Longitudinal and cross-sectional associations between the dietary inflammatory index and objectively and subjectively measured sleep among police officers.

Police officers experience exposures associated with increased inflammation, such as the stress associated with shiftwork and poor-quality diet, both of which have been shown to affect sleep duration and quality. This study examined the longitudinal and cross-sectional effects of the Energy-density Dietary Inflammatory Index (E-DII™) on objectively and subjectively measured sleep among police officers. Data were derived from the Buffalo Cardio-Metabolic Occupational Police Stress Cohort (n = 464 at baseline), with longitudinal data collected from 2004 to 2019. A food frequency questionnaire obtained estimated dietary intake from which E-DII scores were calculated. Dependent variables were objectively (Micro Motion Logger Sleep Watch™) and subjectively (Pittsburgh Sleep Quality Index) measured sleep quality and quantity. The analyses included a series of linear mixed-effects models used to examine cross-sectional and longitudinal associations between the E-DII and sleep quantity and quality. Cross-sectionally, more pro-inflammatory diets were associated with higher wake-after-sleep-onset but improved subjective sleep quality. In models accounting for both longitudinal and cross-sectional effects, for every 1-unit increase in the E-DII scores over time (representing a pro-inflammatory change), wake-after-sleep-onset increased by nearly 1.4 min (p = 0.07). This result was driven by officers who primarily worked day shifts (ß = 3.33, p = 0.01). Conversely, for every 1-unit increase in E-DII score, the Pittsburgh Sleep Quality Index global score improved. More pro-inflammatory diets were associated with increased wake-after-sleep-onset, an objective measure of sleep quality. Intervention studies to reduce dietary inflammatory potential may provide greater magnitude of effect for changes in sleep quality.

Proportionate mortality and national rate of death from COVID-19 among US law enforcement officers: 2020.

Purpose ­: The goal of the present study is to determine the proportionate mortality and national rate of duty-related deaths from COVID-19 among US law enforcement officers during the year 2020. Design/methodology/approach ­: Data for the current study were obtained from the National Law Enforcement Officer Memorial Fund (NLEOMF) database for the year 2020. The database contains deaths designated as caused by incidents that occurred while in the line of duty. The chi-square test and two-sample t-test were used to compare characteristics of officers who died of COVID-19 versus other causes of death. Both the proportionate mortality and rates of death were calculated. To compute the rate of death, the authors obtained data on the total number of law enforcement officers employed in the United States (and therefore at risk) for the year 2020 from Bureau of Labor Statistics. Findings ­: COVID-19 deaths (n = 182) accounted for 62% of all duty-related law enforcement officer deaths during 2020. The national rate of death due to COVID-19 (12.8/100,000 per year) for law enforcement officers was higher compared to all other causes of death combined (8.0/100,000 per year). Research limitations/implications ­: A limitation of the study is the uncertainty of a definitive assessment that the viral infection was acquired through work (versus at home or other non-work-related community settings). Although highly unlikely, deaths designated as duty related entail financial benefits for the survivors and may be a potential source of bias. Given the complexity of personal exposures, the percentage of COVID-19 deaths attributed to duty may represent an over or under estimation of the actual value. Therefore, the data should be interpreted cautiously. Practical implications ­: These findings provide police organizations with information needed to understand the risk of death among officers during the COVID-19 pandemic and to make informed decisions about future preparedness strategies. Originality/value ­: There are presently no published scientific studies that examine both the proportionate mortality and national rate of death from COVID-19 among law enforcement officers for the year 2020.

Shift work and overtime across a career in law enforcement: a 15-year study.

PURPOSE ­: To characterize changes in work hours across a career in law enforcement. DESIGN/METHODOLOGY/APPROACH ­: N = 113 police officers enrolled in the BCOPS cohort were studied. The police officers started their careers in law enforcement between 1994 and 2001 at a mid-sized, unionized police department in northwestern New York and continued to work at this police department for at least 15 years. Day-by-day work history records were obtained from the payroll department. Work hours, leave hours and other pay types were summarized for each calendar year across their first 15 years of employment. Linear mixed-effects models with a random intercept over subject were used to determine if there were significant changes in pay types over time. FINDINGS ­: A total of 1,617 individual-years of data were analyzed. As the police officers gained seniority at the department, they worked fewer hours and fewer night shifts. Total paid hours did not significantly change due to seniority-based increases in vacation time. Night shift work was increasingly in the form of overtime as officers gained seniority. Overtime was more prevalent at the beginning of a career and after a promotion from police officer to detective. ORIGINALITY/VALUE ­: Shiftwork and long work hours have negative effects on sleep and increase the likelihood of on-duty fatigue and performance impairment. The results suggest that there are different points within a career in law enforcement where issues surrounding shiftwork and long work hours may be more prevalent. This has important implications for predicting fatigue, developing effective countermeasures and measuring fatigue-related costs.

