Luenda E. Charles

Area Under the Curve and Other Summary Indicators of Repeated Waking Cortisol Measurements

Objective: To derive the area under the curve and related summary measures of stress from saliva samples collected over time and to provide insight into the interpretation of the derived parameters. In research designed to assess the health consequences of stress these samples are often used as a physiologic indicator of the responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis. To make these repeated measurements of salivary cortisol more useful in defining the relationships between stress and health there is a need to derive two forms of area under the curve that summarize the measurements: area under the curve with respect to ground (AUCG) and area under the curve with respect to increase (AUCI). The latter parameters, AUCI, however, is seldom used by research scientists. Methods: In this study, interpretation and generic definition of the area under the curve was provided through graphical analyses and examination of its association with other summary measures using data from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) Pilot Study. In generic form, AUCI is derived as the area under the curve above the baseline value minus the area above the curve below the baseline value. Results: The sign and magnitude of AUCI are related to the profile and the rate of change of the measurements over time. The parameter showed significant associations with other summary indicators that measure pattern or rate of change of the measurements over time. Conclusion: Principal components analyses revealed that summary parameters derived from repeated cortisol measurements can be grouped into two meaningful general categories: measures of the magnitude of response and measures of the pattern of response over time. AUCG = area under the curve with respect to ground; AUCI = area under the curve with respect to increase; AUCB = area under the curve with respect to baseline; HPA = hypothalamic-pituitary-adrenal; PCA = principal component analyses.

Association of a Dietary Inflammatory Index With Inflammatory Indices and Metabolic Syndrome Among Police Officers

Objectives:To determine whether the dietary inflammatory index (DII) is associated with inflammatory or metabolic biomarkers and metabolic syndrome (MetSyn) among police officers. Methods:Cross-sectional data from the Buffalo Cardio-Metabolic Occupational Police Stress study were derived from saliva and fasting blood samples, anthropometric measurements, long-term shiftwork histories, and demographic, stress/depression, and food frequency questionnaires (FFQs). Metabolic syndrome was defined using standard criteria. Results:Officers in DII quartiles 2 to 4 were more likely to exceed a threshold of 3.0 mg/L for C-reactive protein (odds ratio [OR] = 1.88; 95% confidence interval [95% CI] = 1.02 to 3.45; OR = 2.17; 95% CI = 1.19 to 3.95; OR = 1.57; 95% CI = 0.85 to 2.88, respectively) compared with quartile 1. The glucose intolerance component of MetSyn was more prevalent among officers in DII quartile 4 than among those in quartile 1 (OR = 2.03; 95% CI = 1.08 to 3.82). Conclusions:A pro-inflammatory diet was associated with elevated CRP and with the glucose intolerance component of MetSyn.

Atypical Work Hours and Metabolic Syndrome Among Police Officers

ABSTRACT This study examined whether atypical work hours are associated with metabolic syndrome among a random sample of 98 police officers. Shift work and overtime data from daily payroll records and reported sleep duration were obtained. Metabolic syndrome was defined as elevated waist circumference and triglycerides, low HDL cholesterol, hypertension, and glucose intolerance. Multivariate analysis of variance and analysis of covariance models were used for analyses. Officers working midnight shifts were on average younger and had a slightly higher mean number of metabolic syndrome components. Stratification on sleep duration and overtime revealed significant associations between midnight shifts and the mean number of metabolic syndrome components among officers with less sleep (p = .013) and more overtime (p = .007). Results suggest shorter sleep duration and more overtime combined with midnight shift work may be important contributors to the metabolic syndrome.

Epidemiologic Issues in Study Design and Data Analysis Related to FoodNet Activities

The Foodborne Disease Active Surveillance Network (FoodNet) seeks to determine and to monitor the burden of foodborne diseases in the United States more precisely and to attribute these diseases to specific food vehicles or other exposures. These objectives present statistical and epidemiologic challenges. Estimates of the burden of foodborne diseases should include an estimate of the uncertainty in such calculations. Monitoring the burden of foodborne diseases should account for the expansion of the FoodNet population over time. Attributing foodborne diseases to specific vehicles is facilitated by FoodNet case-control studies of sporadic illness. This article discusses the strengths and limitations of the various studies aimed at addressing these objectives in this supplement. Furthermore, because the FoodNet surveillance areas were not chosen specifically to reflect the demographic composition of the US population, this article also discusses the generalizability of FoodNet results to the US population.

Shift-work and suicide ideation among police officers

BACKGROUND This cross-sectional study assessed the association of shift work with suicide ideation among police officers. METHODS Shift work was based on daily payroll records over 5 years (41 women, 70 men). Standardized psychological measures were employed. ANOVA and Poisson regression were used to evaluate associations. RESULTS Among policewomen with increased depressive symptoms, prevalence of suicide ideation increased by 116% for every 10-unit increase in percentage of hours worked on day shift (prevalence ratio (PR) = 2.16; 95% confidence interval (CI) = 1.22-3.71). Among policemen with higher (but not lower) posttraumatic stress disorder (PTSD) symptoms, prevalence of suicide ideation increased by 13% with every 10-unit increase in the percentage of hours worked on afternoon shift (PR = 1.13; 95% CI = 1.00-1.22). CONCLUSION Prevalence of suicide ideation significantly increased among policewomen with higher depressive symptoms and increasing day shift hours, and among policemen with higher PTSD symptoms with increasing afternoon shift hours.

