Associations of burnout with awakening and diurnal cortisol among police officers.

The aim of this cross-sectional study was to assess the associations of burnout with cortisol parameters in 197 police officers from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study (2010-2014). The Maslach Burnout Inventory-General Survey assessed depersonalization, exhaustion, and professional efficacy. Officers provided salivary cortisol samples collected upon awakening, and 15, 30, and 45 min thereafter as well as three additional samples at lunchtime, dinnertime, and bedtime. Total area under the curve with respect to increase (AUCWI for waking and AUCDI for diurnal), total area under the curve with respect to ground (AUCWG for waking and AUCDG for diurnal), and diurnal slope were determined and used in this study. Unadjusted and adjusted (age, sex, and race/ethnicity) associations were examined using linear regression. The mean age of the officers was 48 years and 72% were males. The depersonalization component of burnout was negatively associated with AUCDG (ß = -108.4; p = 0.036). Similarly, as exhaustion increased, AUCWI (ß = -9.58, p = 0.038), AUCDG (ß = -114.7, p = 0.029) and the diurnal slope (ß = -0.000038; p = 0.017) decreased. The Professional efficacy was not associated with any of the cortisol parameters. These results suggest that certain characteristics of burnout may be associated with diminished cortisol secretion in this group of urban police officers. Our findings add to previous studies examining associations of burnout with the cortisol awakening response. Future longitudinal studies are needed to evaluate the temporal relationship between burnout and these cortisol parameters.

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.

Occupational and other risk factors for hand-grip strength: the Honolulu-Asia Aging Study.

BACKGROUND: In certain occupations, including farm work, workers are exposed to hazardous substances, some of which are known to be toxic to the nervous system and may adversely affect muscle strength. Measurement of hand-grip strength may be useful for detecting neurotoxic exposure. METHODS: The authors studied 3522 participants of the Honolulu Heart Program and the Honolulu-Asia Aging Study to determine whether occupational exposures to pesticides, solvents, and metals assessed at exam I (1965-68) are associated with hand-grip strength at exam IV (1991-93) and change in hand-grip strength over 25 years. Correlation, analysis of variance and covariance, and linear regression were used to evaluate the associations. RESULTS: At exam IV, participants ranged in age from 71-93 years; mean hand-grip strength was 39.6 kg at exam I and 30.3 kg at exam IV. Over 25 years, the decline in hand-grip strength was an average of 8-9 kg for all exposures. Hand-grip strength was inversely associated with age and glucose but directly associated with cognitive function, BMI, and haemoglobin level. No other exposures were associated with hand-grip strength. CONCLUSION: This study did not provide evidence that occupational exposure to pesticides, solvents, and metals adversely affected hand-grip strength in this population, but confirmed other important associations with hand-grip strength.