Parveen Nedra Joseph

Police work and subclinical atherosclerosis.

Objective: Employment as an urban police officer was hypothesized to be associated with increased structural subclinical cardiovascular disease (CVD), measured by carotid artery intima-media thickness (IMT). Methods: The sample of men and women consisted of police officers (n = 312) and the general population (n = 318), free of clinical CVD. Results: Officers had elevated levels of age-adjusted CVD risk factors (blood pressure, total cholesterol, smoking prevalence) compared with the population sample. In age-, gender-, and traditional risk factor-adjusted models, police officers exhibited increased mean common carotid IMT (police = 0.67 mm, population = 0.64 mm; P = 0.03) and mean maximum carotid IMT (police = 0.99 mm, population = 0.95 mm; P = 0.13). Conclusions: Police officers have increased levels of atherosclerosis compared with a general population sample, which was not fully explained by elevated CVD risk factors; thereby potentially implicating other mechanisms whereby law enforcement work may increase CVD risk.

Cardiovascular reactivity to psychological stress and carotid intima-media thickness in children

The relationship between cardiovascular stress reactivity and carotid artery intima-media thickness (IMT) has been established in adults, but not yet studied in children. Cardiovascular reactivity to an ad lib speech was measured in 20 boys and 20 girls age 11.0 +/- 1.4 years. Measures included heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure reactivity, and mean common carotid artery IMT. Sequential regression analyses were used to establish the incremental increase in R(2) for the prediction of IMT due to cardiovascular reactivity independent of age, socioeconomic status, race, percentage body fat, and baseline BP or HR. SBP reactivity (beta=0.002, , p<.05), but not DBP reactivity (p=.12) or HR reactivity (p=.82), independently predicted carotid artery IMT. This study provides initial evidence that SBP reactivity is associated with IMT and perhaps the early pathogenesis of cardiovascular disease in childhood.

Endothelial function, a biomarker of subclinical cardiovascular disease, in urban police officers.

Objective: Police officers were hypothesized to have decreased endothelial function, measured by brachial artery flow-mediated dilation (FMD). Methods: We compared FMD in police officers (n = 261) and a population sample of men and women (n = 229), all from the same geographical region and free of clinical cardiovascular disease (CVD). Results: Compared with the population sample, police officers had significantly increased age-adjusted CVD risk factors (systolic and diastolic blood pressure, total cholesterol, smoking prevalence, and alcohol consumption). Police officers exhibited lower mean FMD after adjustment for age, gender, and traditional CVD risk factors among those aged 55 years or younger (%dilation: police = 5.49%, population = 6.49%; P = 0.04). Conclusions: Police officers exhibited decreased endothelial function (lower FMD) compared with the civilian sample, which was not fully explained by traditional CVD risk factors, suggesting that other pathways may contribute to increased CVD risk in law enforcement work.

Associations of Objectively Measured and Self-Reported Sleep Duration With Carotid Artery Intima Media Thickness Among Police Officers

BACKGROUND We aimed to examine the association of objectively measured and self-reported sleep duration with carotid artery intima media thickness (IMT) among 257 police officers, a group at high risk for cardiovascular disease (CVD). METHODS Sleep duration was estimated using actigraphic data and through self-reports. The mean maximum IMT was the average of the largest 12 values scanned bilaterally from three angles of the near and far wall of the common carotid, bulb, and internal carotid artery. Linear and quadratic regression models were used to assess the association of sleep duration with IMT. RESULTS Officers who had fewer than 5 or 8 hr or more of objectively measured sleep duration had significantly higher maximum IMT values, independent of age. Self-reported sleep duration was not associated with either IMT measure. CONCLUSION Attainment of sufficient sleep duration may be considered as a possible strategy for atherosclerosis prevention among police officers.

