Cortisol patterns and brachial artery reactivity in a high stress environment.

Chronic stress can result in frequent or persistent challenges of the hypothalamic-pituitary-adrenal (HPA) axis resulting in abnormal cortisol patterns and increased risk for cardiovascular disease (CVD). Police work is an environment replete with stress. The present article describes associations between cortisol, a biomarker of stress, and brachial artery flow mediated dilation (FMD) in police officers. A random sample stratified on gender (n=100, 33% women) was generated from officers in a mid-sized urban department. Four salivary cortisol parameters were derived: after awakening, following a standardized high protein meal challenge, during the entire day, and after a dexamethasone suppression test. Continuous scan B-Mode ultrasound was used to measure percent change in brachial artery FMD following occlusion and release. Elevated cortisol secretion after awakening was significantly associated with impaired FMD in women, reflected by an inverse trend. Adjustment for age, smoking, and alcohol consumption did not appreciably alter this trend. A similar result was not evident among male officers. Responses of other cortisol challenges to the HPA axis were not associated with FMD. In conclusion, increased cortisol secretion after awakening was independently associated with impaired FMD in female police officers only, indicating a possible link between HPA axis stress response and subclinical CVD. However, because associations were not found with other cortisol parameters and were not evident in male officers, replication of these findings with a prospective study design may be warranted.