Effects of Choir Singing on Mental Health: Results of an Online Cross-sectional Study.

OBJECTIVES: The study aims to quantify the impact of sociodemographic, personal, and choir-related characteristics on perceived singing well-being and mental health changes due to singing. STUDY DESIGN: 847 German adult choristers (233m, 614f, age 18-86 years) were interviewed in a cross-sectional online questionnaire study that included questions on singing well-being, vocal and choral characteristics, the adapted versions of the Bochum change questionnaire (BCQ2000), the Utrecht Work Engagement Scale (UWES-09), and the WHO-5 well-being index. METHODS: Multiple regression models were calculated with singing related well-being or mental health changes as dependent variables and individual and choir-related characteristics as factors. Predictors of mental health benefits were analyzed in gender subgroups and in persons with a low or normal/high score on the WHO-5. RESULTS: On average, participants rated the impact of singing on well-being and mental health changes positively. Subgroup analysis revealed smaller but significant positive mental health effects in men compared to women and in persons with a low WHO-5 score compared to those with a normal/high score. Education level and relationship status were not significantly related to subjects' perceptions of mental health benefits, whereas singing well-being increased with age in women and in participants with a low WHO-5 score. Larger improvements in mental health came along with longer choir membership, more singing hours per week, and a high engagement in choral activity. Significant positive associations of well-being with optimal singing behavior and vocal warm-ups were observed. CONCLUSION: Results suggest that singers of all ages, genders, and educational backgrounds perceive the choral experience as beneficial to their well-being and mental health. Positive effects are related to WHO-5 scores, engagement in choral activity, and optimal singing conditions. On average, women rate singing benefits higher than men and singers with preexisting vocal pathologies or low WHO-5 benefit slightly less.

No Gender Differences in Pain Perception and Medication after Lumbar Spine Sequestrectomy-A Reanalysis of a Randomized Controlled Clinical Trial.

BACKGROUND: Gender issues have received increasing attention in clinical research of the past years, and biological sex has been introduced as a moderating variable in experimental pain perception. However, in clinical studies of acute pain and gender, there are conflicting results. In particular, there are limited data on the impact of gender differences after spinal sequestrectomy. The aim of this work is to examine gender differences in postoperative pain and pain medication consumption in an inpatient clinical setting. METHODS: Data of a completed double-blind RCT was subdivided by gender and reanalyzed by means of an analysis of variance in repeated measures. Outcomes included pain severity measured on a VAS, affective (SES-A) and sensory pain perception (SES-S) and morphine equivalent doses (MED) of analgesics after spinal sequestrectomy. RESULTS: In total, 42 female (47.73%) and 46 male (52.27%) patients were analyzed. No differences in pain severity (VAS: Gender × Time F = 0.35; (df = 2, 86); p = 0.708), affective and sensory pain perception (SES-A: Gender × Time F = 0.08; (df = 2, 86); p = 0.919; SES-S: Gender × Time F = 0.06; (df = 2, 86); p = 0.939) or post-operative opioid use between men and women (MEDs: Gender × Time F = 1.44; (df = 2, 86); p = 0.227) could be observed. CONCLUSIONS: This reanalysis of an RCT with respect to gender differences is to our knowledge the first attempt to investigate the role of gender in pain perception and medication after lumbar spine sequestrectomy. In contrast to other studies, we were not able to show significant differences between male and female patients in all pain-related outcomes. Apart from well-established pain management, psychological reasons such as gender-specific response biases or the observer effect might explain our results. TRIAL REGISTRATION: The study was registered as a regulatory phase IV study at the German Clinical Trials Register (DRKS), an open-access online register for clinical trials conducted in Germany (Reg-No: DRKS00007913).

Hypericum perforatum to Improve Postoperative Pain Outcome After Monosegmental Spinal Sequestrectomy (HYPOS): Results of a Randomized, Double-Blind, Placebo-Controlled Trial.

