Associations of Sleep Measures with Retinal Microvascular Diameters among Police Officers.

PURPOSE: We examined cross-sectional associations of sleep measures with central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) and investigated whether sex and race/ethnicity modified these associations. METHODS: Participants (N = 202; 78% white; 71% men) were enrolled in the Buffalo Cardio-metabolic Occupational Police Stress study (2011-2014). Wrist actigraphy was used to assess sleep measures including sleep duration, sleep efficiency, sleep onset latency, wake after sleep onset, number of awakenings, and longest wake episode. CRAE and CRVE were obtained from fundus photography of retina and were averaged from both eyes per officer. RESULTS: We observed significant associations between sleep efficiency and CRVE (ß = -2.81 µm; P= .046), and between longest wake episode and CRVE (ß = 3.24 µm; P= .021). Adjustments for demographics, lifestyles, and physical and psychological factors attenuated these associations. Sex modified the independent associations of sleep onset latency and longest wake episode with CRVE. One standard deviation (SD) increase in sleep onset latency was associated with 4.81 µm larger CRVE (P= .028) (P-interaction = 0.098), and one SD increase in longest wake episode was associated with 4.62 µm larger CRVE (P= .032) (P-interaction = 0.115) among men. Race/ethnicity also modified the association between longest wake episode and CRVE (P-interaction = 0.088). A significant association was observed only among white officers (ß = 4.96 µm; P= .025). CONCLUSIONS: We found that poor sleep quality, measured by longest wake episode, was positively and independently associated with retinal venular diameter among white and male officers. Longitudinal studies are warranted to assess whether poor sleep quality is a risk factor for retinal diameter changes.

Influence of Work Characteristics on the Association Between Police Stress and Sleep Quality.

BACKGROUND: Police officers' stress perception, frequency of stressful events (stressors), and police work characteristics may contribute to poor sleep quality through different mechanisms. METHODS: We investigated associations of stress severity (measured by stress rating score) and frequency of stressors with sleep quality and examined the influence of police work characteristics including workload, police rank, prior military experience, and shift work on the associations. Participants were 356 police officers (256 men and 100 women) enrolled in the Buffalo Cardio-Metabolic Occupational Police Stress Study from 2004 to 2009. A mean stress rating score and mean frequency of stressors occurring in the past month were computed for each participant from the Spielberger Police Stress Survey data. Sleep quality was assessed using the global score derived from the Pittsburgh Sleep Quality Index survey. Linear associations of the stress rating score and frequency of stressors with sleep quality (Pittsburgh Sleep Quality Index global score) were tested. Age, sex, race/ethnicity, and smoking status were selected as potential confounders. RESULTS: The stress rating score was positively and independently associated with poor sleep quality (ß = 0.17, p = 0.002). Only workload significantly modified this association (ß = 0.23, p = 0.001 for high workload group; p-interaction = 0.109). The frequency of stressors was positively and independently associated with poor sleep quality (ß = 0.13, p = 0.025). Only police rank significantly modified the association (ß = 0.007, p = 0.004 for detectives/other executives; p-interaction = 0.076). CONCLUSION: Both police officers' perception of stress severity and the frequency of stressors are associated with poor sleep quality. Stress coping or sleep promotion regimens may be more beneficial among police officers reporting high workloads.

Shiftwork and Biomarkers of Subclinical Cardiovascular Disease: The BCOPS Study.

OBJECTIVE: To assess the association of shiftwork with biomarkers of subclinical cardiovascular disease and examine the moderating role of body mass index (BMI) in a police cohort. METHODS: A cross-sectional analysis was conducted among officers who were categorized as working the day, evening, or night shift. Comparisons with inflammatory biomarkers were performed among shifts using analysis of variance/covariance and further stratified by BMI to assess potential effect modification. RESULTS: Associations were observed between day and night shiftworkers for leukocytes, tumor necrosis factor alpha, and homocysteine. After BMI stratification, higher c-reactive protein (CRP) levels were observed among evening shiftworkers with a BMI more than or equal to 30 kg/m versus the day shift. CONCLUSIONS: Future studies examining prospective changes in these markers will allow for more comprehensive evaluation of their association with shiftwork.

Sleep quality and the cortisol awakening response (CAR) among law enforcement officers: The moderating role of leisure time physical activity.

