Association of CNR1 gene and cannabinoid 1 receptor protein in the human brain.

We aimed to integrate genomic mapping from brain mRNA atlas with the protein expression from positron emission tomography (PET) scans of type 1 cannabinoid (CB1) receptor and to compare the predictive power of CB1 receptor with those of other neuroreceptor/transporters using a meta-analysis. Volume of distribution (VT ) from F18-FMPEP-d2 PET scans, CNR1 gene (Cannabinoid receptor 1) expression, and H3-CP55940 binding were calculated and correlation analysis was performed. Between VT of F18-FMPEP-d2 PET scans and CNR1 mRNA expression, moderate strength of correlation was observed (rho = .5067, p = .0337). Strong positive correlation was also found between CNR1 mRNA expression and H3-CP55940 binding (r = .6336, p = .0364), validating the finding between F18-FMPEP-d2 PET scans and CNR1 mRNA. The correlation between VT of F18-FMPEP-d2 PET scans and H3-CP55940 binding was marginally significant (r = .5025, p = .0563). From the meta-analysis, the correlation coefficient between mRNA expression and protein expressions ranged from -.10 to .99, with a pooled effect of .76. In conclusion, we observed the moderate to strong associations between gene and protein expression for CB1 receptor in the human brain, which was validated by autoradiography. We combined the autoradiographic finding with PET of CB1 receptor, producing the density atlas map of CB1 receptor. From the meta-analysis, the moderate to strong correlation was observed between mRNA expression and protein expressions across multiple genes. Further study is needed to investigate the relationship between multiple genes and in vivo proteins to improve and accelerate drug development.

µ-opioid receptor availability is associated with sex drive in human males.

The endogenous mu-opioid receptor (MOR) system modulates a multitude of social and reward-related functions, and exogenous opiates also influence sex drive in humans and animals. Sex drive shows substantial variation across humans, and it is possible that individual differences in MOR availability underlie interindividual of variation in human sex drive. We measured healthy male subjects' (n = 52) brain's MOR availability with positron emission tomography (PET) using an agonist radioligand, [11C]carfentanil, that has high affinity for MORs. Sex drive was measured using self-reports of engaging in sexual behaviour (sex with partner and masturbating). Bayesian hierarchical regression analysis revealed that sex drive was positively associated with MOR availability in cortical and subcortical areas, notably in caudate nucleus, hippocampus, and cingulate cortices. These results were replicated in full-volume GLM analysis. These widespread effects are in line with high spatial autocorrelation in MOR expression in human brain. Complementary voxel-based morphometry analysis (n = 108) of anatomical MR images provided limited evidence for positive association between sex drive and cortical density in the midcingulate cortex. We conclude that endogenous MOR tone is associated with individual differences in sex drive in human males.

Obesity risk is associated with altered cerebral glucose metabolism and decreased µ-opioid and CB1 receptor availability.

BACKGROUND: Obesity is a pressing public health concern worldwide. Novel pharmacological means are urgently needed to combat the increase of obesity and accompanying type 2 diabetes (T2D). Although fully established obesity is associated with neuromolecular alterations and insulin resistance in the brain, potential obesity-promoting mechanisms in the central nervous system have remained elusive. In this triple-tracer positron emission tomography study, we investigated whether brain insulin signaling, µ-opioid receptors (MORs) and cannabinoid CB1 receptors (CB1Rs) are associated with risk for developing obesity. METHODS: Subjects were 41 young non-obese males with variable obesity risk profiles. Obesity risk was assessed by subjects' physical exercise habits, body mass index and familial risk factors, including parental obesity and T2D. Brain glucose uptake was quantified with [18F]FDG during hyperinsulinemic euglycemic clamp, MORs were quantified with [11C]carfentanil and CB1Rs with [18F]FMPEP-d2. RESULTS: Subjects with higher obesity risk had globally increased insulin-stimulated brain glucose uptake (19 high-risk subjects versus 19 low-risk subjects), and familial obesity risk factors were associated with increased brain glucose uptake (38 subjects) but decreased availability of MORs (41 subjects) and CB1Rs (36 subjects). CONCLUSIONS: These results suggest that the hereditary mechanisms promoting obesity may be partly mediated via insulin, opioid and endocannabinoid messaging systems in the brain.

Brain free fatty acid uptake is elevated in morbid obesity, and is irreversible 6 months after bariatric surgery: A positron emission tomography study.