Introduction: Patients undergoing lumbar spine surgery often suffer from severe radicular postoperative pain leading to the prescription of high-dose opioids. In Integrative Medicine, Hypericum perforatum is known as a remedy to relieve pain caused by nerve damage. Objectives: This trial investigated whether homeopathic Hypericum leads to a reduction in postoperative pain and a decrease in pain medication compared with placebo. Design: Randomized double blind, monocentric, placebo controlled clinical trial. Settings/Location: Department of Neurosurgery, Community Hospital Herdecke. Subjects: Inpatients undergoing lumbar sequestrectomy surgery. Interventions: Homeopathic treatment versus placebo in addition to usual pain management. Outcomes Measures: Primary endpoint was pain relief measured with a visual analog scale. Secondary endpoints were the reduction of inpatient postoperative analgesic medication and change in sensory and affective pain perception. Results: Baseline characteristics were comparable between the groups. Pain perception between baseline and day 3 did not significantly differ between the study arms. With respect to pain medication, total morphine equivalent doses did not differ significantly. However, a statistical trend and a moderate effect (d = 0.432) in the decrease of pain medication consumption in favor of the Hypericum group was observed. Conclusion: This is the first trial of homeopathy that evaluated the efficacy of Hypericum C200 after lumbar monosegmental spinal sequestrectomy. Although no significant differences between the groups could be shown, we found that patients who took potentiated Hypericum in addition to usual pain management showed lower consumption of analgesics. Further investigations, especially with regard to pain medication, should follow to better classify the described analgesic reduction. Clinical Trial Registration Number: German Clinical Trials Register No: DRKS00007913.

Yoga, Eurythmy Therapy and Standard Physiotherapy (YES-Trial) for Patients With Chronic Non-specific Low Back Pain: A Three-Armed Randomized Controlled Trial.

We aimed to evaluate the effects of yoga and eurythmy therapy compared to conventional physiotherapy exercises in patients with chronic low back pain. In a three-armed, multicentre, randomized controlled trial, patients with chronic low back pain were treated for 8 weeks in group sessions (75 minutes once per week). Primary outcome was patients' physical disability (measured by RMDQ) from baseline to week 8. Secondary outcome variables were pain intensity and pain-related bothersomeness (VAS), health-related quality of life (SF-12) and life satisfaction (BMLSS). Outcomes were assessed at baseline, after the intervention at 8 weeks and at a 16-week follow up. Data of 274 participants were used for statistical analyses. There were no significant differences between the three groups for the primary and all secondary outcomes. In all groups, RMDQ decreased comparably at 8 weeks, but did not reach clinical meaningfulness. Pain intensity and pain-related bothersomeness decreased, while quality of life increased in all 3 groups. In explorative general linear models for the SF-12's mental health component participants in the eurythmy arm benefitted significantly more compared to physiotherapy and yoga. Furthermore, within-group analyses showed improvements of SF-12 mental score for yoga and eurythmy therapy only. All interventions were safe. Clinical Trials Register: DRKS-ID: DRKS00004651 Perspective: This article presents the results of a multicentre three-armed randomized controlled trial on the clinical effects of three 8-week programs in patients with chronic low back pain. Compared to the 'gold standard' of conventional physiotherapeutic exercises, eurythmy therapy and yoga therapy lead to comparable symptomatic improvements in patients with chronic low back pain. However, the within-group effect sizes were small to moderate and did not reach clinical meaningfulness on patients' physical disability (RMDQ).

The prevalence of young carers - a standardised survey amongst school students (KiFam-study).