Dying for the job: police mortality, 1950-2018.

Purpose ­: This study is a mortality assessment on police officers (68-years, 1950-2018) and includes all causes of death. Design/methodology/approach ­: The authors investigated 1,853 police deaths (1950-2018) using sources of mortality that included the National Death Index, NY State, and available records from the Buffalo NY police department. Standardized Mortality Ratios were calculated. Death codes were obtained from 8th and 9th International Classification of Disease revisions in accordance with the year of death. Findings ­: Compared to the US general population, white male police officers from 1950-2018 had elevated mortality rates for some causes of death, including diseases of the circulatory system, malignant neoplasms, cirrhosis of the liver, and mental disorders. Black and female officers had lower mortality rates for all causes of death compared to the general population. Research limitations/implications ­: The findings of elevated risk for chronic disease among police need to be studied in relation to stress, lifestyle, and exposure to chemical and physical agents. There is a special need to further study officers from minority populations as larger samples become available. Practical implications ­: The results of this study will provide police and occupational health practitioners with objective evidence to determine the health impact of work on law enforcement officers. Originality/value ­: This study is longest running mortality assessment on police officers ever conducted (1950-2018) and includes white, black, and female officers.

Associations of objectively measured sleep characteristics and incident hypertension among police officers: The role of obesity.

This study investigated the associations of baseline sleep onset latency, wake after sleep onset, longest wake episode, number of awakenings, sleep efficiency and sleep duration with incident hypertension during a 7-year follow-up (n = 161, 68% men) and the joint effect of insufficient sleep and obesity on incident hypertension. Sleep parameters were derived from 15-day actigraphy data. Relative risks and 95% confidence intervals were estimated using a robust Poisson regression model. Each 10-min increase in sleep onset latency was associated with an 89% higher risk of hypertension (95% confidence interval [CI] = 1.12-3.20). Each 10-min increase in longest wake episode was associated with a 23% higher risk of hypertension (95% CI = 1.01-1.50) and each 10% decrease in sleep efficiency was associated with a 50% higher risk of hypertension (95% CI = 1.02-2.22). These associations were independent of demographic and lifestyle characteristics, depressive symptoms, shift work, sleep duration and body mass index. Having <6 hr of sleep and a body mass index ≥30 kg/m2 increased the risk of hypertension (relative risk = 2.81; 95% CI = 1.26-6.25) compared with having ≥6 hr of sleep and a body mass index <30 after controlling for confounders. Relative excess risk due to interaction was 3.49 (95% CI = -1.69-8.68) and ratio of relative risk was 3.21 (95% CI = 0.72-14.26). These results suggest that poor sleep quality is a risk factor for hypertension. Longitudinal studies with larger sample sizes are warranted to examine the joint effect of insufficient sleep and obesity on development of hypertension.

Current work hours and coronary artery calcification (CAC): The Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Long work hours may be associated with adverse outcomes, including cardiovascular disease. We investigated cross-sectional associations of current work hours with coronary artery calcification (CAC). METHODS: Participants (n = 3046; 54.6% men) were from the Multi-Ethnic Study of Atherosclerosis. The number of hours worked in all jobs was obtained by questionnaire and CAC from computed tomography. The probability of a positive CAC score was modeled using log-binomial regression. Positive scores were modeled using analysis of covariance and linear regression. RESULTS: Sixteen percent of the sample worked over 50 hours per week. The overall geometric mean CAC score was 5.2 ± 10.0; 40% had positive scores. In fully-adjusted models, prevalence ratios were less than 40 hours: 1.00 (confidence interval [CI]: 0.88-1.12), 40:(ref), 41 to 49:1.13 (CI: 0.99-1.30), and ≥50:1.07 (CI: 0.94-1.23) and longer current work hours were not associated with higher mean CAC scores (<40:56.0 [CI: 47.3-66.3], 40:57.8 [CI: 45.6-73.3], 41 to 49:59.2 [CI: 45.2-77.6], ≥50:51.2 [CI: 40.5-64.8]; P = .686). CONCLUSIONS: Current work hours were not independently associated with CAC scores.