AIM: To investigate whether there are differences in brain fatty acid uptake (BFAU) between morbidly obese and lean subjects, and the effect of weight loss following bariatric surgery. MATERIALS AND METHODS: We measured BFAU with 14(R, S)-[18 F]fluoro-6-thia-heptadecanoic acid and positron emission tomography in 24 morbidly obese and 14 lean women. Obese subjects were restudied 6 months after bariatric surgery. We also assessed whether there was hypothalamic neuroinflammation in the obese subjects using fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging. RESULTS: Obese subjects had a higher BFAU than lean subjects (1.12 [0.61] vs. 0.72 [0.50] µmol 100 g-1 min-1 , P = 0.0002), driven by higher fatty acid uptake availability. BFAU correlated positively with BMI (P = 0.006, r = 0.48), whole body fatty acid oxidation (P = 0.006, r = 0.47) and leptin levels (P = 0.001, r = 0.54). When BFAU, leptin and body mass index (BMI) were included in the same model, the association between BFAU and leptin was the strongest. BFAU did not correlate with FLAIR-derived estimates of hypothalamic inflammation. Six months after bariatric surgery, obese subjects achieved significant weight loss (-10 units of BMI). BFAU was not significantly changed (1.12 [0.61] vs. 1.09 [0.39] µmol 100 g-1 min-1 , ns), probably because of the ongoing catabolic state. Finally, baseline BFAU predicted worse plasma glucose levels at 2 years of follow-up. CONCLUSIONS: BFAU is increased in morbidly obese compared with lean subjects, and is unchanged 6 months after bariatric surgery. Baseline BFAU predicts worse plasma glucose levels at follow-up, supporting the notion that the brain participates in the control of whole-body homeostasis.

Are there high-risk groups among physicians that are more vulnerable to on-call work?

BACKGROUND: Work done in the emergency departments is one stressful aspect of physicians' work. Numerous previous studies have highlighted the stressfulness of on-call work and especially of night on call. In addition, previous studies suggest that there may be individual differences in adjusting to changes in circadian rhythms and on-call work. OBJECTIVE: The objective of this study was to examine whether physicians' on-call work is associated with perceived work-related stress factors and job resources and whether there are groups that are more vulnerable to on-call work according to sex, age, and specialization status. METHODS: This was a cross-sectional questionnaire study among 3230 Finnish physicians (61.5% women). The analyses were conducted using analyses of covariance adjusted for sex, age, specialization status, and employment sector. RESULTS: Physicians with on-call duties had more time pressure and stress related to team work and patient information systems compared with those who did not have on-call duties. In addition, they had less job control opportunities and experienced organization as less fair and team climate as worse. Older physicians and specialists seemed to be especially vulnerable to on-call work regarding stress factors, whereas younger and specialist trainees seemed vulnerable to on-call work regarding job resources. CONCLUSIONS: Focusing on team issues and resources is important for younger physicians and trainees having on-call duties, whereas for older and specialists, attention should be focused on actual work load and time pressure.

Job demands and job strain as risk factors for employee wellbeing in elderly care: an instrumental-variables analysis.

BACKGROUND: The association between psychosocial work environment and employee wellbeing has repeatedly been shown. However, as environmental evaluations have typically been self-reported, the observed associations may be attributable to reporting bias. METHODS: Applying instrumental-variable regression, we used staffing level (the ratio of staff to residents) as an unconfounded instrument for self-reported job demands and job strain to predict various indicators of wellbeing (perceived stress, psychological distress and sleeping problems) among 1525 registered nurses, practical nurses and nursing assistants working in elderly care wards. RESULTS: In ordinary regression, higher self-reported job demands and job strain were associated with increased risk of perceived stress, psychological distress and sleeping problems. The effect estimates for the associations of these psychosocial factors with perceived stress and psychological distress were greater, but less precisely estimated, in an instrumental-variables analysis which took into account only the variation in self-reported job demands and job strain that was explained by staffing level. No association between psychosocial factors and sleeping problems was observed with the instrumental-variable analysis. CONCLUSIONS: These results support a causal interpretation of high self-reported job demands and job strain being risk factors for employee wellbeing.

Renal Cortical Glucose Uptake Is Decreased in Insulin Resistance and Correlates Inversely With Serum Free-fatty Acids.