BACKGROUND: Children and adolescents who provide care, assistance or support for a chronically ill family member are called young carers. While there is a growing body of research about their specific situation, needs and impact of caring, only very few studies provide information on prevalence rates. OBJECTIVES: The aim was to provide prevalence data for young carers in Germany, and to describe and quantify the nature and extent of their help. DESIGN: A cross-sectional study. SETTINGS: Data collection took place between 2016 and 2017 in 44 secondary schools (fifth to 13th grade) in North Rhine-Westphalia, Germany. PARTICIPANTS: A total of 6313 students aged from 10 to 22 years participated in this study. They represent 0.5% of the basic population. METHODS: Based on the results of a preliminary qualitative study, a standardised electronic questionnaire was developed, which comprised four subject areas: socio-demographic information, general daily aids, health-related quality of life and chronic illness within the family. Statistical analyses included chi-square tests for nominal data and univariate analyses of variance for metrical data together with 95% confidence intervals. RESULTS: 19.6% (n = 1238) of all respondents state that someone in their family needs help due to a chronic illness. Nevertheless, not all of them are involved in caring activities. The prevalence of those defined as young carers in this study is 6.1% (n = 383), 64% are girls. They take on a wide range of activities. In addition to domestic work, they help their ill relatives with mobility, dressing and undressing, medication, feeding, personal hygiene and with intimate care. CONCLUSIONS: The data provide a good insight into the situation of young carers. The prevalence rate is higher than expected. It refers to the social relevance of this topic and the need for further investigations.

The Digital Tree Drawing Test for Screening of Early Dementia: An Explorative Study Comparing Healthy Controls, Patients with Mild Cognitive Impairment, and Patients with Early Dementia of the Alzheimer Type.

The digital tree drawing test (dTDT) is a newly developed screening tool for the early detection of Alzheimer's disease. It is performed with a digitizing pen, recording each pen stroke with temporal and spatial precision. It was hypothesized that movement characteristics recorded during the painting process contribute to the identification of patients with mild cognitive impairment (MCI) and early dementia of the Alzheimer type (eDAT). The study population consisted of 187 participants (67 healthy controls, 64 MCI, and 56 eDAT patients) with a mean age of 68.6±10.6 years. Between-group comparisons of the dTDT-variables were conducted with analysis of variance. The diagnostic power of dTDT variables was analyzed with stepwise logistic regressions and areas under curve (AUC) of receiver operating control curves. Cognitively impaired persons used less colors and line widths and changed them less often than healthy subjects (p-values ≤0.05). Compared to control, eDAT patients had larger not-painting periods, were slower, and their pictures had less contrast, image size, and complexity (p-values ≤0.01). Logistic regression models of stepwise selected dTDT variables resulted in an AUC of 0.84 (95% confidence interval (CI) [0.79, 0.90], sensitivity = 0.78, specificity = 0.77) for discriminating healthy subjects from all cognitive impaired, an AUC of 0.77. (95% CI [0.69; 0.85], sensitivity = 0.56, specificity = 0.83) for discriminating healthy controls from MCI patients and an AUC of 0.90 (95% CI [0.84, 0.96], sensitivity = 0.86, specificity = 0.82) for discriminating controls from eDAT patients. The results suggest that digital recording of pen-stroke data during the drawing process can contribute to the screening of cognitive impaired patients.

Diagnostic value of digital clock drawing test in comparison with CERAD neuropsychological battery total score for discrimination of patients in the early course of Alzheimer's disease from healthy individuals.

