Cortisol levels in hair may be the first biomarker to measure chronic (long-term) stress, which is linked to a higher risk of having a heart attack (acute myocardial infarction), according to a new study published in the medical journal Stress. Employment, marital, bereavement, and financial problems are examples of stressors that have been associated with a higher heart attack risk, say the authors. But no previous study has come up with a biological market to measure chronic stress.

Investigators from Canada and Israel developed a way of measuring hair cortisol levels, providing an accurate measurement of stress levels in the months preceding an acute event, such as a heart attack.

Cortisol is a stress hormone - we secrete it when they are under stress. Traditional measurements of stress do not show stress levels over long periods. Typically, cortisol levels have been measured using serum, saliva or urine tests. However, cortisol is captured in the hair shaft, giving us an idea of its levels in the human body over longer periods.

Gideon Koren, who holds the Ivey Chair in Molecular Toxicology at Western's Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada, said:

Intuitively we know stress is not good for you, but it's not easy to measure. We know that on average, hair grows one centimetre (cm) a month, and so if we take a hair sample six cm long, we can determine stress levels for six months by measuring the cortisol level in the hair.

The researchers collected three centimeter-long hair samples from 56 adult males who had been hospitalized at the Meir Medical Centre, Kfar-Saba, Israel, following a heart attack.

They also collected samples from a control group consisting of 56 men who had also been hospitalized, but not for heart attacks.

They discovered that hair cortisol levels during the last three months before hospitalization were clearly higher in the heart attack patients than in the control group.

The heart attack and control groups had similar heart attack factors, such as hypertension, smoking and family histories of coronary artery disease. The investigators did find more cholesterol problems among the heart attack patients.

After taking into account known risk factors, the scientists report that cortisol content emerged as the strongest predictor of heart attack.

Koren said:

Stress is a serious part of modern life affecting many areas of health and life. This study has implications for research and for practice, as stress can be managed with lifestyle changes and psychotherapy. Cortisol and stress Cortisol is the primary stress hormone. Cortisol is the major natural glucocorticoid (GC) in humans.

We use the word stress when we feel that everything seems to have become too much - we are overloaded and wonder whether we really can cope with the pressures placed upon us. Anything that poses a challenge or a threat to our well-being is a stress. Some stresses get you going and they are good for you - without any stress at all many say our lives would be boring and would probably feel pointless. However, when the stresses undermine both our mental and physical health they are bad.

The way we respond to a challenge may be a type of stress. Part of our response to a challenge is physiological and affects our physical state. When faced with a challenge or a threat, the body activates resources to protect us - to either get away as fast as we can, or fight. If you are upstairs at home and an earthquake starts, the faster you can get yourself and your family out the more likely you are all to survive. If you need to save somebody's life during that earthquake, by lifting a heavy weight that has fallen on them during the earthquake, you will need components in your body to be activated to give you that extra strength - that extra push.

Our fight-or-flight response is our body's sympathetic nervous system reacting to a stressful event. Our body produces larger quantities of the chemicals cortisol, adrenaline and noradrenaline, which trigger a higher heart rate, heightened muscle preparedness, sweating, and alertness - all these factors help us protect ourselves in a dangerous or challenging situation.

The most common causes of stress are: Bereavement Family problems Financial matters Illness Job issues Lack of time Moving home Relationships (including divorce) The following are also causes of stress Abortion Becoming a parent Conflicts in the workplace Driving in bad traffic Fear of crime Losing your job Miscarriage Noisy neighbors Overcrowding Pollution Pregnancy Retirement Too much noise Uncertainty (awaiting laboratory test results, academic exam results, job interview results, etc) "Hair cortisol and the risk for acute myocardial infarction in adult men"
David Pereg, Rachel Gow, Morris Mosseri, Michael Lishner, Michael Rieder, Stan Van Uum, Gideon Koren
Stress: The International Journal on the Biology of Stress
Posted online on September 2, 2010. (doi:10.3109/10253890.2010.511352)