Diurnal cortisol decline is related to coronary calcification: CARDIA study

Chronic stress may be a risk factor for coronary heart disease and is associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. We tested the hypotheses that two markers of HPA axis dysregulation, elevated average level (area under the curve, adjusted for time awake) and diurnal decline of salivary cortisol, were associated with presence of coronary calcification (CaC).

Seven hundred eighteen black and white middle-aged adults enrolled in an ancillary study of Coronary Artery Risk Development in Young Adults provided six salivary cortisol samples throughout one full day and had measurements of CaC.

The prevalence of any calcification was low, 8.1% in the participants of the ancillary study, with white men having the highest proportion. Average cortisol did not differentiate groups, means = 2.15 and 2.08. Those with any CaC declined approximately 6% per hour in cortisol over the course of the day, whereas those with no CaC declined more than 8% per hour (p < .003). Those persons with slope scores in the flattest quartile had a greater likelihood of any CaC than did those in the remaining quartiles adjusted for sex-race group, age, smoking, treatment for diabetes, systolic blood pressure, logged triglycerides, average cortisol, and educational attainment (odds ratio = 2.58; 95% confidence interval = 1.26-5.30).

Our results are consistent with the hypothesis that HPA axis dysregulation may affect risk for atherosclerosis.