The early detection of cognitive impairment or dementia is in the focus of current research as the amount of cognitively impaired individuals will rise intensely in the next decades due to aging population worldwide. Currently available diagnostic tools to detect mild cognitive impairment (MCI) or dementia are time-consuming, invasive or expensive and not suitable for wide application as required by the high number of people at risk. Thus, a fast, simple and sensitive test is urgently needed to enable an accurate detection of people with cognitive dysfunction and dementia in the earlier stages to initiate specific diagnostic and therapeutic interventions. We examined digital Clock Drawing Test (dCDT) kinematics for their clinical utility in differentiating patients with amnestic MCI (aMCI) or mild Alzheimer's dementia (mAD) from healthy controls (HCs) and compared it with the diagnostic value of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery total score. Data of 381 participants (138 patients with aMCI, 106 patients with mAD and 137 HCs) was analyzed in the present study. All participants performed the clock drawing test (CDT) on a tablet computer and underwent the CERAD test battery and depression screening. CERAD total scores were calculated by subtest summation, excluding MMSE scores. All tablet variables (i.e. time in air, time on surface, total time, velocity, pressure, pressure/velocity relation, strokes per minute, time not painting, pen-up stroke length, pen-up/pen-down relation, and CDT score) during dCDT performance were entered in a forward stepwise logistic regression model to assess, which parameters best discriminated between aMCI or mAD and HC. Receiver operating characteristics (ROC) curves were constructed to visualize the specificity in relation to the sensitivity of dCDT variables against CERAD total scores in categorizing the diagnostic groups. dCDT variables provided a slightly better diagnostic accuracy of 81.5% for discrimination of aMCI from HCs than using CERAD total score (accuracy 77.5%). In aMCI patients with normal CDT scores, both dCDT (accuracy 78.0%) and CERAD total scores (accuracy 76.0%) were equally accurate in discriminating against HCs. Finally, in differentiating patients with mAD from healthy individuals, accuracy of both dCDT (93.0%) and CERAD total scores (92.3%) was excellent. Our findings suggest that dCDT is a suitable screening tool to identify early cognitive dysfunction. Its performance is comparable with the time-consuming established psychometric measure (CERAD test battery).

Early Detection of Alzheimer's Disease Based on the Patient's Creative Drawing Process: First Results with a Novel Neuropsychological Testing Method.

Based on the knowledge of art therapy, we developed a new neuropsychological drawing test in order to identify individuals with mild cognitive impairment (MCI) as well as dementia patients and healthy controls (HC). By observing a variety of drawing characteristics of 92 participants with a mean age of 67.7, art therapy and dementia experts discriminate HC from MCI, early dementia of the Alzheimer-type (eDAT), and moderate dementia of the Alzheimer-type (mDAT) by the process analysis of tree drawings on a digitizing tablet. The art therapist's average categorical rating of healthy and MCI or demented individuals matched the clinical diagnosis by 88%. In a first small study, we analyzed interrater reliability, sensitivity, specificity, negative and positive predicted values of our tree drawing test (TDT) in comparison with the clock drawing test (CDT). Similar values of moderate interrater reliability were found for the TDT (0.56) as well as for the CDT (0.54). A significant high sensitivity of 0.9 within this binary impairment scale (HC versus impaired or demented) can be demonstrated. Substantial values for the specificity (0.67) could be obtained that however remain under a perfect value of the CDT (1.0). Considering 31 individuals that received the clinical diagnosis "impaired or demented" the TDT shows a higher recognition rate for the MCI group than the CDT. Furthermore in 8 of 12 borderline cases of clinical diagnosis, the outcome of the TDT diagnosis was consistent with the final clinical result.

The Effectiveness of Leech Therapy in Chronic Low Back Pain.

BACKGROUND: Leech therapy has been found to be effective in the treatment of a number of chronic musculoskeletal pain syndromes. Leeches are also often used empirically to treat chronic low back pain, but data from clinical trials have been lacking to date. We therefore conducted the first randomized trial of leech therapy for chronic low back pain. METHODS: Patients with chronic low back pain were randomized to receive either a single session of local treatment with 4-7 leeches or four weekly sessions of exercise therapy (1 hour each) led by a physical therapist. The primary endpoint was a change in average back pain intensity, as measured using a 100-mm visual analog scale (VAS), after 28 days. Secondary end- points included functional impairment (Roland-Morris Disability Questionnaire, Hannover Functional Ability Questionnaire), quality of life (Short-Form Health Questionnaire [SF 36]), pain perception (pain perception scale = Schmerzempfindungsskala [SES]), depressivity (Center for Epidemiological Studies Depression Scale [CES-D]), and analgesic consumption (questionnaire/ diary). Trial visits took place before treatment and on days 28 ± 3 and 56 ± 5 after the start of treatment; the overall duration of the trial was 56 ± 5 days. RESULTS: The mean low back pain score improved from 61.2 ± 15.6 before treatment to 33.1 ± 22.4 on day 28 in the leech ther- apy group (n = 25) and from 61.6 ± 14.8 to 59.8 ± 16.7 in the exercise therapy group (n = 19) (group difference -25.2; 95% con- fidence interval [-41.0; -9.45]; p = 0.0018). Significant benefits of leech therapy were also found at both time points with respect to physical impairment and function as well as physical quality of life. The patients' expectations from treatment were higher in the leech therapy group but did not significantly affect the findings. CONCLUSION: A single session of leech therapy is more effective over the short term in lowering the intensity of pain over the short term and in improving physical function and quality of life over the intermediate term (4 weeks and 8 weeks, respectively). The limitations of this trial are the lack of blinding and the small number of patients. Leech therapy appears to be an effective treat- ment for chronic low back pain.

