women exposed to smoking there was a non-significant increase in occupational injury. The present study indicates an expected increase in the risk of, occupational injury for current and former smoking men and suggests that exposure to passive smoking is a possible risk factor for never smoking men.

Accidents, Occupational↗

Validation of the Karolinska sleepiness scale against performance and EEG variables.

OBJECTIVE: The Karolinska sleepiness scale (KSS) is frequently used for evaluating subjective sleepiness. The main aim of the present study was to investigate the validity and reliability of the KSS with electroencephalographic, behavioral and other subjective indicators of sleepiness. METHODS: Participants were 16 healthy females aged 33-43 (38.1+/-2.68) years. The experiment involved 8 measurement sessions per day for 3 consecutive days. Each session contained the psychomotor vigilance task (PVT), the Karolinska drowsiness test (KDT-EEG alpha & theta power), the alpha attenuation test (AAT-alpha power ratio open/closed eyes) and the KSS. RESULTS: Median reaction time, number of lapses, alpha and theta power density and the alpha attenuation coefficients (AAC) showed highly significant increase with increasing KSS. The same variables were also significantly correlated with KSS, with a mean value for lapses (r=0.56). CONCLUSIONS: The KSS was closely related to EEG and behavioral variables, indicating a high validity in measuring sleepiness. SIGNIFICANCE: KSS ratings may be a useful proxy for EEG or behavioral indicators of sleepiness.

Adult↗

Impact of psychosocial job stress on non-fatal occupational injuries in small and medium-sized manufacturing enterprises.

BACKGROUND: Workers involved in manufacturing are known to comprise a high-risk population for occupational injury, and this risk is greater in small and medium-sized enterprises (SMEs). The purpose of this study was to examine the association between psychosocial job stress and occupational injuries among workers in SMEs. METHODS: One thousand forty-nine men and 721 women from 244 SMEs participated in this study. Perceived job stress was evaluated with the Japanese version of the generic job stress questionnaire, which covered 14 job stress variables. Occupational injury was assessed by self-report during the last 1-year period. RESULTS: Workers with high quantitative workload (odds ratio [OR] = 1.55 for men, 1.62 for women), high cognitive demands (OR = 1.70 for men, 1.53 for women), and low job satisfaction (OR = 1.33 for men, 1.93 for women) had a significantly increased risk of occupational injury in the multivariate model. High variance in workload (OR = 1.70) and high job future ambiguity (OR = 1.35) in men, and low job control (OR = 2.04) and high intragroup conflict (OR = 1.66) in women were significantly associated with occupational injury. In manufacturing/production workers, high quantitative workload (OR = 1.91), high variance in workload (OR = 2.02), and high depressive symptoms (OR = 1.55) were significantly associated with injury in men, while low social support from colleagues (OR = 2.36) or family (OR = 2.51) was related to injury in women. CONCLUSIONS: These data point to an independent relationship between psychosocial job stress and self-reported occupational injury in SMEs.

Accidents, Occupational↗

Psychosocial work characteristics predicting daytime sleepiness in day and shift workers.