CONTEXT: Studies on human renal metabolism are scanty. Nowadays, functional imaging allows the characterization of renal metabolism in a noninvasive manner. We have recently demonstrated that fluorodeoxyglucose F18 (18F FDG) positron emission tomography can be used to analyze renal glucose uptake (GU) rates, and that the renal cortex is an insulin-sensitive tissue. OBJECTIVE: To confirm that renal GU is decreased in people with obesity and to test whether circulating metabolites are related to renal GU. DESIGN, SETTING AND PARTICIPANTS: Eighteen people with obesity and 18 nonobese controls were studied with [18F]FDG positron emission tomography during insulin clamp. Renal scans were obtained ∼60 minutes after [18F]FDG injection. Renal GU was measured using fractional uptake rate and after correcting for residual intratubular [18F]FDG. Circulating metabolites were measured using high-throughput proton nuclear magnetic resonance metabolomics. RESULTS: Cortical GU was higher in healthy nonobese controls compared with people with obesity (4.7 [3.4-5.6] vs 3.1 [2.2-4.3], P = .004, respectively), and it associated positively with the degree of insulin sensitivity (M value) (r = 0.42, P = .01). Moreover, cortical GU was inversely associated with circulating ß-OH-butyrate (r = -0.58, P = .009), acetoacetate (r = -0.48, P = .008), citrate (r = -0.44, P = .01), and free fatty acids (r = -0.68, P < .0001), even when accounting for the M value. On the contrary, medullary GU was not associated with any clinical parameters. CONCLUSION: These data confirm differences in renal cortical GU between people with obesity and healthy nonobese controls. Moreover, the negative correlations between renal cortex GU and free fatty acids, ketone bodies, and citrate are suggestive of substrate competition in the renal cortex.

Insulin-stimulated brain glucose uptake correlates with brain metabolites in severe obesity: A combined neuroimaging study.

The human brain undergoes metabolic adaptations in obesity, but the underlying mechanisms have remained largely unknown. We compared concentrations of often reported brain metabolites measured with magnetic resonance spectroscopy (1H-MRS, 3 T MRI) in the occipital lobe in subjects with obesity and lean controls under different metabolic conditions (fasting, insulin clamp, following weight loss). Brain glucose uptake (BGU) quantified with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)) was also performed in a subset of subjects during clamp. In dataset A, 48 participants were studied during fasting with brain 1H-MRS, while in dataset B 21 participants underwent paired brain 1H-MRS acquisitions under fasting and clamp conditions. In dataset C 16 subjects underwent brain 18F-FDG-PET and 1H-MRS during clamp. In the fasting state, total N-acetylaspartate was lower in subjects with obesity, while brain myo-inositol increased in response to hyperinsulinemia similarly in both lean participants and subjects with obesity. During clamp, BGU correlated positively with brain glutamine/glutamate, total choline, and total creatine levels. Following weight loss, brain creatine levels were increased, whereas increases in other metabolites remained not significant. To conclude, insulin signaling and glucose metabolism are significantly coupled with several of the changes in brain metabolites that occur in obesity.

SGLT2 Inhibitor Dapagliflozin Increases Skeletal Muscle and Brain Fatty Acid Uptake in Individuals With Type 2 Diabetes: A Randomized Double-Blind Placebo-Controlled Positron Emission Tomography Study.

OBJECTIVE: The aim of this study was to investigate the impact of the sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin on tissue fatty acid (FA) uptake in the skeletal muscle, brain, small intestine, and subcutaneous and visceral adipose tissue of individuals with type 2 diabetes by using positron emission tomography (PET). RESEARCH DESIGN AND METHODS: In a 6-week randomized double-blind placebo-controlled trial, 53 patients with type 2 diabetes treated with metformin received either 10 mg dapagliflozin or placebo daily. Tissue FA uptake was quantified at baseline and end of treatment with PET and the long-chain FA analog radiotracer 14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid. Treatment effects were assessed using ANCOVA, and the results are reported as least square means and 95% CIs for the difference between groups. RESULTS: A total of 38 patients (dapagliflozin n = 21; placebo n = 17) completed the study. After 6 weeks, skeletal muscle FA uptake was increased by dapagliflozin compared with placebo (1.0 [0.07, 2.0] µmol ⋅ 100 g-1 ⋅ min-1; P = 0.032), whereas uptake was not significantly changed in the small intestine or visceral or subcutaneous adipose tissue. Dapagliflozin treatment significantly increased whole-brain FA uptake (0.10 [0.02, 0.17] µmol ⋅ 100 g-1 ⋅ min-1; P = 0.01), an effect observed in both gray and white matter regions. CONCLUSIONS: Six weeks of treatment with dapagliflozin increases skeletal muscle and brain FA uptake, partly driven by a rise in free FA availability. This finding is in accordance with previous indirect measurements showing enhanced FA metabolism in response to SGLT2 inhibition and extends the notion of a shift toward increased FA use to muscle and brain.