Soluble chemokine (C-X-C motif) ligand 16 (CXCL16) in urine as a novel biomarker candidate to identify high grade and muscle invasive urothelial carcinomas.

Information on biomarkers of urothelial carcinomas (UC) for clinical decision-making is limited. Here, we newly identified and verified CXCL16 as a promising novel biomarker in urine for high grade and muscle invasive UC in a cross-sectional cohort of 308 UC patients, 126 urological hospital controls, and 50 population controls using antibody arrays and ELISA. Median CXCL16 levels in urine was significantly higher in UC patients (273.2 pg/mg creatinine) compared to hospital (148.1 pg/mg) and population controls (85.1 pg/mg) with a particular preference for high grade (460.8 pg/mg), muscle invasive (535.7 pg/mg) and primary UC (327.8 pg/mg) (all p<0.0001). Group differences were confirmed after adjusting or stratifying for potential clinical and individual characteristics, such as leukocyte counts, haematuria, age, gender, and smoking status. In contrast, CXCL16 showed less discriminating power in low grade (244.3 pg/mg), non-muscle invasive (≤pT1, 251.2 pg/mg) and recurrent UC (203.9 pg/mg). In agreement with its function in immune defence, expression of CXCL16 in tissue samples of primary UC patients (n=53) showed only a weak or no immunoreactivity compared to urological hospital controls (n=32). Expression of CXCR6, the G-protein-coupled receptor of CXCL16, remained unchanged. Our findings suggest that evading the immune defence by shedding cell-surface CXCL16 and its increased elimination in urine is a molecular feature of high grade and muscle invasive UC. Therefore, urinary CXCL16 may serve as a useful, simple and non-invasive tool to identify high-risk UC with increased risk of progression at the molecular level.

Occupational Exposure to Manganese and Fine Motor Skills in Elderly Men: Results from the Heinz Nixdorf Recall Study.

OBJECTIVES: Exposure to manganese (Mn) may cause movement disorders, but less is known whether the effects persist after the termination of exposure. This study investigated the association between former exposure to Mn and fine motor deficits in elderly men from an industrial area with steel production. METHODS: Data on the occupational history and fine motor tests were obtained from the second follow-up of the prospective Heinz Nixdorf Recall Study (2011-2014). The study population included 1232 men (median age 68 years). Mn in blood (MnB) was determined in archived samples (2000-2003). The association between Mn exposure (working as welder or in other at-risk occupations, cumulative exposure to inhalable Mn, MnB) with various motor functions (errors in line tracing, steadiness, or aiming and tapping hits) was investigated with Poisson and logistic regression, adjusted for iron status and other covariates. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated for substantially impaired dexterity (errors >90th percentile, tapping hits <10th percentile). RESULTS: The median of cumulative exposure to inhalable Mn was 58 µg m-3 years in 322 men who ever worked in at-risk occupations. Although we observed a partly better motor performance of exposed workers at group level, we found fewer tapping hits in men with cumulative Mn exposure >184.8 µg m-3 years (OR 2.15, 95% CI 1.17-3.94). MnB ≥ 15 µg l-1, serum ferritin ≥ 400 µg l-1, and gamma-glutamyl transferase ≥74 U l-1 were associated with a greater number of errors in line tracing. CONCLUSIONS: We found evidence that exposure to inhalable Mn may carry a risk for dexterity deficits. Whether these deficits can be exclusively attributed to Mn remains to be elucidated, as airborne Mn is strongly correlated with iron in metal fumes, and high ferritin was also associated with errors in line tracing. Furthermore, hand training effects must be taken into account when testing for fine motor skills.