Hidden danger: A 22-years analysis of law enforcement deaths associated with duty-related illnesses (1997-2018).

Purpose ­: Law enforcement is a dangerous profession not only due to assaults, accidents and homicides but also due to health risks. This study examined trends in the national frequency and rate of law enforcement jobrelated illness deaths in the United States over a 22-year period (1997-2018). Design/methodology/approach ­: Data were obtained from the National Law Enforcement Officers Memorial Fund (NLEOMF) on death frequencies related to health issues at work. Death rates were based on the total number of police officers in the United States [rate = (frequency/population at risk) × 100,000]. Trends were examined using standardized regression. Findings ­: A total of 646 deaths were attributed to job-related illness. There was a significant upward trend in overall job-related illness deaths (frequency analyses: ß = 0.88, p < 0.0001; rate analyses: ß = 0.82, p ≤ 0.0001) mainly driven by a significant increase in 911 cancer deaths (frequency analyses: ß = 0.88, p < 0.0001; rate analyses: ß = 0.88, p ≤ 0.0001). Nearly 82 percent of circulatory deaths were from a heart attack, with an average death age of 46.5 years. Research limitations/implications ­: Deaths were not included if they failed to meet medical requirements of the NLEOMF. The data are descriptive, do not estimate risk and should be interpreted cautiously. Practical implications ­: Police wellness programs may help to reduce the danger of deaths associated with job-related illness. Originality/value ­: This is among the first studies to examine frequency and rate of police health-related deaths due to job exposures.

Fatigue and short-term unplanned absences among police officers.

PURPOSE ­: The purpose of this paper is to assess whether shift work, sleep loss and fatigue are related to short-term unplanned absences in policing. DESIGN/METHODOLOGY/APPROACH ­: N = 367 police officers from the Buffalo Police Department were studied. Day-by-day work and sick leave data were obtained from the payroll. Absenteeism was defined as taking a single sick day on a regularly scheduled workday. Biomathematical models of fatigue (BMMF) predicted officers' sleep-wake behaviors and on-duty fatigue and sleepiness. Prior sleep, fatigue and sleepiness were tested as predictors of absenteeism during the next shift. FINDINGS ­: A total of 513,666 shifts and 4,868 cases of absenteeism were studied. The odds of absenteeism increased as on-duty fatigue and sleepiness increased and prior sleep decreased. This was particularly evident for swing shift officers and night shift officers who were predicted by BMMF to obtain less sleep and have greater fatigue and sleepiness than day shift officers. The odds of absenteeism were higher for female officers than male officers; this finding was not due to a differential response to sleep loss, fatigue or sleepiness. PRACTICAL IMPLICATIONS ­: Absenteeism may represent a self-management strategy for fatigue or compensatory behavior to reduced sleep opportunity. Long and irregular work hours that reduce sleep opportunity may be administratively controllable culprits of absenteeism. ORIGINALITY/VALUE ­: Police fatigue has consequences for police officers, departments and communities. BMMF provide a potential tool for predicting and mitigating police fatigue. BMMF were used to investigate the effects of sleep and fatigue on absenteeism.

The CHARGE study: an assessment of parental occupational exposures and autism spectrum disorder.

OBJECTIVES: The aim of this study is to determine if parental occupational exposure to 16 agents is associated with autism spectrum disorder (ASD). METHODS: Demographic, health and parental occupational data were collected as part of the CHildhood Autism Risks from Genetics and Environment study. The workplace exposure assessment was conducted by two experienced industrial hygienists for the parents of 537 children with ASD and 414 typically developing (TD) children. For each job, frequency and intensity of 16 agents were assessed and both binary and semi-quantitative cumulative exposure variables were derived. Logistic regression models were used to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) to assess associations between parental occupational exposures 3 months pre-pregnancy until birth. RESULTS: The OR of ASD in the children of mothers exposed to any solvents was 1.5 times higher than the mothers of TD children (95% CI=1.01-2.23). Cumulative exposure indicated that the OR associated with a moderate level of solvent exposure in mothers was 1.85 (95% CI=1.09, 3.15) for children with ASD compared with TD children. No other exposures were associated with ASD in mothers, fathers or the parents combined. CONCLUSION: Maternal occupational exposure to solvents may increase the risk for ASD. These results are consistent with a growing body of evidence indicating that environmental and occupational exposures may be associated with ASD. Future research should consider specific types of solvents, larger samples and/or different study designs to evaluate other exposures for potential associations with ASD.