Lower abdominal adipose tissue cannabinoid type 1 receptor availability in young men with overweight.

OBJECTIVE: Cannabinoid type 1 receptors (CB1R) modulate feeding behavior and energy homeostasis, and the CB1R tone is dysgulated in obesity. This study aimed to investigate CB1R availability in peripheral tissue and brain in young men with overweight versus lean men. METHODS: Healthy males with high (HR, n = 16) or low (LR, n = 20) obesity risk were studied with fluoride 18-labeled FMPEP-d2 positron emission tomography to quantify CB1R availability in abdominal adipose tissue, brown adipose tissue, muscle, and brain. Obesity risk was assessed by BMI, physical exercise habits, and familial obesity risk, including parental overweight, obesity, and type 2 diabetes. To assess insulin sensitivity, fluoro-[18 F]-deoxy-2-D-glucose positron emission tomography during hyperinsulinemic-euglycemic clamp was performed. Serum endocannabinoids were analyzed. RESULTS: CB1R availability in abdominal adipose tissue was lower in the HR than in the LR group, whereas no difference was found in other tissues. CB1R availability of abdominal adipose tissue and brain correlated positively with insulin sensitivity and negatively with unfavorable lipid profile, BMI, body adiposity, and inflammatory markers. Serum arachidonoyl glycerol concentration was associated with lower CB1R availability of the whole brain, unfavorable lipid profile, and higher serum inflammatory markers. CONCLUSIONS: The results suggest endocannabinoid dysregulation already in the preobesity state.

Aerobic Fitness Is Associated with Cerebral µ-Opioid Receptor Activation in Healthy Humans.

INTRODUCTION: Central µ-opioid receptors (MORs) modulate affective responses to physical exercise. Individuals with higher aerobic fitness report greater exercise-induced mood improvements than those with lower fitness, but the link between cardiorespiratory fitness and the MOR system remains unresolved. Here we tested whether maximal oxygen uptake (V̇O2peak) and physical activity level are associated with cerebral MOR availability and whether these phenotypes predict endogenous opioid release after a session of exercise. METHODS: We studied 64 healthy lean men who performed a maximal incremental cycling test for V̇O2peak determination, completed a questionnaire assessing moderate-to-vigorous physical activity (MVPA; in minutes per week), and underwent positron emission tomography with [11C]carfentanil, a specific radioligand for MOR. A subset of 24 subjects underwent additional positron emission tomography scan also after a 1-h session of moderate-intensity exercise and 12 of them also after a bout of high-intensity interval training. RESULTS: Higher self-reported MVPA level predicted greater opioid release after high-intensity interval training, and both V̇O2peak and MVPA level were associated with a larger decrease in cerebral MOR binding after aerobic exercise in the ventral striatum, orbitofrontal cortex, and insula. That is, more trained individuals showed greater opioid release acutely after exercise in brain regions especially relevant for reward and cognitive processing. Fitness was not associated with MOR availability. CONCLUSIONS: We conclude that regular exercise training and higher aerobic fitness may induce neuroadaptation within the MOR system, which might contribute to improved emotional and behavioral responses associated with long-term exercise.

Renal Sinus Fat Is Expanded in Patients with Obesity and/or Hypertension and Reduced by Bariatric Surgery Associated with Hypertension Remission.

Renal sinus fat is a fat depot at the renal hilum. Because of its location around the renal artery, vein, and lymphatic vessels, an expanded renal sinus fat mass may have hemodynamic and renal implications. We studied whether renal sinus fat area (RSF) associates with hypertension and whether following bariatric surgery a decrease in RSF associates with improvement of hypertension. A total of 74 severely obese and 46 lean controls were studied with whole-body magnetic resonance imaging (MRI). A total of 42 obese subjects were re-studied six months after bariatric surgery. RSF was assessed by two independent researchers using sliceOmatic. Glomerular filtration rate (eGFR) was estimated according to the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration). Patients with obesity accumulated more RSF compared to lean controls (2.3 [1.7-3.1] vs. 1.8 [1.4-2.5] cm2, p = 0.03). Patients with hypertension (N = 36) had a larger RSF depot compared to normotensive subjects (2.6 [2.0-3.3] vs. 2.0 [1.4-2.5] cm2, p = 0.0007) also after accounting for body mass index (BMI). In the pooled data, RSF was negatively associated with eGFR (r = -0.20, p = 0.03), whereas there was no association with systolic or diastolic blood pressure. Following bariatric surgery, RSF was reduced (1.6 [1.3-2.3] vs. 2.3 [1.7-3.1] cm2, p = 0.03) along with other markers of adiposity. A total of 9/27 of patients achieved remission from hypertension. The remission was associated with a larger decrease in RSF, compared to patients who remained hypertensive (-0.68 [-0.74 to -0.44] vs. -0.28 [-0.59 to 0] cm2, p = 0.009). The accumulation of RSF seems to be involved in the pathogenesis of hypertension in obesity. Following bariatric surgery, loss of RSF was associated with remission from hypertension.