Use of the Bovine Udder Skin model to evaluate the tolerability of Mesem cosmetic cream.

Observational studies of Mesem cream (based on Mesembryanthemum crystallinum L. plant extract) found that it had positive effects on skin hydration and smoothing of the skin. However, some patients reported skin irritation effects. The current study evaluated the skin tolerability of Mesem cream, as compared to the carrier cream (without the active ingredient), by using the isolated perfused bovine udder skin model. The primary outcomes investigated were cytotoxicity (i.e. cell viability), assessed with the MTT assay, and irritancy and inflammation, assessed by measuring PGE2 tissue levels. A total reaction score was calculated by combining the results for each parameter. In the case of a single topical application, significant differences were found between the carrier cream and the Mesem cream. While the application of carrier cream resulted in low cytotoxicity (-8.4% change in viability, as compared to the untreated control), the Mesem cream was more cytotoxic (-18.7% change). In addition, one hour after application, PGE2 levels were higher in Mesem cream-treated skin, as compared to carrier cream-treated skin (16.6% versus 11.3%). Further experiments (tape-stripped skin and repeated application) also found significant differences between the two creams in the results obtained. Evaluation of the effectiveness, safety and tolerability of phyto-cosmetic products is important. Our results confirmed the findings of two previous human observational studies (the human patch test and open application study). Future experiments to understand the underlying principles of its effectiveness, safety and tolerability should include extracts of M. crystallinum L. juice, as well as the Mesem cream itself.

The risk of bias in systematic reviews tool showed fair reliability and good construct validity.

OBJECTIVE: There is a movement from generic quality checklists toward a more domain-based approach in critical appraisal tools. This study aimed to report on a first experience with the newly developed risk of bias in systematic reviews (ROBIS) tool and compare it with A Measurement Tool to Assess Systematic Reviews (AMSTAR), that is, the most common used tool to assess methodological quality of systematic reviews while assessing validity, reliability, and applicability. STUDY DESIGN AND SETTING: Validation study with four reviewers based on 16 systematic reviews in the field of occupational health. RESULTS: Interrater reliability (IRR) of all four raters was highest for domain 2 (Fleiss' kappa κ = 0.56) and lowest for domain 4 (κ = 0.04). For ROBIS, median IRR was κ = 0.52 (range 0.13-0.88) for the experienced pair of raters compared to κ = 0.32 (range 0.12-0.76) for the less experienced pair of raters. The percentage of "yes" scores of each review of ROBIS ratings was strongly correlated with the AMSTAR ratings (rs = 0.76; P = 0.01). CONCLUSION: ROBIS has fair reliability and good construct validity to assess the risk of bias in systematic reviews. More validation studies are needed to investigate reliability and applicability, in particular.

Associations between former exposure to manganese and olfaction in an elderly population: Results from the Heinz Nixdorf Recall Study.

Occupational exposure to manganese (Mn) has been associated with impairments in olfaction and motor functions, but it has yet to be determined if such effects persist upon cessation of exposure. The objective of this study was to evaluate the influence of former occupational Mn exposure on olfaction within the framework of a prospective cohort study among an elderly German population. Information on job tasks with recognized Mn exposure and data on odor identification assessed with Sniffin' sticks was collected during the second follow-up of the Heinz Nixdorf Recall Study. The study population consisted of 1385 men aged 55-86 years, 354 of whom ever worked in jobs with potential Mn exposure (median 58.3µg/m3 years, interquartile range 19.0-185µg/m3 years). Multiple exposure measures, including job tasks, cumulative Mn exposure, and Mn determined in blood samples (MnB) archived at baseline, were used to estimate effects of Mn on olfaction. Having ever worked as welder was associated with better olfaction compared to other blue-collar workers without Mn exposure. Blue-collar workers identified less odors in comparison to white-collar workers. Concentrations of previous Mn exposure >185µg/m3 years or MnB ≥15µg/L were not associated with impaired olfaction. In addition to a strong age effect, participants with lower occupational qualification identified less odors. We found no relevant association of former Mn exposure at relatively low levels with impaired olfaction. Possible neurotoxic Mn effects may not be persistent after cessation.

