In that psychosocial stress is a risk factor for coronary heart disease (CHD), the mechanism has not been well understood. Avijit Lahirdi, from University College London (United Kingdom), and colleagues studied 514 men and women, average age 62 years, none of whom had heart disease. Subjecting the study participants to stress tests, the team then measured levels of cortisol, a hormone produced in response to stress, and scanned the participants' arteries for signs of furring and narrowing. Those people who were stressed by the tests were twice as likely to have furred arteries as those who remained calm. The researchers conclude that: "In healthy, older participants without history or objective signs of [coronary heart disease], heightened cortisol reactivity is associated with a greater extent of [coronary artery calcification].

Stress can be quantified, measured and reduced by specific medical and psychological interventions.

Mark Hamer, Katie O'Donnell, Avijit Lahiri, Andrew Steptoe. "Salivary cortisol responses to mental stress are associated with coronary artery calcification in healthy men and women." Eur. Heart J., September 10, 2009; doi: doi:10.1093/eurheartj/ehp386.