Association of occupational stress with waking, diurnal, and bedtime cortisol response in police officers.

OBJECTIVE: Police officers have higher rates of cardiovascular disease (CVD) morbidity and mortality than the U.S. general population. Officers are exposed to conventional and unexpected workplace stressors. The hypothalamic-pituitary-adrenal (HPA) axis plays a major role responding to stressor exposure by releasing cortisol. Prolonged release or excessive levels may result in disease. Our study investigated cross-sectional associations between self-reported work stress and various salivary cortisol parameters. METHODS: A total of 285 police officers (76.5% male) from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) Study (2004-2009) completed the Spielberger Police Stress Survey, reporting frequency and severity of work events during the past month and year to calculate stress indices. Officers provided saliva samples to measure levels of cortisol secretion. Linear regression assessed associations between stress indices and various cortisol parameters, adjusted for age, gender, race/ethnicity, abdominal height, and smoking status. RESULTS: Significant positive associations were observed between stress indices (overall stress, physical danger stress, and past-month lack of support) and diurnal cortisol (AUCg: total area under the curve). Administrative, overall, and physical danger stress in the past year were significantly associated with the diurnal slope. Overall, administrative, and physical danger stress were significantly associated with bedtime levels. There were no significant associations between the stress indices and the awakening cortisol parameters. CONCLUSIONS: Higher stress ratings were related to blunted diurnal decline in cortisol, suggesting conventional and unexpected police stressors may result in HPA axis dysfunction. Future studies investigating possible associations between elevated cortisol and subclinical CVD are needed.

Police stress and depressive symptoms: role of coping and hardiness.

PURPOSE ­: Chronic exposure to occupational stress may lead to depressive symptoms in police officers. The association between police stress and depressive symptoms and the potential influences of coping and hardiness were evaluated. The paper aims to discuss this issue. DESIGN/METHODOLOGY/APPROACH ­: Stress level was assessed in the Buffalo Cardio-Metabolic Occupational Police Stress Study (2004-2009) with the Spielberger Police Stress Survey. The frequency and severity of events at work were used to calculate stress indices for the past year. The Center for Epidemiologic Studies Depression (CES-D) Scale was used to measure depressive symptoms during the past week. Linear regression was used to evaluate the association between the stress indices and depressive symptom scores. Models were adjusted for age, sex, race, smoking status and alcohol intake, and stratified by median values for coping (passive, active and support seeking) and hardiness (control, commitment and challenge) to assess effect modification. FINDINGS ­: Among the 388 officers (73.2 percent men), a significant positive association was observed between total stress and the CES-D score (ß = 1.98 (SE = 0.36); p < 0.001). Lower CES-D scores were observed for officers who reported lower passive coping (ß = 0.94 (SE = 0.45); p = 0.038) and higher active coping (ß = 1.41 (SE = 0.44); p = 0.002), compared with their counterparts. Officers higher in hardiness had lower CES-D scores, particularly for commitment (ß = 0.86 (SE = 0.35); p = 0.016) and control (ß = 1.58 (SE = 0.34); p < 0.001). ORIGINALITY/VALUE ­: Results indicate that high active coping and hardiness modify the effect of work stress in law enforcement, acting to reduce depressive symptoms.

Effort-reward imbalance in police work: associations with the cortisol awakening response.