Characteristics of work organization other than working time arrangements may contribute importantly to daytime sleepiness. The present study was designed to identify the psychosocial factors at work that predict daytime sleepiness in a sample of day and shift workers. Participants working at a pulp and chemical factory completed an annual questionnaire regarding psychosocial factors at work using the U.S. National Institute for Occupational Safety and Health Generic Job Stress Questionnaire (i.e., quantitative workload, variance in workload, job control, support from supervisor, coworkers, or family/friends, job satisfaction, and depressive symptoms), as well as daytime sleepiness (through the Epworth Sleepiness Scale [ESS]) and sleep disturbances for three years starting in 2002 (response rates, 94.6-99.0%). The present analysis included 55 day workers (11 women) and 57 shift workers (all men) who participated in all three years of the study, worked under the same work schedule throughout the study period, and had no missing data on any of the daytime sleep items. A repeated-measures analysis of covariance (ANCOVA) was used to test the effects of work schedule (day vs. shift work) and psychosocial factors at work in 2002 on the ESS scores in subsequent years, with sleep duration, insomnia symptoms, chronic diseases, and sleepiness levels at baseline as covariates. Given significant and near-significant interactions of work schedules with psychosocial factor or study year, the ANCOVA, with the factors of psychosocial work characteristics and study year, was performed by type of work schedule. The results indicated a significant main effect of psychosocial work characteristics (p = 0.010, partial eng2 = 0.14) and an almost significant main effect of study year (p = 0.067, partial eng2 = 0.06) and interaction between psychosocial work characteristics and study year (p = 0.085, partial eng2 = 0.06) for variance in workload among the day work group. The day workers reporting high variance in workload in 2002 exhibited significantly higher ESS scores in 2003 and 2004 than did those reporting low variance in workload. The ANCOVA for the shift work group showed a main effect of psychosocial work characteristics for job satisfaction (p = 0.026, partial eng2 = 0.10) and depressive symptoms (p = 0.094, partial eng2 = 0.06) with the interaction between psychosocial work characteristics and study year for job satisfaction (p = 0.172, partial eng2 = 0.04) and depressive symptoms (p = 0.035, partial eng2 = 0.07). The shift workers with low job satisfaction and high symptoms of depression in 2002 showed significantly greater ESS scores in 2003 and/or 2004 than did those with opposite characteristics. These results may suggest a potential predictive value of variance in workload for day workers as well as job satisfaction and depressive symptoms for shift workers with respect to daytime sleepiness. The present findings may imply that redesigning these aspects of work environment would be of help in managing daytime sleepiness.

Adult↗

Indoor exposure to natural bright light prevents afternoon sleepiness.

STUDY OBJECTIVES: The present study examined the effects of indoor exposure to natural bright light on afternoon sleepiness. DESIGN: Participants took part in 3 experimental conditions: (1) a natural bright light condition in which they carried out performance and arousal tests sitting near a window (3260.0 +/- 1812.43 lux) from 12:40 PM to 1:10 PM, (2) a nap condition in which they were provided a nap opportunity for 20 minutes from 12:45 PM, and (3) a control condition in which they performed the tests in less than 100 lux surroundings from 12:40 PM to 1:10 PM. Before and after each treatment, the same series of tests were administered. SETTING: A temperature- and light-controlled sleep laboratory. PARTICIPANTS: Sixteen healthy female paid volunteers aged 33 to 43 (38.1 +/- 2.68) years. INTERVENTIONS: Indoor natural bright light and a short nap. MEASUREMENTS AND RESULTS: Arousal levels were measured by the Psychomotor Vigilance Task, Alpha Attenuation Test, Karolinska Drowsiness Test, and Karolinska Sleepiness Scale. The tests were repeated every 30 minutes from 11:00 AM to 4:10 PM. Ambient light intensity was maintained at less than 100 lux, except during natural bright light exposure. Short-term exposure to natural bright light significantly improved afternoon arousal levels, as measured by the Karolinska Drowsiness Test and Alpha Attenuation Test, the effects of which continued for at least 60 minutes (1:10-2:10 PM). However, no significant differences were observed between conditions for Psychomotor Vigilance Test performance. CONCLUSIONS: Brief indoor exposure to natural bright light may decrease afternoon sleepiness. This technique of light could be used in work settings in which napping is not permitted.

Adult↗

[Relationship between length of sleep and oxidative stress marker, urinary 8-hydroxy-2'-deoxyguanosine].