OBJECTIVE: The goal of this study was to investigate the role of leisure time physical activity (LTPA) on the association between sleep quality and the cortisol awakening response (CAR) in people with an occupation that exposes them to high levels of stress. METHODS: Participants were 275 police officers (age = 42 years ± 8.3, 27% women) enrolled in the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study (conducted between 2004 and 2009). Officers provided four salivary cortisol samples (on awakening and 15, 30, and 45 min after awakening). Hours of leisure time physical activity were assessed using the Seven-Day Physical Activity Recall questionnaire. Sleep quality (good/poor) was evaluated using the Pittsburgh Sleep Quality Index (PSQI) scale. Analysis of covariance and repeated measures models were used to examine the association of sleep quality to the two aspects of CAR: cortisol levels (total area under the curve (AUCG), mean, and peak cortisol) and cortisol profiles (the overall pattern in cortisol level during the 45 min period following awakening, the increase in cortisol from baseline to average of post awakening values (mean increase), and area under the curve with respect to increase (AUCI)). Analyses were stratified by participant level of reported LTPA (sufficiently vs. insufficiently active, defined as ≥ 150 vs. < 150 min/week of moderate intensity activity, respectively). Since cortisol activity is known to be influenced by gender, we conducted additional analyses also stratified by gender. RESULTS: Overall, results demonstrated that LTPA significantly moderated the association of sleep quality with CAR. Among participants who were sufficiently active, CAR did not differ by sleep quality. However, in those who were insufficiently active during their leisure time, poor sleep quality was associated with a significantly reduced level of total awakening cortisol secretion (AUCG (a.u.) = 777.4 ±â€¯56 vs. 606.5 ±â€¯45, p = 0.02; mean cortisol (nmol/l) = 16.7 ±â€¯1.2 vs. 13.3 ±â€¯0.9, p = 0.03; peak cortisol (nmol/l) = 24.0 ±â€¯1.8 vs. 18.9 ±â€¯1.5, p = 0.03 for good vs. poor sleep quality, respectively). The normal rise in cortisol after awakening was also significantly lower in inactive officers with poor sleep quality than in those with good sleep quality (mean increase (nmol/l) = 6.7 ±â€¯1.5 vs. 2.3 ±â€¯1.2, p = 0.03; AUCI (a.u.) = 249.3 ±â€¯55 vs. 83.3 ±â€¯44, p = 0.02 for those with good vs. poor sleep quality, respectively). While findings for male officers were consistent with the overall results, CAR did not differ by sleep quality in female officers regardless of LTPA level. CONCLUSION: Findings of this study suggest that poor sleep quality is associated with diminished awakening cortisol levels and dysregulated cortisol patterns over time, but only among officers who were inactive or insufficiently active during their leisure time. In contrast, sleep quality was not associated with any measures of CAR in officers who reported sufficient activity, suggesting a potential protective effect of LTPA. In analyses stratified by gender, findings for male officers were similar to those in the pooled sample, although we found no evidence for a modifying effect of LTPA in women. Future longitudinal studies in a larger population are needed to confirm these findings and further elucidate the relationships between LTPA, sleep quality, and cortisol response.

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.

Separate and Joint Associations of Shift Work and Sleep Quality with Lipids.

BACKGROUND: Shift work and/or sleep quality may affect health. We investigated whether shift work and sleep quality, separately and jointly, were associated with abnormal levels of triglycerides, total cholesterol (TC), and low-and high-density lipoprotein cholesterol in 360 police officers (27.5% women). METHODS: Triglycerides, TC, and high-density lipoprotein were analyzed on the Abbott Architect; low-density lipoprotein was calculated. Shift work was assessed using City of Buffalo payroll work history records. Sleep quality (good, ≤ 5; intermediate, 6-8; poor, ≥ 9) was assessed using the Pittsburgh Sleep Quality Index questionnaire. A shift work + sleep quality variable was created: day plus good sleep; day plus poor sleep; afternoon/night plus good; and poor sleep quality. Mean values of lipid biomarkers were compared across categories of the exposures using analysis of variance/analysis of covariance. RESULTS: Shift work was not significantly associated with lipids. However, as sleep quality worsened, mean levels of triglycerides and TC gradually increased but only among female officers (age- and race-adjusted p = 0.013 and 0.030, respectively). Age significantly modified the association between sleep quality and TC. Among officers ≥ 40 years old, those reporting poor sleep quality had a significantly higher mean level of TC (202.9 ± 3.7 mg/dL) compared with those reporting good sleep quality (190.6 ± 4.0 mg/dL) (gender- and race-adjusted p = 0.010). Female officers who worked the day shift and also reported good sleep quality had the lowest mean level of TC compared with women in the other three categories (p = 0.014). CONCLUSION: Sleep quality and its combined influence with shift work may play a role in the alteration of some lipid measures.

Police Work Absence: An Analysis of Stress and Resiliency.