PURPOSE: We hypothesized that effort-reward imbalance (ERI) is associated with an atypical cortisol response. ERI has been associated with higher job stress. Stress triggers cortisol secretion via the hypothalamic-pituitary-adrenal (HPA) axis, and significant deviation from a typical cortisol pattern can indicate HPA axis dysfunction. METHODS: 176 police officers participated from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) Study. ERI was the exposure variable. Outcome variables were saliva-based peak and mean cortisol values, total area under the curve ground (AUCG) and baseline (AUCI); linear regression line fitted to log-transformed cortisol. Regression analyses were used to examine linear trend between ERI and cortisol parameters. Repeated measures analysis examined whether the pattern of cortisol over time differed between low ERI (< median) and high ERI (≥ median). RESULTS: Mean age was 46 years (SD = 6.6). After adjustment for potential confounders, there was a significant inverse association between ERI and peak cortisol (ß = - 0.20, p = 0.009), average cortisol (ß = - 0.23, p = 0.003), and total area under the curve (ß = - 0.21, p = 0.009). ERI was not significantly associated with AUCI (ß = - 0.11, p = 0.214); slope of the regression line fitted to the cortisol profile (ß = - 0.009, p = 0.908). Repeated measures analyses showed that the cortisol pattern did not vary significantly between high and low ERI using the median as a cut point (interaction p value = 0.790). CONCLUSIONS: ERI was inversely associated with the magnitude of awakening cortisol over time, indicating HPA axis dysregulation and potential future health outcomes.

Social avoidance in policing: Associations with cardiovascular disease and the role of social support.

PURPOSE: The purpose of this paper is to examine the association of social avoidance among police, cardiovascular disease (CVD) (metabolic syndrome (MetSyn)), and social support. DESIGN/METHODOLOGY/APPROACH: Participants were officers from the Buffalo Cardio-Metabolic Occupational Police Stress study (n = 289). Social avoidance (defined as the tendency to avoid social contact) and other subscales from the Cook-Medley Hostility Scale were analyzed. The mean number of MetSyn components across tertiles of the Cook-Medley scales was computed using analysis of variance and analysis of covariance. Social support was measured with the Social Provisions Scale, categorized as high or low based on the median. FINDINGS: The mean number of MetSyn components increased significantly across tertiles of social avoidance (1.51 ± 0.18, 1.52 ± 0.12, and 1.81 ± 0.12); the only Cook-Medley subscale that remained significantly associated with MetSyn following adjustment for age and gender. Participants high in social avoidance reported significantly lower social support (79.9 ± 8.5 vs 85.8 ± 8.6; p = 0.001). RESEARCH LIMITATIONS/IMPLICATIONS: The study is cross-sectional and therefore precludes causality. The authors were unable to determine the direction of associations between social avoidance and MetSyn. The measure of social support was unidimensional, including only perceived support; additional types of social support measures would be helpful. PRACTICAL IMPLICATIONS: This study suggests that occupational-based police social isolation is associated with health outcomes and lower support. Several suggestions are made which will help to improve communication between the police and public. Examples are the use of social media, training in communication techniques, and changing the police role to one of public guardians. ORIGINALITY/VALUE: Social avoidance is the least studied the Cook-Medley subscale associated with CVD. It is important for the health of officers to maintain a social connection with others.

Police work stressors and cardiac vagal control.

OBJECTIVES: This study examines relationships between the frequency and intensity of police work stressors and cardiac vagal control, estimated using the high frequency component of heart rate variability (HRV). METHODS: This is a cross-sectional study of 360 officers from the Buffalo New York Police Department. Police stress was measured using the Spielberger police stress survey, which includes exposure indices created as the product of the self-evaluation of how stressful certain events were and the self-reported frequency with which they occurred. Vagal control was estimated using the high frequency component of resting HRV calculated in units of milliseconds squared and reported in natural log scale. Associations between police work stressors and vagal control were examined using linear regression for significance testing and analysis of covariance for descriptive purposes, stratified by gender, and adjusted for age and race/ethnicity. RESULTS: There were no significant associations between police work stressor exposure indices and vagal control among men. Among women, the inverse associations between the lack of support stressor exposure and vagal control were statistically significant in adjusted models for indices of exposure over the past year (lowest stressor quartile: M = 5.57, 95% CI 5.07 to 6.08, and highest stressor quartile: M = 5.02, 95% CI 4.54 to 5.51, test of association from continuous linear regression of vagal control on lack of support stressor ß = -0.273, P = .04). CONCLUSIONS: This study supports an inverse association between lack of organizational support and vagal control among female but not male police officers.

Police stressors and health: a state-of-the-art review.