Obesity risk is associated with brain glucose uptake and insulin resistance.

Objective: To investigate whether alterations in brain glucose uptake (BGU), insulin action in the brain-liver axis and whole-body insulin sensitivity occur in young adults in pre-obese state. Methods: Healthy males with either high risk (HR; n = 19) or low risk (LR; n = 22) for developing obesity were studied with [18F]fluoro-d-glucose ([18F]FDG)-positron emission tomography during hyperinsulinemic-euglycemic clamp. Obesity risk was assessed according to BMI, physical activity and parental overweight/obesity and type 2 diabetes. Brain, skeletal muscle, brown adipose tissue (BAT), visceral adipose tissue (VAT) and abdominal and femoral s.c. adipose tissue (SAT) glucose uptake (GU) rates were measured. Endogenous glucose production (EGP) was calculated by subtracting the exogenous glucose infusion rate from the rate of disappearance of [18F]FDG. BGU was analyzed using statistical parametric mapping, and peripheral tissue activity was determined using Carimas Software imaging processing platform. Results: BGU was higher in the HR vs LR group and correlated inversely with whole-body insulin sensitivity (M value) in the HR group but not in the LR group. Insulin-suppressed EGP did not differ between the groups but correlated positively with BGU in the whole population, and the correlation was driven by the HR group. Skeletal muscle, BAT, VAT, abdominal and femoral SAT GU were lower in the HR group as compared to the LR group. Muscle GU correlated negatively with BGU in the HR group but not in the LR group. Conclusion: Increased BGU, alterations in insulin action in the brain-liver axis and decreased whole-body insulin sensitivity occur early in pre-obese state.

Cerebral µ-opioid and CB1 receptor systems have distinct roles in human feeding behavior.

Eating behavior varies greatly between individuals, but the neurobiological basis of these trait-like differences in feeding remains poorly understood. Central µ-opioid receptors (MOR) and cannabinoid CB1 receptors (CB1R) regulate energy balance via multiple neural pathways, promoting food intake and reward. Because obesity and eating disorders have been associated with alterations in the brain's opioid and endocannabinoid signaling, the variation in MOR and CB1R system function could potentially underlie distinct eating behavior phenotypes. In this retrospective positron emission tomography (PET) study, we analyzed [11C]carfentanil PET scans of MORs from 92 healthy subjects (70 males and 22 females), and [18F]FMPEP-d2 scans of CB1Rs from 35 subjects (all males, all also included in the [11C]carfentanil sample). Eating styles were measured with the Dutch Eating Behavior Questionnaire (DEBQ). We found that lower cerebral MOR availability was associated with increased external eating-individuals with low MORs reported being more likely to eat in response to environment's palatable food cues. CB1R availability was associated with multiple eating behavior traits. We conclude that although MORs and CB1Rs overlap anatomically in brain regions regulating food reward, they have distinct roles in mediating individual feeding patterns. Central MOR system might provide a pharmacological target for reducing individual's excessive cue-reactive eating behavior.

Drug use and pressure ulcers in long-term care units: do nurse time pressure and unfair management increase the prevalence?

AIMS: This study examined the associations between nurse working conditions (time pressure and perceived unfair management) and quality indicators (prevalence of antianxiety or hypnotic drug use and pressure ulcers) in long-term care units. BACKGROUND: Differences persist across long-term care facilities in their care processes and resident outcomes even after adjusting for residents' clinical conditions. Little is known about how nurses' working conditions influence the quality of care. DESIGN: Survey. METHODS: Data on working conditions were drawn in 2002 from 724 nurses in 66 long-term care units that reported quality indicators based on the Resident Assessment Instrument system as measured by Minimum Data Set. Percentage change in the quality indicators from 2002 were estimated using hierarchical multiple regression analyses with adjustments made for the baseline quality indicators (2001) and unit structural factors (unit size and staffing level). RESULTS: Unit time pressure increased the prevalence of both quality problems (p-values <0.05). Perceived unfair management was related to increased drug use (p = 0.038). CONCLUSIONS: The findings of this research suggest that quality of care can be improved by enhancing nurse working conditions. RELEVANCE TO CLINICAL PRACTICE: Organisational initiatives should be aimed at reducing time pressures and promoting fair managerial procedures that engage all nursing staff in the decision-making in long-term care settings.

