Association of shift work with mood disorders and sleep problems according to chronotype: a 17-year cohort study

Both evening chronotype and shift work are associated with depressive symptoms. This study examined whether the association between shift work and mood disorders and sleep problems varies by chronotype. The study population included 10637 participants from the Finnish Hospital Personnel Cohort Study. Work schedule was assessed using repeated questionnaires between 2000 and 2017. Chronotype, assessed using a single item from the Diurnal Type Scale, was categorized into definite morning, somewhat morning, somewhat evening, and definite evening types. The presence of mood disorders was identified by the 12-item General Health Questionnaire. Sleep problems were assessed by self-reported frequency of difficulty falling asleep and maintaining asleep. Longitudinal fixed effects models were used to examine the associations between shift work and the presence of mood disorders and sleep problems, stratified by chronotype. We found that fixed night work was associated with mood disorders among somewhat evening (adjusted odds ratio [OR] 1.91, 95% CI 1.09-3.34) and definite evening-type workers (adjusted OR 2.05, 95% CI 1.06-3.98). Shift work with night shifts was associated with mood disorders among definite evening-type workers (adjusted OR 1.75, 95% CI 1.18-2.60). Similarly, fixed night work was associated with difficulty maintaining sleep only among evening-type workers. In conclusion, evening chronotype increase the vulnerability to mood disorders and sleep disturbances related to night work

Validity of self-reported exposure to shift work

OBJECTIVE: To evaluate the validity of widely used questionnaire items on work schedule using objective registry data as reference. METHOD: A cohort study of hospital employees who responded to a self-administered questionnaire on work schedule in 2008, 2012 and 2014 and were linked to individual-level pay-roll-based records on work shifts. For predictive validity, leisure-time fatigue was assessed. RESULTS: According to the survey data in 2014 (n=8896), 55% of the day workers had at least 1 year of earlier shift work experience. 8% of the night shift workers changed to day work during the follow-up. Using pay-roll data as reference, questions on ‘shift work with night shifts’ and ‘permanent night work’ showed high sensitivity (96% and 90%) and specificity (92% and 97%). Self-reported ‘regular day work’ showed moderate sensitivity (73%), but high specificity (99%) and ‘shift work without night shifts’ showed low sensitivity (62%) and moderate specificity (87%). In multivariate logistic regression analysis, the age-adjusted, sex-adjusted and baseline fatigue-adjusted association between ‘shift work without night shifts’ and leisure-time fatigue was lower for self-reported compared with objective assessment (1.30, 95% CI 0.94 to 1.82, n=1707 vs 1.89, 95% CI 1.06 to 3.39, n=1627). In contrast, shift work with night shifts, compared with permanent day work, was similarly associated with fatigue in the two assessments (2.04, 95% CI 1.62 to 2.57, n=2311 vs 1.82, 95% CI 1.28 to 2.58, n=1804). CONCLUSIONS: The validity of self-reported assessment of shift work varies between work schedules. Exposure misclassification in self-reported data may contribute to bias towards the null in shift work without night shifts

Self-reported reasons for on-duty sleepiness among commercial airline pilots

Experimental and epidemiological research has shown that human sleepiness is determined especially by the circadian and homeostatic processes. The present field study examined which work-related factors airline pilots perceive as causing on-duty sleepiness during short-haul and long-haul flights. In addition, the association between the perceived reasons for sleepiness and actual sleepiness levels was examined, as well as the association between reporting inadequate sleep causing sleepiness and actual sleep-wake history. The study sample consisted of 29 long-haul (LH) pilots, 28 short-haul (SH) pilots, and 29 mixed fleet pilots (flying both SH and LH flights), each of whom participated in a 2-month field measurement period, yielding a total of 765 SH and 494 LH flight duty periods (FDPs) for analyses (FDP, a period between the start of a duty and the end of the last flight of that duty). The self-reports of sleepiness inducers were collected at the end of each FDP by an electronic select menu. On-duty sleepiness was rated at each flight phase by the Karolinska Sleepiness Scale (KSS). The sleep-wake data was collected by a diary and actigraph. The results showed that "FDP timing" and "inadequate sleep" were the most frequently reported reasons for on-duty sleepiness out of the seven options provided, regardless of FDP type (SH, LH). Reporting these reasons significantly increased the odds of increased on-duty sleepiness (KSS >= 7), except for reporting "inadequate sleep" during LH FDPs. Reporting "inadequate sleep" was also associated with increased odds of a reduced sleep-wake ratio (total sleep time/amount of wakefulnessPeer reviewe

Extracting Urban Morphology for Atmospheric Modeling from Multispectral and SAR Satellite Imagery