PURPOSE ­: The purpose of this paper is to provide a state-of-the-art review on the topic of police stressors and associated health outcomes. Recent empirical research is reviewed in the areas of workplace stress, shift work, traumatic stress, and health. The authors provide a comprehensive table outlining occupational exposures and related health effects in police officers. DESIGN/METHODOLOGY/APPROACH ­: A review of recent empirical research on police stress and untoward psychological and physiological health outcomes in police officers. FINDINGS ­: The results offer a conceptual idea of the empirical associations between stressful workplace exposures and their impact on the mental and physical well-being of officers. RESEARCH LIMITATIONS/IMPLICATIONS ­: A key limitation observed in prior research is the cross-sectional study design; however, this serves as a motivator for researchers to explore these associations utilizing a longitudinal study design that will help determine causality. ORIGINALITY/VALUE ­: This review provides empirical evidence of both mental and physical outcomes associated with police stress and the processes involved in both. Research findings presented in this paper are based on sound psychological and medical evidence among police officers.

High-protein meal challenge reveals the association between the salivary cortisol response and metabolic syndrome in police officers.

OBJECTIVES: Policing is considered a high-stress occupation and officers have elevated cardiovascular morbidity and mortality. To investigate a potential connection, we evaluated the association between salivary cortisol response to a high-protein meal challenge and the metabolic syndrome (MetSyn), a subclinical disorder associated with increased cardiovascular risk. METHODS: Cross-sectional data were from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) Study (2004-2009). MetSyn was defined as having ≥3 components: abdominal obesity, hypertension, elevated triglycerides, reduced high-density lipoprotein cholesterol, and glucose intolerance. Officers provided five saliva samples for cortisol analysis, one before challenge (high-protein shake) and four at 15-min intervals thereafter, where the usual response is increase. Regression models were used to examine trends in mean number of MetSyn components across quartiles of area under the curve (AUC) salivary cortisol. Patterns of mean cortisol response were assessed by MetSyn status using repeated-measures analysis of covariance. RESULTS: Prevalence of MetSyn was 25.7% among 373 officers (74.0% male). The mean count of MetSyn components decreased (1.89, 1.75, 1.55, 1.37; P < 0.01) across increasing quartiles of AUC salivary cortisol. Mean salivary cortisol decreased from baseline (5.55, 4.58, 4.47, 4.79, 4.75 nmol/l) in officers with MetSyn and increased (5.08, 5.82, 5.92, 5.82, 5.60 nmol/l) in their counterparts. The test for interaction between MetSyn status and time of saliva collection was statistically significant (P < 0.001). CONCLUSIONS: Reduced cortisol response to a high-protein meal challenge may be associated with MetSyn. Future longitudinal studies could provide useful evidence for planning intervention studies on cardiovascular risk among police officers.

Shiftwork and decline in endothelial function among police officers.

BACKGROUND: Our objective was to assess the influence of shiftwork on change in endothelial function. METHODS: This longitudinal study was conducted in 188 police officers (78.2% men). Shiftwork status (day, afternoon, night) was assessed objectively using daily Buffalo, NY payroll work history records. Brachial artery flow-mediated dilation (FMD) was assessed using ultrasound. Mean change in FMD% between 2004-2009 and 2010-2015 was compared across shiftwork using analysis of variance/covariance. RESULTS: Overall, mean FMD% decreased from 5.74 ± 2.83 to 3.88 ± 2.11 over an average of 7 years among all officers; P < 0.0001. Effect modification by gender was significant. Among men (but not women), those who worked day shifts had a smaller mean (±SE) decrease in FMD% (-0.89 ± 0.35) compared with those who worked the afternoon (-2.69 ± 0.39; P = 0.001) or night shifts (-2.31 ± 0.45; P = 0.020) after risk factor adjustment. CONCLUSIONS: Larger declines in endothelial function were observed among men who worked afternoon or night shifts. Further investigation is warranted. Am. J. Ind. Med. 59:1001-1008, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Leptin, adiponectin, and heart rate variability among police officers.

