- The body’s hormonal response to experiencing stress is a natural function that humans and animals have in common.
- Excessive levels of stress hormones, such as norepinephrine, epinephrine, dopamine, and cortisol can adversely affect people’s health.
- A new study suggests that higher levels of stress hormones may have links to an increased risk of high blood pressure and cardiovascular events.
Scientists have studied how the body responds to its environment for years.
Scientists are still exploring the effect of this stress response and the overall impact of stress on long-term health complications.
A new study published in Hypertension, an American Heart Association journal, shows mounting evidence that higher levels of stress hormones may increase a person’s risk of high blood pressure and cardiovascular events.
The body’s stress response is complex and involves multiple hormones, including cortisol. The adrenal glands produce cortisol, which increases energy levels and helps the body react during emergencies.
Epinephrine and norepinephrine both play key roles in the body’s fight or flight response. When exposed to a perceived threat, the fight or flight response prepares the body to face or evade the danger.
Epinephrine and norepinephrine help to:
- constrict blood vessels to maintain blood pressure
- increase heart rate and the force with which the heart pumps blood to the rest of the body
- relax airway muscles
- control the metabolism of glucose
When a person is under stress, the body has higher levels of these hormones. While these stress responses can help short-term, longer-term stress or continued exposure to stress can cause health problems.
As noted by the American Heart Association, chronic stress may lead to high blood pressure, which increases a person’s risk of having a stroke or heart attack. Furthermore, when people experience stress, they may turn to unhealthy coping mechanisms that put them at risk for poor physical health.
This is partly why the American Heart Association has recently focused on stress reduction techniques as a vital component of overall health. In a recent Facebook post, they shared tips for stress reduction from Psychiatry Professor Dr. Helen Lavretsky.
Dr. Lavretsky emphasized how people can utilize several techniques for stress reduction, including looking for joyous moments throughout the day, finding things to be grateful for, and using slowed breathing techniques.
Scientists are still exploring the relationship between stress hormones and risks of cardiovascular problems, and the study in question offers further information.
The research — carried out by scientists from the University of California in Los Angeles — is a prospective cohort study that examines the association between higher levels of stress hormones and increased risk of high blood pressure and cardiovascular events.
The study included 412 adults ages 48–87 years. Participants had no previous history of high blood pressure, which was one of the key differences between the current and previous studies. The study also involved a diverse mix of participants, including white, Black, and Hispanic individuals.
Researchers took into account the participants’ sex, education level, income, and health insurance status. They also examined their lifestyle factors, including whether they drank alcohol, smoked, and did any physical activity.
Finally, researchers looked at the health status of the participants, including whether they had diabetes, their use of any medications, body mass index, and kidney function.
This study was part of a larger study called the Multi-Ethnic Study of Atherosclerosis (MESA). At the start of the study, the researchers asked a subset of participants from the larger study with no diagnosed cardiovascular disease to participate in a 12-hour overnight urine collection. The researchers analyzed the urine for levels of epinephrine, norepinephrine, dopamine, and cortisol.
The researchers included participants who had no hypertension at baseline and had complete data and specific covariates in further data analysis.
Researchers followed up with participants for an average of 6.5 years to evaluate hypertension. During the years of follow-up, 48.8% of participants had developed high blood pressure. Over the average follow-up of 11.2 years, 5.8% of participants experienced cardiovascular events. Cardiovascular events included heart attacks, coronary heart disease death, stroke, and the development of peripheral vascular disease.
Using multivariable Cox proportional hazard models, researchers calculated the risk of high blood pressure and cardiovascular events associated with urinary stress hormones.
Results revealed that higher levels of stress hormones in the urine have associations with a greater risk of high blood pressure. The researchers found this association was stronger among younger individuals than among older individuals.
They further found that a double than normal level of urinary cortisol has associations with a higher incidence of cardiovascular events. They did not find an association between higher levels of catecholamines and cardiovascular events.
The study accounted for several factors and included a diverse sample. However, researchers do acknowledge the study’s limitations. Due to the nature of the 12-hour overnight urine collection, there was the possibility for errors in specimen collection.
The authors also acknowledge the possibility of sample bias and unaccounted influencing factors. For example, their analysis method did not account for the stratified analysis of cardiovascular events. The researchers also did not differentiate the causes of the developed high blood pressure.
Considering these limitations and the small sample size of the study, researchers encourage the following when it comes to continued data collection in this area:
- continued long-term studies that look at urinary stress hormones and include larger sample sizes
- studies that do multiple measurements of urinary stress hormone levels
- studies that account for the causes of high blood pressure
- more inclusion of factors that can influence a study’s results
Overall, the results indicate the importance of taking psychological stress into account to create a holistic view of health and help prevent long-term complications. Professor of Medicine and cardiology specialist Dr. Glenn N. Levine told MNT:
“It has been clearly established that psychological health can positively impact cardiovascular health. Stress is one of the important factors when one considers negative psychological health. This study demonstrated that elevated stress hormones were associated with an increased risk of developing high blood pressure and an increased risk of overall cardiovascular events. It further adds to our appreciation of the fact that we, as healthcare professionals, must pay attention to not only the heart and the patient but also to the mind and the person as a whole..”
Dr. Glenn, a Professor of Medicine at Baylor College of Medicine in Houston, Texas, and co-authored the study. MNT also reached out to Prof. Bernard Cheung, Ph.D., FRCP, Sun Chieh Yeh Heart Foundation Professor in Cardiovascular Therapeutics at the University of Hong Kong.
Prof. Cheung, who was not involved in the research, felt that the study findings were “interesting.” However, he said, people should interpret the results with caution.
“Firstly, association is not the same as causation. One should not jump to the conclusion that hypertension can be prevented by stress management,” Prof. Cheung said.
“Secondly, there is a phenomenon known as white coat hypertension. People with white coat hypertension are more nervous, and their blood pressure goes up when it is being measured. Thirdly, the study did not analyze men and women separately. Finally, it would have been better if [the researchers] had measured stress using a questionnaire to supplement the data from urinary hormones,” added the expert.