Prevalence of obesity by occupation among US workers: the National Health Interview Survey 2004-2011.

Objective: To estimate the prevalence of obesity and the change of prevalence of obesity between 2004−2007 and 2008−20011 by occupation among US workers in the National Health Interview Survey. Methods: Self-reported weight and height were collected and used to assess obesity (body mass index ≥ 30 kg/m2). Gender-, race/ethnicity-, and occupation-specific prevalence of obesity were calculated. Results: Prevalence of obesity steadily increased from 2004 through 2008 across gender and race/ethnicity but leveled off from 2008 through 2011. Non-Hispanic black female workers in health care support (49.2%) and transportation/material moving (46.6%) had the highest prevalence of obesity. Prevalence of obesity in relatively low-obesity (white-collar) occupations significantly increased between 2004−2007 and 2008−2011, whereas it did not change significantly in high-obesity (blue-collar) occupations. Conclusions: Workers in all occupational categories are appropriate targets for health promotion and intervention programs to reduce obesity.

Shift work and the incidence of injury among police officers

BACKGROUND Police officers may be injury prone due to fatigue, erratic work hours, and insufficient sleep. This study explored injury incidence among police officers across shifts. METHODS Day-to-day shift data from computerized payroll records (1994-2010) were available from a mid-sized urban police department (n = 430). Sleep duration, shift activity level, returning to work after days off, and injury incidence over time were also examined. RESULTS Age-adjusted incidence rate ratio (IRR) for injury on the midnight shift was 72% larger than the day shift (IRR = 1.72; 95% CI = 1.26-2.36) and 66% larger than the afternoon shift (IRR = 1.66; 95% CI = 1.23-2.25). Injury incidence for the first day back on the midnight shift was 69% larger than day shift (IRR = 1.69; 95% CI = 1.23-2.32) and 54% larger than the afternoon shift (IRR = 1.54; 95% CI = 1.36-1.76). High activity level combined with midnight shift work put officers at increased injury risk (IRR = 2.31; P = 0.0003). Probability of remaining free of injury was significantly higher for day shift than midnight shift (P < 0.0001). CONCLUSIONS Higher injury risk was associated with night shift work in police officers. Night shift combined with high work activity was strongly associated with injury risk. There was a significantly higher probability of not being injured on day compared to midnight or afternoon shifts.

Shift work and sleep: the Buffalo Police health study

Purpose – Working on the night shift is a potential source of occupational stress and has been associated with sleep disorders. The purpose of this paper is to investigate the association between shift work and sleep problems among police officers from Buffalo, New York.Design/methodology/approach – Randomly selected officers (n=111) responded to questions on sleep quality and quantity. Shift work data were obtained from daily payroll records from 1994 to the exam date (1999‐2000). Prevalence ratios (PR) were obtained using Poisson regression models that examined associations of shift work with sleep quality and quantity.Findings – Among police officers, night shift work was significantly and independently associated with snoring and decreased sleep duration.Originality/value – Although the sleep questions were similar to those used in validated sleep questionnaires, a major strength of this study was the availability of daily work history data on all officers for up to five years prior to the current exa...

Post‐traumatic stress symptoms and cortisol patterns among police officers

Purpose – The purpose of the present study is to examine associations between post‐traumatic stress disorder (PTSD) symptoms and salivary cortisol parameters.Design/methodology/approach – PTSD symptoms and cortisol responses were measured in a random sample of 100 police officers. The impact of event scale (IES) categorized into subclinical, mild, moderate and severe levels was employed to measure PTSD symptoms. Cortisol was analyzed from saliva samples over a period of three days and included an awakening response, high protein lunch challenge, whole day (diurnal), and a dexamethasone suppression test (DST).Findings – Officers in moderate and severe PTSD symptom categories had higher mean awakening cortisol values. A significant sample‐time by PTSD interaction (p=0.008) was found for awakening cortisol responses. Officers in the severe PTSD symptom category showed a blunted response to the cortisol protein meal challenge compared to those in lower PTSD categories. Diurnal cortisol levels suggested an inc...

Parental Occupational Exposures and Autism Spectrum Disorder

Both self-report and industrial hygienist (IH) assessed parental occupational information were used in this pilot study in which 174 families (93 children with ASD and 81 unaffected children) enrolled in the Childhood Autism Risks from Genetics and Environment study participated. IH results indicated exposures to lacquer, varnish, and xylene occurred more often in the parents of children with ASD compared to the parents of unaffected children. Parents of children with ASD were more likely to report exposures to asphalt and solvents compared to parents of unaffected children. This study was limited by the small sample size, but results suggest that workplace exposures to some chemicals may be important in the etiology of ASD and deserve further investigation.