OBJECTIVES: Police officers have a high prevalence of cardiovascular disease (CVD). Reduced heart rate variability (HRV) is known to increase CVD risk. Leptin and adiponectin may be related to CVD health. Therefore, our objective was to investigate the relationship between these variables and HRV. METHODS: Leptin and adiponectin levels were measured in 388 officers from the Buffalo Cardio-Metabolic Occupational Police Stress study. HRV was assessed according to methods published by the Task Force of the European Society of Cardiology and the North American Society of Pacing Electrophysiology for measurement and analysis of HRV. Mean values of high-frequency (HF) and low-frequency (LF) HRV were compared across tertiles of leptin and adiponectin using analysis of variance and analysis of covariance; trends were assessed using linear regression models. RESULTS: Leptin, but not adiponectin, was significantly and inversely associated with HRV. Body mass index (BMI) and percent body fat significantly modified the association between leptin and LF (but not HF) HRV. Among officers with BMI < 25 kg/m(2) , leptin was not significantly associated with HRV. However, among officers with BMI ≥ 25 kg/m(2) , leptin was inversely associated with HRV, after adjustment for age, gender, and race/ethnicity; HF HRV, P = 0.019 and LF HRV, P < 0.0001. Similarly, among officers with percent body fat ≥ 25.5%, leptin and LF HRV showed significant, inverse associations (adjusted P = 0.001). CONCLUSIONS: Leptin levels were inversely associated with LF HRV, especially among officers with increased adiposity. Increased leptin levels may be associated with CVD-related health problems.

Alterations in cardiomyocyte function after pulmonary treatment with stainless steel welding fume in rats.

Welding fume is composed of a complex of different metal particulates. Pulmonary exposure to different welding fumes may exert a negative impact on cardiac function, although the underlying mechanisms remain unclear. To explore the effect of welding fumes on cardiac function, Sprague-Dawley rats were exposed by intratracheal instillation to 2 mg/rat of manual metal arc hard surfacing welding fume (MMA-HS) once per week for 7 wk. Control rats received saline. Cardiomyocytes were isolated enzymatically at d 1 and 7 postexposure. Intracellular calcium ([Ca(2+)]i) transients (fluorescence ratio) were measured on the stage of an inverted phase-contrast microscope using a myocyte calcium imaging/cell length system. Phosphorylation levels of cardiac troponin I (cTnI) were determined by Western blot. The levels of nonspecific inflammatory marker C-reactive protein (CRP) and proinflammatory cytokine interleukin-6 (IL-6) in serum were measured by enzyme-linked immunosorbent assay (ELISA). Contraction of isolated cardiomyocytes was significantly reduced at d 1 and d 7 postexposure. Intracellular calcium levels were decreased in response to extracellular calcium stimulation at d 7 postexposure. Changes of intracellular calcium levels after isoprenaline hydrochloride (ISO) stimulation were not markedly different between groups at either time point. Phosphorylation levels of cTnI in the left ventricle were significantly lower at d 1 postexposure. The serum levels of CRP were not markedly different between groups at either time point. Serum levels of IL-6 were not detectable in both groups. Cardiomyocyte alterations observed after welding fume treatment were mainly due to alterations in intracellular calcium handling and phosphorylation levels of cTnI.

The cortisol response in policemen: intraindividual variation, not concentration level, predicts truncal obesity.

OBJECTIVES: Chronic stress, characteristic of police work, affects the hypothalamic-pituitary-adrenal axis' control of cortisol production. Capacity to vary cortisol may be the appropriate measurement to interpret associations with chronic diseases, including obesity, best measured by variability within a person, not central tendency. METHODS: On each of 217 policemen, 18 saliva specimens were obtained for cortisol. Statistical models examined the associations of within-subjects (W-S) cortisol standard deviation (SD) and W-S cortisol mean with waist circumference and four body composition indexes: BMI, and three derived from DEXA: fat-mass, and trunk and extremities lean-mass. Explained variance and the functional nature of associations are reported. RESULTS: Associations of anthropometrics with W-S cortisol mean were not statistically significant at P < 0.05; all associations with W-S cortisol SD were significant. The association of trunk lean mass index (LMIt ) with W-S cortisol SD dominated all models. Associations of W-S cortisol SD with other indexes vanished when models contained LMIt ; when any other index was included in models predicting LMIt , associations with W-S cortisol SD remained significant. The functional association between LMIt and W-S cortisol SD is progressively "hockey stick," monotonic increasing, and flattens at joint high values. CONCLUSIONS: Results support inferences that LMIt measures visceral adiposity and W-S cortisol variability appears to be an appropriate construct to measure in association with visceral adiposity. The "hockey stick" character of the association is consistent with other investigations suggesting obesity is associated with less W-S cortisol variation; however, the monotonic increase and flattening of association at increasing W-ScortisolSD values suggests a more complex association, potentially interpretable by allostasis models of causation.