OBJECTIVES: In this study, we aim to examine whether the length of sleep modifies the level of urinary 8-hydroxy-2'-deoxyguanosine (8-OH-dG). METHODS: Subjects were 146 workers who were engaged in management, clerical work, laboratory work, or business at a certain company. We obtained information on the subjects concerning gender, body mass index, drinking and smoking habits, and the lengths of habitual and previous night sleep among others using self-reported questionnaires, which were then confirmed by interview. Urine specimens were collected in the morning and those from the second or later void were used to measure 8-OH-dG and creatinine levels. The amount of 8-OH-dG normalized by creatinine content was used as the indicator of 8-OH-dG excretion (Spot Urine 8-OH-dG: SU8-OH-dG). We excluded subjects who took sleeping pills the previous night or habitually, and those whose levels were beyond the three-standard-deviation range. The subjects were then classified into three equal-sized groups according to the length of sleep, either habitual or the previous night. RESULTS AND CONCLUSION: (1) A long or a short previous night's sleep, drinking alcohol more than once a week, and habitual use of medicine increased SU8-OH-dG level among female subjects. (2) A short previous night's sleep and habitual smoking, and a short previous night's sleep and habitual use of medicine had interactions which increased SU8-OH-dG level among male subjects but the length of a previous night's sleep itself did not have an effect on SU8-OH-dG level. (3) The length of habitual sleep had no effect on SU8-OH-dG level.

8-Hydroxy-2'-Deoxyguanosine↗

Perceived sleepiness of non-shift working men in two different types of work organization.

Increased sleepiness at work is increasingly being focused on as a safety and health issue. However, research on workers' sleepiness is very limited in scope and the characteristics of work organization, including the impact of job stress, have not been fully addressed. A questionnaire survey was conducted to investigate the prevalence of daytime sleepiness and its associated factors among non-shift working men at two manufacturing businesses: Company A, having a rapid rate of development and growth, with 564 workers (19-61 yr old, mean age: 32.7, response rate: 81.4%); and Company B, long established, possessing a huge production facility, with 1,654 workers (20-63 yr old, mean age: 37.1, response rate: 78.2%). The prevalence of daytime sleepiness was 11.3% in company A and 16.8% in company B. Multivariate logistic regression analysis revealed that, in company A, perceived sleepiness was associated with long sleep duration on non-working days and high cognitive demands and, in company B, with insufficient daily sleep, single, and depression. Psychosomatic exhaustion resulting from jobs requiring high adaptivity due to rapid frequency of operational change as in company A may have the potential to become an important factor in perceived sleepiness. However, in a comparatively stable work organization, as in company B, increased sleepiness may be mainly linked to factors outside work. It is suggested that not only lifestyle and sleep habits, but also the characteristics and dynamics of a work organization should be a focus of attention when planning measures to prevent sleepiness at work.

Adult↗

The prevalence and correlates of occupational injuries in small-scale manufacturing enterprises.

Workers involved in small-scale manufacturing businesses are known to comprise a high-risk population for occupational injury. The present study investigated the prevalence and correlates of occupational injury in this population. A self-administered questionnaire that solicited answers about occupational information including injury, demographic characteristics, health conditions and lifestyle factors was collected from a sample of 1,298 workers in 228 small-scale manufacturing enterprises (defined as fewer than 50 workers) aged 16-78 (mean 46) yr in Yashio city, Saitama, Japan (response rate 65.5%). The enterprises were randomly selected from the 2000 edition of the city commercial directory corresponding to the distribution of types of businesses in the city. Occupational injury was assessed by asking subjects, ;Have you ever been injured during your work, including minor scratches and cuts in the previous 1-yr period?' The possible response was either ;yes' or ;no.' The prevalence of study-defined occupational injury among the workers was 35.6% (male 43.0%, female 17.9%). Among job types, manufacturing (44.2%) and driving (43.5%) had high rates of occupational injuries. Similarly, occupational injuries were high in the papermaking (54.5%) and machinery (47.7%) industries. For males, younger age, current or former smoking, insomnia symptoms, and disease(s) currently under treatment were correlated with injury, whereas for females, being unmarried, higher educational status, and insomnia symptoms were the correlating factors. Occupational injury is common among small-scale manufacturing businesses, and is associated with multiple controllable factors. Countermeasures such as prohibiting smoking during work, sleep health education, job safety training for young/inexperienced workers are appropriate methods for eliminating or reducing injuries.

