Salivary cortisol is related to atherosclerosis of carotid arteries

Background: Dysregulation of the hypothalamic-pituitary-adrenal axis has been suggested as an independent risk factor for ischemic heart disease. The aim of our study was to evaluate whether two markers of the hypothalamic-pituitary-adrenal axis activity, the level of salivary cortisol and the diurnal salivary cortisol pattern, are associated with atherosclerosis of the carotid arteries in an elderly population. Methods and Results: A total of 1866 participants of the Rotterdam Study, a population-based cohort study in the elderly, provided four salivary cortisol samples throughout 1 d, and underwent ultrasonography to examine the presence of plaques in the common, internal, and bifurcation sites of both carotid arteries. Two summary measures of the separate cortisol values were computed: area under the curve (AUC), which is a measure of total cortisol exposure while awake; and the slope, which is a measure of diurnal cortisol decline. Results: Total cortisol exposure while awake (AUC) was associated with higher plaque scores (beta = 0.08 per SD of AUC, 95% confidence interval 0.00-0.16; P = 0.04) in a fully adjusted linear regression model. Persons with an AUC in the highest tertile had a higher number of plaques of carotid arteries compared with those in the lowest tertile (3.08 vs. 2.80, 95% confidence interval of difference 0.09-0.48; P = 0.005). There was no relation between diurnal cortisol decline and plaque score. Conclusion: Our results support the hypothesis that increased total cortisol exposure is independently associated with atherosclerosis of the carotid arteries.