This paper presents an approach designed to derive an urban morphology map from satellite data while aiming to minimize the cost of data and user interference. The approach will help to provide updates to the current morphological databases around the world. The proposed urban morphology maps consist of two layers: 1) Digital Elevation Model (DEM) and 2) land cover map. Sentinel-2 data was used to create a land cover map, which was realized through image classification using optical range indices calculated from image data. For the purpose of atmospheric modeling, the most important classes are water and vegetation areas. The rest of the area includes bare soil and built-up areas among others, and they were merged into one class in the end. The classification result was validated with ground truth data collected both from field measurements and aerial imagery. The overall classification accuracy for the three classes is 91 %. TanDEM-X data was processed into two DEMs with different grid sizes using interferometric SAR processing. The resulting DEM has a RMSE of 3.2 meters compared to a high resolution DEM, which was estimated through 20 control points in flat areas. Comparing the derived DEM with the ground truth DEM from airborne LIDAR data, it can be seen that the street canyons, that are of high importance for urban atmospheric modeling are not detectable in the TanDEM-X DEM. However, the derived DEM is suitable for a class of urban atmospheric models. Based on the numerical modeling needs for regional atmospheric pollutant dispersion studies, the generated files enable the extraction of relevant parametrizations, such as Urban Canopy Parameters (UCP).Peer reviewe

Effects of overstory tree density, site preparation, and ground vegetation on natural Scots pine seedling emergence and survival in northern boreal pine forests

Natural regeneration is a commonly used forest regeneration method in northern Finland. It is not known, however, what would be the optimal overstory density and ground vegetation composition for seedling emergence and survival, and if site preparation is needed to accompany overstory density manipulation. We studied the effects of overstory density (unthinned control and thinning to 50,150, and 250 trees.ha(-1)) and ground vegetation removal (mechanical site preparation with disc trenching) on the number of naturally germinated pine seedlings and survival of individual seedlings over a period of 8 to 11 years. Bare mineral soil was a superior seedbed compared to intact vegetation cover, even though the mortality rate was high on mineral soil. Greater cover of lingonberry, crowberry, and slash had a negative effect on seedling number. Seedling mortality was initially high (60% died during the first 2 years) but decreased throughout the first 5 years. The survival rate of seedlings located in the mineral soil of the upper part of the disc trencher track was twice as high as that of seedlings located in the lower part of the track. High coverage of hair mosses (Polytrichum spp.) was associated with poorer seedling survival. An overstory density of 50-150 trees.ha(-1) with site preparation seems to be an efficient treatment to promote regeneration under these circumstances

Objective working hour characteristics and work-life conflict among hospital employees in the Finnish public sector study

This epidemiological cohort study, based on Finnish public sector data, investigated the associations between objective working hour characteristics and work-life conflict in day and shift work. The comprehensive data of hospital workers (n = 8 931, 92% women, average age 45 years), consisted of survey responses from 2012, linked with the payroll data of working hour characteristics from 91 days preceding the survey. Logistic regression analysis was used to investigate the associations between working hour characteristics and experiencing work-life conflict often/very often. The analyses were adjusted for age (50 years), sex, level of education, marital status, number of small (0-6 years) and school-aged (7-18 years) children, and the overall stressfulness of the life situation. We also conducted stratified analyses of age and sex on the basis of significant interactions. Difficulties in combining work and life were more often associated with shift work without night shifts and shift work with night shifts than with day work (41% and 34 versus 27%; OR for shift work with night shifts 1.78, 95% CI 1.59-2.00, OR for shift work without night shifts 1.42, 95% CI 1.26-1.60). A high proportion (> 25%) of long (> 40h, (OR 1.26, 95% 1.14-1.39) and very long (> 48h, OR 1.31, 95% CI 1.15-1.49) weekly working hours were associated with work-life conflict, and in the stratified analysis, the latter was also true among women (OR 1.54, 95% CI 1.25-1.89). Of the unsocial working hour characteristics, a relatively large amount (> 10% of all shifts) of evening (OR 1.56, 95% CI 1.41-1.72) and night shifts (OR 1.46, 95%CI 1.32-1.61), a high proportion (> 25% of all shifts) of quick returns ( 25% of all days off) was associated with work-life conflict among men (OR 1.90, 95% CI 1.11-3.25), but not in the whole sample. When the two types of shift work were analyzed separately, shift work without night shifts and very long work weeks had higher odds (OR 1.47, 95% CI 1.20-1.80) of work-life conflict than shift work with night shifts. Conversely, weekend work and evening shifts had higher odds of work-life conflict among shift workers with night shifts (OR 1.74, 95% 1.55-1.96; (OR 1.57, 95% CI 1.40-1.77) than among those without night shifts. To conclude, this study shows that shift workers with and without night shifts more often have difficulties combining work and life than day workers. Several unsocial working hour characteristics, including long work weeks, evening and night shifts, weekend work, and quick returns, are associated with work-life conflict