Accidents, Occupational↗

Health problems due to long working hours in Japan: working hours, workers' compensation (Karoshi), and preventive measures.

Late in the 1970s, serious social concern over health problems due to long working hours has arisen in Japan. This report briefly summarizes the Japanese circumstances about long working hours and what the Government has achieved so far. The national statistics show that more than 6 million people worked for 60 h or more per week during years 2000 and 2004. Approximately three hundred cases of brain and heart diseases were recognized as labour accidents resulting from overwork (Karoshi) by the Ministry of Health, Labour and Welfare (MHLW) between 2002 and 2005. Consequently, the MHLW has been working to establish a more appropriate compensation system for Karoshi, as well as preventive measures for overwork related health problems. In 2001, the MHLW set the standards for clearly recognizing Karoshi in association with the amount of overtime working hours. These standards were based on the results of a literature review and medical examinations indicating a relationship between overwork and brain and heart diseases. In 2002, the MHLW launched the program for the prevention of health impairment due to overwork, and in 2005 the health guidance through an interview by a doctor for overworked workers has been enacted as law. Long working hours are controversial issues because of conflicts between health, safety, work-life balance, and productivity. It is obvious that we need to continue research regarding the impact on worker health and the management of long working hours.

Accidents, Occupational↗

Decreases in CD8+ T, naive (CD4+CD45RA+) T, and B (CD19+) lymphocytes by exposure to manganese fume.

To examine the effects of exposure to manganese (Mn) on the cellular and humoral immune system in men, T lymphocyte subpopulations, B (CD19+) lymphocytes, natural killer (NK) cells, and serum immunoglobulins (i.e., IgG, IgA and IgM) together with total T (CD3+) lymphocytes and total lymphocytes were measured in blood samples from 21 welders mainly exposed to Mn fume with blood Mn (BMn) concentrations of 0.6-2.3 (mean 1.4) microg/dl and 21 healthy controls working in the same factory (BMn concentrations: 0.7 to 1.7, mean 1.1 microg/dl). The workers engaged in welding for 6 to 36 (mean 17) yr. All the study subjects were divided into 3 equally sized groups (n=14 for each group) according to BMn concentrations. Numbers of CD8+ T, total T (CD3+), B (CD19+), and total lymphocytes were significantly lower in high-BMn group than those in low-BMn group; the numbers of CD8+ T lymphocytes were significantly lower in moderate-BMn group compared to low-BMn group. After adjusting for age and smoking, significant inverse correlations between BMn concentrations and CD4+CD45RA+ T, CD4+ T, CD8+ T, CD3+ T, and total lymphocytes were found. We conclude that T lymphocytes, especially CD8+ and CD4+CD45RA+ T lymphocytes, as well as CD19+ B lymphocytes are affected by exposure to Mn fume.

Adult↗

Association between perceived social support and Th1 dominance.

Social support is supposed to have a positive health effect via alteration of immunity. In this study, associations between perceived social support and immune systems were examined. Immunological assessments, e.g. T cell count, Natural Killer cell count, Interferon-gamma, Interleukin-4, and psychological assessments, e.g. Generic Job Stress Questionnaire were conducted on male employees. Two-way (social support x job stressor) analyses of covariance controlling for age, smoking, alcohol consumption, and exercise revealed that there were main effects of perceived social support on NK cell counts, IL-4, and Th1/Th2 balance. On the other hand, interaction effects were observed on T cell counts and INF-gamma production in vitro. Social support affects immune function in a way that is consistent with both the direct and buffering hypotheses depending on the sources of support and the immune parameter.

Adult↗

Sleep-related risk of occupational injuries in Japanese small and medium-scale enterprises.