Cortisol awakening response: are sampling delays of 15 minutes acceptable?

Cortisol awakening responses (CAR) are often blunted or even extinguished when saliva samplings are delayed. The literature suggests that delays of 10 or 15 min are tolerable. Delays of 15 min were analysed with 510 CARs with the first sample taken within 3 min post-awakening followed by 4 samples taken 15, 30, 45, and 60 min later. Varying delays of up to 30 min were analysed with these and further 148 CARs where sampling began within 30 min post-awakening. Times of awakening and of saliva collection were verified by polysomnography or actimetry and by electronic devices respectively. Simulated sampling delays of 15 min revealed highly significant deviations from correctly taken CARs. No deviations were found for delays of up to 11.5 min suggesting that delays of up to 10 min are acceptable but that delays between 10 and 15 min might become critical.

The normalization of the cortisol awakening response and of the cortisol shift profile across consecutive night shifts--an experimental study.

This study tested the hypothesis that the cortisol awakening response (CAR) and the cortisol shift profile normalize with successive night shifts due to the shift of the circadian system. 18 students (9 women, 9 men, 19-29 years), worked first four consecutive morning- and then four consecutive night shifts. Each work shift was preceded by an 8-h sleep opportunity meaning that the sleep-activity cycle was advanced by 8 h. The advance of the circadian system was promoted by a 2-h bright light pulse at the end of each night shift and quantified by 24-h phase assessment procedures (PA) before and after the four day shifts and again after the four night shifts. Saliva samples were taken 0, 15, 30, 45, and 60 min post-awakening, hourly during each work shift and each PA. During the night shift sequence, the CAR, indicated by the area under curve with respect to increase (AUC(I)), increased gradually across the 4-day sleep periods. Baseline levels were reached after 3 days in men and 4 days in women. The increase of the CAR was associated with a gradually increasing decline of cortisol levels during the night shifts. This adjustment was--at least not only--related to the advance of the circadian system which was 5 h. A contributor to the increase of the CAR might be the anticipation of the upcoming demands of the following work shifts.

Experimental studies on the effects of nocturnal noise on cortisol awakening response.

Cortisol awakening response (CAR), a considerable increase in cortisol concentrations post-awakening, is considered a reliable indicator of the reactivity of the hypothalamus-pituitary-adrenal axis (HPA). As noise has been shown to activate the HPA-axis, this analysis focuses on CAR as a possible indicator of noise-induced sleep disturbances. This analysis focuses on CAR using two studies. In Study 1, six women and six men (18-26 years) slept for 13 nights each in the laboratory. They were exposed to the noises of three different trains, each with 20, 40 or 80 pass-bys, with equivalent noise levels varying between 44 and 58 dBA, on nine nights. In Study 2, 23 persons slept first for four nights and then four days, in the laboratory; finally 23 persons slept in the reverse order. During six sleep periods, they were randomly exposed to road or rail traffic noises with L Aeq varying between 42 and 56 dBA. To determine the CAR, salivary cortisol concentrations were ascertained in both studies after night sleep immediately after awakening, and 15 and 45 minutes later; in Study 2 also after 30 and 60 minutes later. The time of awakening was determined using the polysomnogram and the participants rated their subjective sleep quality every morning. Subjective sleep quality was rated worse after noisy when compared to quiet nights. CAR was, however, attenuated only after the noisiest nights in a subgroup of Study 2. These persons had just performed a sequence of four consecutive night shifts. They were obviously still in the process of re-adjustment to their usual day-oriented schedule and probably in a state of elevated vulnerability. The study concludes that nocturnal noise exposure affects the CAR only if a person is in a state of at least temporarily elevated vulnerability.