Shift work with and without night work as a risk factor for fatigue and changes in sleep length: A cohort study with linkage to records on daily working hours

We examined shift work with or without night work as a risk factor for fatigue and short or long sleep. In a prospective cohort study with 4- and 6-year follow-ups (the Finnish Public Sector study), we linked survey responses of 3,679 full-time hospital employees on sleep duration and fatigue to records on daily working hours in 2008 (baseline), 2012 and 2014. We used logistic regression to estimate risk ratios and their confidence intervals to examine whether continuous exposure to shift work or changes between shift work and day work were associated with short (≤6.5 hr) or long (≥9.0 hr) sleep over 24 hr and fatigue at work and during free days. Compared with continuous day work and adjusting for age, gender, education and fatigue/sleep duration at baseline, continuous shift work with night shifts was associated with increased fatigue during free days (risk ratio = 1.38, 95% confidence interval 1.17-1.63) and long sleep (risk ratio = 8.04, 95% confidence interval 2.88-22.5, without adjustment for education) after 6-year follow-up. Exposure to shift work without night shifts increased only long sleep after 6 years (risk ratio = 5.87, 95% confidence interval 1.94-17.8). A change from day work to shift work with or without night shifts was associated with an increased risk for long sleep, and a change from shift work to day work with a decreased risk for long sleep and fatigue. This study suggests that irregular shift work is a modifiable risk factor for long sleep and increased fatigue, probably reflecting a higher need for recovery

Intravenous levosimendan-norepinephrine combination during off-pump coronary artery bypass grafting in a hemodialysis patient with severe myocardial dysfunction

This the case of a 63 year-old man with end-stage renal disease (on chronic hemodialysis), unstable angina and significantly impaired myocardial contractility with low left ventricular ejection fraction, who underwent off-pump one vessel coronary bypass surgery. Combined continuous levosimendan and norepinephrine infusion (at 0.07 μg/kg/min and 0.05 μg/kg/min respectively) started immediately after anesthesia induction and continued for 24 hours. The levosimendan/norepinephrine combination helped maintain an appropriate hemodynamic profile, thereby contributing to uneventful completion of surgery and postoperative hemodynamic stability. Although levosimendan is considered contraindicated in ESRD patients, this case report suggests that combined perioperative levosimendan/norepinephrine administration can be useful in carefully selected hemodialysis patients with impaired myocardial contractility and ongoing myocardial ischemia, who undergo off-pump myocardial revascularization surgery

Environmental Stress Affects DNA Methylation of a CpG Rich Promoter Region of Serotonin Transporter Gene in a Nurse Cohort

Peer reviewe

Association of changes in work shifts and shift intensity with change in fatigue and disturbed sleep: a within-subject study

Objectives The aim of this study was to examine whether changes in work shifts and shift intensity are related to changes in difficulties to fall asleep, fatigue, and sleep length.Methods Questionnaire responses of hospital employees (N=7727, 93% women) in 2008, 2012, 2014 and 2015 were linked to daily-based records of working hours during three months preceding each survey. We used conditional logistic regression and longitudinal fixed-effects analyses to investigate odds ratios (OR) and 95% confidence intervals (CI) for each 25% within-individual change in the proportion of working hour characteristics in relation to changes in fatigue, difficulties to fall asleep, and 24-hour sleep length.Results Change in night but not in morning or evening shifts was associated with parallel changes in odds for longer sleep length (OR 1.45, 95% CI 1.28-1.64) and fatigue during free days (OR 1.38, 95% CI 1.16-1.64). Similarly, short shift intervals and having >2 but not >4 consecutive night shifts were associated with increased odds of fatigue during work and difficulties to fall asleep (OR 1.42, 95% CI 1.19-1.72 and OR 1.10, 95% CI 1.05-1.19, respectively). Among workers aged >= 50 years, the associations were the strongest between night shifts and longer sleep (OR 2.24,95% CI 1.52-3.81) and between higher proportion of short shift intervals and fatigue during free days (OR 1.68, 95% CI 1.10-2.54).Conclusions Among shift workers with fatigue or sleep problems, decreasing the proportion of night shifts and quick returns and giving preference to quickly forward-rotating shift systems may reduce fatigue