A cross-sectional study evaluated the contribution of daily sleep habits to occupational injuries. A self-administered questionnaire solicited answers about sleep, symptoms of depression, occupational injury, demographics, presence of diseases and lifestyle factors from 2,903 workers between the ages of 16-83 (mean 45) yr in small and medium-scale enterprises. Eight sleep habits were queried and dichotomized: 1) less or more than 6 hr of daily sleep, 2) taking more or less than 30 min to fall asleep (Difficulty initiating sleep; DIS), 3) awakening during sleep more or less than 3 times/wk (Difficulty maintaining sleep; DMS), 4) early morning awakening more or less than 3 times/wk (EMA), 5) definitely/somewhat difficulty waking up or not, 6) sleeping very poorly/not so well at night or not, 7) definitely/somewhat insufficient nightly sleep or not, and 8) difficulty in breathing during sleep more than once/week or less. Occupational injury was assessed by asking subjects 'Have you ever been injured during your work, including minor scratches and cuts (Yes/No)?' Both sleep and injury were assessed over the previous one year period. One-third of workers answered that they had experienced injury. Workers with sleep features of DIS, sleeping poorly at night, insufficient sleep, and insomnia had a significantly higher prevalence for injury after adjusting for multiple confounders. The findings suggest that poor nocturnal sleep habits are associated with self-reported occupational injury.

Accidents, Occupational↗

Post-lunch nap as a worksite intervention to promote alertness on the job.

A worksite study was conducted to examine whether a 15-min nap during a post-lunch rest period would affect subsequent alertness, performance, and nocturnal sleep in eight factory workers under a 3-week protocol. Subjects were asked to take the nap at 12:30 h on a reclining chair during the nap week, and to remain awake during the no-nap week. The order of these 2 weeks was counterbalanced between the subjects. During the third, follow-up week, each subject determined whether or not she/he would nap. Alertness on the job and nocturnal sleep were assessed using a sleep diary. Wrist activity was also recorded during sleep at night. Choice reaction time task (RT) was performed at 10:00 and 15:00 h every day of the nap week and every other day of the no-nap and follow-up weeks. Perceived alertness was significantly higher in the afternoon after nap than after no nap at the end of the week. Similar effects were observed during the follow-up week where almost half of the subjects napped. No significant differences between the three weeks were found for RT performance or nocturnal sleep. Workers' attitudes toward the nap were favourable. Although further intervention research is required, our results suggest that post-lunch napping may have the potential to promote daytime alertness at work.

Adult↗

Association of lymphocyte sub-populations with clustered features of metabolic syndrome in middle-aged Japanese men.

To examine the relationship between altered cellular immune status and clustered features of the metabolic syndrome, we measured body mass index (BMI), serum concentrations of high-density lipoprotein-cholesterol, triglycerides, fasting plasma glucose, and blood pressure levels as well as differential leukocyte counts and lymphocyte sub-populations among 439 apparently healthy Japanese men aged 35-60 years. The components of the metabolic syndrome were defined based on the following criteria: BMI >/=25.0 kg/m(2), fasting plasma glucose >/=6.11 mmol/l, systolic blood pressure >/=130 mmHg and/or diastolic blood pressure >/=85 mmHg, high-density lipoprotein (HDL)-cholesterol <1.03 mmol/l, and fasting triglyceride >/=1.69 mmol/l. Counts of total leukocyte, total lymphocyte, CD3 + T cell, CD4 + T cell, and CD4 + CD45RO + T cell significantly correlated with the number of components of the metabolic syndrome (0, 1, 2, and 3+) after adjustment for age and smoking status. These findings were more evident among smokers than among non-smokers. The counts of total leukocytes, total lymphocytes and more specifically memory (CD4 + CD45RO + T) cells were elevated with clustered features of the metabolic syndrome in middle-aged men, which suggest the involvement of altered cellular immune status in the pathogenesis of atherosclerosis.