The moderating effect of employee hostility on the association of long-term elderly care unit's negative resident characteristics to employee stress and well-being.

This study examined the moderating effect of employee hostility on the association of unit-level resident characteristics (depression and behavioral problems) to individual-level employee's resident-related stress and psychological well-being during 1-year follow-up study among 501 employees in elderly care. Our results showed that employee hostility was associated with decreased psychological well-being. In addition, hostility moderated the association between unit-level proportion of depressive residents and resident-related stress experienced by the individual employees. Hostile employees reported increased resident-related stress irrespective of the proportion of depressed residents in the unit. Instead, nonhostile employees were sensitive to the depression in the unit. They reported low levels of stress when depression levels in the unit were low and increased stress when depression levels were high.

Work stressors and the quality of life in long-term care units.

PURPOSE: The purpose of this work was to examine how structural factors, residents' needs for physical and psychosocial assistance, and the work stressors experienced by employees are related to the quality of life of elderly residents in long-term care. DESIGN AND METHODS: Cross-sectional survey data were collected from 1,194 employees and 1,079 relatives of residents in 107 residential-home units and health-center bed wards. Data were analyzed using multilevel modeling. RESULTS: The majority of differences in both employees' and relatives' perceptions of residents' quality of life across units could be explained by work stressors such as time pressure. Large unit size was related to both increased time pressure among employees and reduced quality of life of residents. IMPLICATIONS: Long-term care units are encouraged to review their practices so that employee well-being is supported. Attention also should be focused on unit size, as small units appear better able to help employees cope with work stress, resulting in better quality of life for residents.

Job demands and musculoskeletal symptoms among female geriatric nurses: the moderating role of psychosocial resources.

The present study examined whether job resources (job control, social support, and distributive justice) moderate the associations of high job demands induced by physical and mental workload with musculoskeletal symptoms among geriatric nurses. The data were drawn in Finland from 975 female nurses working in 152 geriatric units who responded to a survey questionnaire. Information on the objective workload in terms of resident characteristics and structural factors was also collected at the unit level. After adjusting for the objective workload, multilevel logistic regression analyses showed that self-reported physical workload was associated with higher risk of musculoskeletal symptoms (OR = 1.93, 95 % CI [1.38, 2.72]) among nurses with low social support. In addition, mental workload was associated with higher risk of musculoskeletal symptoms (OR = 1.72, 95% CI [1.12, 2.62]) for those with low distributive justice. The results suggest that social support and fair reward systems may help to buffer against the detrimental effects of heavy job demands on nurses' musculoskeletal symptoms.

Do nurses who work in a fair organization sleep and perform better and why? Testing potential psychosocial mediators of organizational justice.

We examined whether organizational justice is associated with sleep quality and performance in a population-based sample of 1,729 Finnish registered nurses working full time. In addition, we tested psychological mechanisms mediating the potential association. The results of multivariate linear regression analyses showed higher organizational justice to be associated with fewer sleeping problems (ß values range from -.20 to -.11) and higher self-reported performance (ß values range from .05 to .35). Furthermore, psychological distress (related to the psychological stress model) and job involvement (related to the psychosocial resource model) mediated the association between organizational justice and sleep. Sleeping problems partly mediated the association between organizational justice and performance. Psychological distress explained 51% to 83% and job involvement explained 10% to 15% of the total effects of justice variables on sleeping problems. The findings provide support for the psychological stress model and offer practical implications for reducing nurses' sleeping problems.

Productivity and employees' organizational justice perceptions in long-term care for the elderly.

We examined the associations between productivity, employer characteristics, and context variables, and the organizational justice perceptions of 330 female employees in long-term institutional elderly people care. The productivity measure used was the proportion of the inpatient days to total costs. Employees working in high productivity units experienced higher procedural justice than those working in low productivity units. Hostile employees experienced both the procedures and management as less fair than non-hostile employees. Unit size and resident turnover were negatively and registered nurses percentage positively associated with procedural justice perceptions.