Police work is a high stress occupation and stress has been implicated in work absence. The present study examined (1) associations between specific types of police stress and work absences, (2) distinctions between "voluntary" (1-day) and "involuntary" (> 3-days) absences; and (3) the modifying effect of resiliency. Officers (n=337) from the Buffalo Cardio-Metabolic Occupational Police Stress study were included in the present study. The sample was 72% male, 77% Caucasian, 73% married, and 75% patrol officers. Mean age was 41 years (SD=6.4). Measures included: the Spielberger Police Stress Survey, 1-year payroll absence data, and the Dispositional Resilience Scale. The negative binomial regression was used to estimate rate ratios (RR) of 1-day and >3-days work absences for increasing stress scores. Models were adjusted for age, race/ethnicity, rank, smoking status, alcohol intake, and sleep duration. For one-unit increase in stress scores, the covariate adjusted RRs for one-day work absences were: total stress score (RR=1.19, 95% CI: 1.04-1.36); administrative stress (RR=1.52, 95% CI: 1.05-2.18); physical/psychological stress (RR=1.54, 95% CI: 1.14-2.07); and lack of support (RR=1.75, 95% CI: 1.01-3.05). Results suggest that officers were more likely to take voluntary 1-day absences due to specific types of stress at work. When the entire sample was considered, there was no significant association between police specific stress and episodes of work absence lasting at least three consecutive days. Hardy individuals, including those with high scores on the challenge sub-score, may use 1-day absences as a positive coping strategy.

Shiftwork and sickness absence among police officers: the BCOPS study.

Shiftwork, regarded as a significant occupational stressor, has become increasingly prevalent across a wide range of occupations. The adverse health outcomes associated with shiftwork are well documented. Shiftwork is an integral part of law enforcement, a high-stress occupation with elevated risks of chronic disease and mortality. Sickness absence is an important source of productivity loss and may also serve as an indirect measure of workers' morbidity. Prior studies of shiftwork and sickness absenteeism have yielded varying results and the association has not been examined specifically among police officers. The objective of this study was to compare the incidence rate of sick leave (any, ≥3 consecutive days) among day-, afternoon-, and night-shift workers in a cohort of police officers and also examine the role of lifestyle factors as potential moderators of the association. Participants (N=464) from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study examined between 2004 and 2009 were used. Daily work history records that included the shift schedule, number of hours worked, and occurrence of sick leave were available for up to 15 yrs starting in 1994 to the date of the BCOPS study examination for each officer. Poisson regression analysis for ungrouped data was used to estimate incidence rates (IRs) of sick leave by shift, and comparison of IRs across shifts were made by computing incidence rate ratios (IRRs) and their 95% confidence intervals (CIs). Sick leave occurred at a higher rate on the night shift (4.37 per 10,000 person-hours) compared with either day (1.55 per 10,000 person-hours) or afternoon (1.96 per 10,000 person-hours) shifts. The association between shiftwork and sickness absence depended on body mass index (BMI). For overweight individuals (BMI≥25 kg/m2), the covariate-adjusted incidence rate of sick leave (≥1 day) was twice as large for night-shift officers compared with those working on the day (IRR=2.29, 95% CI: 1.69-3.10) or afternoon (IRR=1.74, 95% CI: 1.29-2.34) shift. The IR of three or more consecutive days of sick leave was 1.7 times larger for those working on night shift (IRR=1.65, 95% CI: 1.17-2.31) and 1.5 times larger for those working on afternoon shift (IRR=1.50, 95% CI: 1.08-2.08) compared with day shiftworkers. For subjects with normal BMI (<25 kg/m2), the incidence rates of sick leave did not differ significantly across shifts. In conclusion, shiftwork is independently associated with sickness absence, with officers who work the night shift having elevated incidence of sick leave. In addition, overweight officers who work the night shift may be at additional risk for sickness absence.

Antioxidants and pulmonary function among police officers.

OBJECTIVE: To examine associations of dietary antioxidant intake and pulmonary function. METHODS: Antioxidant data (vitamins A, C, D, E, magnesium, and omega-3 fatty acids) were abstracted from food frequency questionnaires. Pulmonary function was measured using American Thoracic Society criteria. We used analysis of variance to investigate associations. RESULTS: Among 79 police officers (57% male), forced vital capacity was positively and significantly associated with vitamin A after adjustment for age, gender, height, race, smoking status, and pack-years of smoking, and with magnesium after adjustment for those risk factors plus total calories, all supplement use, and abdominal height. Among current/former smokers only, mean levels of all pulmonary function measures were significantly associated with vitamin E; smoking status significantly modified these relationships. CONCLUSIONS: Increased intake of vitamin A, vitamin E (among current/former smokers only), and magnesium was associated with better pulmonary function.