Examining the Brachial Artery Reactivity Curve Measured by B-Mode Ultrasound in the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) Pilot Study

Brachial artery reactivity was assessed in the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) Pilot Study using B-mode ultrasound. Carotid artery intima-media thickness (CIMT), a known subclinical predictor of cardiovascular disease, also was examined in relation to brachial artery reactivity. A continuous scan was performed on the artery for 8 min (1 min of baseline, 4 min of cuff inflation at 40 mmHg greater than systolic pressure, 3 min after cuff release). The sample for analysis (n = 78; 43 men, 35 women) consisted of active-duty police officers from a larger sample in the BCOPS pilot study. Means and standard deviations (SDs) stratified by gender were calculated, along with Pearsons correlations between brachial variables, and with CIMT. Arterial diameters (baseline, pre-cuff release, peak) were significantly different (p < 0.001) between men and women. Peak arterial dilation occurred at 50.77 ± 21.97 sec (49.67 ± 20.22 cardiac cycles) after cuff deflation in men, and 44.66 ± 24.07 sec (44.57 ± 20.36 cardiac cycles) after cuff deflation in women. Mean common carotid artery IMT and mean maximum IMT of all carotid sites were significantly correlated (p < 0.01) in men (r = 0.691) and women (r = 0.450). Brachial reactivity measures were inversely correlated with CIMT in women, and in contrast, positively correlated in men.

Associations of Depressive Symptoms and Brachial Artery Reactivity among Police Officers.

Objectives Mental health has been shown to be linked with certain underlying physiological mechanisms. The objective of this cross sectional study was to investigate the relationship between depressive symptoms and brachial artery reactivity (BAR) in an understudied population: police officers. Methods Participants were 351 police officers who were clinically examined in the Buffalo Cardio-Metabolic Police Stress (BCOPS) study. BAR was performed using standard B-Mode ultrasound procedures. Depressive symptoms were measured using the Center for Epidemiological Studies Depression (CES-D) scale. Mean values of the difference between the baseline and maximum diameters of the brachial artery were determined across three categories of CES-D score using the analysis of variance and the analysis of covariance. p-values for linear trends were obtained from linear regression models. Results The mean age (± standard deviation) of all officers was 40.9 ± 7.2 years. Women had a slightly higher mean CES-D score than men (8.9 ± 8.9 vs. 7.4 ± 6.4) and a slightly higher percentage increase of BAR than men (6.90 vs. 5.26%). Smoking status significantly modified the associations between depressive symptoms and BAR. Among current smokers, mean absolute values of BAR significantly decreased as depressive symptoms increased after adjustment for age, gender, race/ethnicity, hypertension, and diabetes; the multivariate-adjusted p-values were 0.033 (absolute) and 0.040 (%). Associations between depressive symptoms and BAR were not statistically significant among former smokers or never smokers. Conclusion Depressive symptoms were inversely associated with BAR among police officers who were current smokers and together may be considered a risk factor for cardiovascular disease among police officers. Further prospective research is warranted.

Central Adiposity and Subclinical Cardiovascular Disease in Police Officers

Given the associations between obesity and cardiovascular disease (CVD), we evaluated a related but less well-established association between waist circumference and brachial artery reactivity (BAR), a functional measurement of subclinical CVD, where lower levels indicate dysfunction. Regression models examined trends in mean BAR across waist circumference tertiles in police officers, a high-stress occupational group with increased risk for CVD. Mean BAR decreased across increasing waist tertiles among men, but not women, and this association was stronger among officers who consumed more alcohol. Larger waist circumference may be associated with lower BAR, providing an opportunity for intervention prior to disease development.

Estimation of the maximum flow-mediated brachial artery response using local regression methods

We consider methods for estimating the maximum from a sequence of measurements of flow-mediated diameter of the brachial artery. Flow-mediated vasodilation (FMD) is represented using the maximum change from a baseline diameter measurement after the release of a blood pressure cuff that has been inflated to reduce flow in the brachial artery. The influence of the measurement error on the maximum diameter from raw data can lead to overestimation of the average maximum change from the baseline for a sample of individuals. Nonparametric regression models provide a potential means for dealing with this problem. When using this approach, it is necessary to make a judicious choice of regression methods and smoothing parameters to avoid overestimation or underestimation of FMD. This study presents results from simulation studies using kernel-based local linear regression methods that characterize the relationship between the measurement error, smoothing and bias in estimates of FMD. Comparisons between fixed or constant smoothing and automated smoothing parameter selection using the generalized cross validation (GCV) statistic are made, and it is shown that GCV-optimized smoothing may over-smooth or under-smooth depending on the heart rate, measurement error and measurement frequency. We also present an example using measured data from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) pilot study. In this example, smoothing resulted in lower estimates of FMD and there was no clear evidence of an optimal smoothing level. The choice to use smoothing and the appropriate smoothing level to use may depend on the application.