Cortisol Levels in Hair Reveal Link Between Stress and Heart Attack

Researchers at Meir Medical Center (Kfar Saba; Israel) and the University of Western Ontario (London, Canada) conducted a prospective case-control study that included 56 patients admitted to the hospital with AMI, and 56 control patients who were admitted to internal medicine wards for other indications. The researchers used an enzyme immunoassay technique to measure cortisol in the most proximal 3 cm of hair, considered to represent the most recent 3 months of exposure. The aim of the study was to evaluate the hypothesis that chronic stress, as assessed by hair cortisol content, is associated with the development of AMI.

The researchers found that median hair cortisol contents were 295.3 ng/g in AMI patients, compared to 224.9 ng/g in the control patients. The prevalence of diabetes, hypertension, smoking, and family history of coronary artery disease (CAD) did not differ significantly between the two groups, although the AMI group had more cholesterol problems. After accounting for the known risk factors for AMI using multiple logistic regression, log-transformed hair cortisol content remained the strongest predictor. The study was published ahead of print on September 2, 2010, in Stress.

"Intuitively we know stress is not good for you, but it's not easy to measure,” said lead author molecular toxicologist and cardiologist Gideon Koren, M.D., Ph.D. "We know that on average, hair grows one centimeter a month, and so if we take a hair sample six centimeters long, we can determine stress levels for six months by measuring the cortisol level in the hair.”

Cortisol, also known as hydrocortisone, is a steroid hormone (glucocorticoid) produced by the adrenal gland. It is released in response to stress, and to a low level of blood glucocorticoids. Its primary functions are to increase blood sugar through gluconeogenesis, suppress the immune system, and aid in fat, protein, and carbohydrate metabolism; it also decreases bone formation. Although cortisol secretion in response to stress is a natural function, prolonged cortisol secretion as a result of chronic stress could result in significant physiological changes.

Related Links:
Meir Medical Center
University of Western Ontario