Adult↗

Job stress, social support, and prevalence of insomnia in a population of Japanese daytime workers.

To clarify the relationship between perceived job stress, social support and prevalence of insomnia in Japanese daytime workers, 1161 male white-collar employees of an electric equipment manufacturing company (age, 23-60 years, mean age of 37.0) were surveyed by means of a mailed questionnaire. Perceived job stress was evaluated with the Japanese version of the generic NIOSH job stress questionnaire. Insomnia was diagnosed if workers had at least 1 of 3 types of symptoms on an almost nightly basis. The symptoms were (1) taking more than 30 min to fall asleep (Difficulty Initiating Sleep, DIS), (2) difficulty in maintaining sleep (DMS), or (3) early morning awakening (EMA). The overall prevalence of insomnia was 23.6% and the prevalences of the three subtypes were 11.3% for DIS, 14.2% for DMS, and 1.9% for EMA. Workers with high intragroup conflict (OR 1.6), high job dissatisfaction (OR 1.5), and high symptoms of depression (OR 2.0) (CES-D > 16) had a significantly increased risk for insomnia after adjusting for multiple confounding factors. Low employment opportunities, physical environment and low coworker support also were weakly associated with risk for insomnia among workers. Furthermore, high depressive symptoms significantly increased the risk of DIS (OR 2.4). Therefore in white-collar male daytime workers, psychological job stress factors such as interpersonal conflicts with fellow employees, job satisfaction, and social support were independently associated with a modestly increased risk of insomnia that included three different subtypes that were considered to be defining for the disorder.

Adult↗

Association of sickness absence with poor sleep and depressive symptoms in shift workers.

A cross-sectional study was conducted to evaluate the contribution of daily sleep habits and depressive symptoms to sickness absences of shift workers. A self-administered questionnaire that solicited answers about sleep, symptoms of depression, sickness absence, diseases/injuries, and lifestyle factors was submitted to a sample of 522 rotating shift workers between the ages of 18-59 (mean 27) yrs of an electric equipment manufacturing company. The seven features of sleep queried were daily hours of sleep, time to fall asleep, awakening during sleep, early morning awakening, sleep well at night, sufficiency of sleep, and excessive daytime sleepiness at work. The responses were assessed over the subject's previous 1-yr period. Each sleep feature, except daily sleeping hours, was dichotomized by the following responses: (1) taking more than 30min to fall asleep (difficulty initiating sleep; DIS), (2) awakening during sleep almost every day (difficulty maintaining sleep; DMS), (3) early morning awakening almost every day (EMA), (4) sleeping very poorly or not so well at night, (5) definite or somewhat insufficient nightly sleep, and (6) excessive daytime sleepiness at work almost every day (EDS). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Sickness absence was calculated by asking subjects "How many days in total have you been absent from work due to sickness, including paid vacation, in the last 1-yr period?" The responses were divided into three groups that included no (0 days) sickness absences (reference group, n=235 subjects), 1 to 4 days (short-term, n=199 subjects), and 5 days or more (long-term, n = 88 subjects). Compared to the prevalence of sleep features of the reference group, workers with short-term absence showed a significantly higher prevalence of EMA with an odds ratio (OR) of 5.3, 95% confidence interval (CI) 1.3-22.0. Long-term absence was significantly associated with DMS (OR = 2.1, 95%CI 1.0-4.6), EMA (OR = 5.6, 95%CI 1.0-28.7), sleeping poorly at night (OR= 2.6, 95%CI 1.4-5.0), and high depressive symptoms (OR = 2.0, 95%CI 1.0-3.7) according to the CES-D score of >16, after adjusting for multiple confounding variables. These data point to an association between both the parameters of poor sleep and symptoms of deep depression when self-reported sickness absence is frequent. The association is particularly strong with long-term absence in male shift workers.

Adolescent↗