Alterations of the cortisol quiescent period after experimental night work with enforced adaptation by bright light and its relation to morningness.

A previous study where the delay of the circadian system was induced by bright light that was adjusted to the individual melatonin onset revealed concomitant alterations of the cortisol quiescent period that correlated inversely with morningness. This meta-analysis focuses on the question whether this applies to experimental shift work with fixed light schedules. The analysis bases on data from three laboratory studies where healthy young men [18 evening-, 20 neither-, 11 morning types (MT)] performed three consecutive day shifts and then three consecutive night shifts. Phase assessment procedures were performed after every three shifts to ascertain the diurnal melatonin profile for the quantification of the phase shift and the diurnal cortisol profile for the determination of the cortisol quiescent period. Work was done in 150-200 lx but phase delays were promoted by bright light (1,500-2,000 lx) either by 4-h pulses in the first part of the night or by continuous exposure during the whole night shifts. These different light scenarios caused similar phase delays. Morningness was inversely related to the phase delay and to the alteration of the cortisol quiescent period. The latter became shorter in morning and longer in evening types. Thus, MT are disadvantaged, even if treated with bright light. This suggests that morning-oriented career shift workers might have a higher health risk. These results need to be replicated by directed studies and verified by epidemiological studies.

Blink rate during tests of executive performance after nocturnal traffic noise.

This analysis is on the hypothesis that nocturnal traffic noise affects sleep quality whereas performance decrement is avoided by increased effort expressed by a decrease in blink rates (BRs) during a visual task. Twenty-four persons (12 women, 12 men; 19-28 years, 23.56+/-2.49 years) slept during three consecutive weeks in the laboratory while exposed to road, rail, or aircraft noise with weekly permuted changes. Each week consisted of a random sequence of a quiet night (32 dBA) and three nights with equivalent noise levels of 39, 44 and 50 dBA respectively. The polysomnogram was recorded during all nights. Every morning the participants rated their sleep quality and then completed two executive tasks (Go/Nogo-, Switch-task). Neither of the two performance tests was affected by nocturnal noise. Sleep efficiency and subjective sleep quality decreased with increasing noise levels but were not associated with the type of noise. In contrast, BRs were associated with the type of noise, not with noise levels. The results do not support the hypothesis concerning the BR. The possible reasons are discussed. However, the results do not exclude that other physiological parameters such as heart rate or brain potentials measured during the tests might have revealed alterations associated with nocturnal noise exposure.

The cortisol awakening response: a pilot study on the effects of shift work, morningness and sleep duration.

This study concerned the possible influence of experimental shift work, morningness and sleep length on the cortisol awakening response (CAR). Eight morning-oriented (MT) and eight evening-oriented (ET) healthy young men (19-27 years) slept after three consecutive day shifts during the night and after three consecutive night shifts during the day in the laboratory. Salivary cortisol concentrations were ascertained after each sleep period upon awakening and half an hour later, half-hourly during work shifts, and hourly during two 24-h periods, after the three day shift/night sleep sequences and after the three night shift/day sleep sequences. Statistical analyses considered the temporal position of sleep (night, day), the succession of sleep periods, the diurnal type and the polysomnographically verified total sleep time. The CAR was significantly smaller after day than after night sleep and increased significantly with total sleep time in ET. MT had moderately higher cortisol concentrations upon awakening than ET probably because they wake up at a later time of their circadian rhythm. But neither the CARs nor the cortisol concentrations during the following work shifts or during the 24h profiles were different in both diurnal types. The cortisol concentrations during work shifts correlated significantly with the previous post-awakening concentrations in MT but not in ET. Due to the small samples further studies are needed.