High levels of stress caused by adverse life events and financial problems heighten the risk of cardiovascular disease, according to a study published in the journal JAMA Network Open.

The study included more than 118,000 individuals from 21 countries – five of which were low-income, 12 middle-income, and four high-income countries – with a mean age of 50 years.

Participants who were severely stressed had a 22% increased risk of experiencing a cardiovascular event

Participants were asked questions about perceived stress and then asked to rate their stress on a scale from zero (no stress) to three (severe stress).

“Stress” was defined as feeling nervous, irritable or anxious because of factors at work or at home, being in financial difficulties, or having experienced difficult events and challenging times in their lives. Adverse events included divorce, unemployment, bereavement or serious illness in a family member.

After analysing the findings, 7.3% were found to have been subject to severe stress, 18.4% to moderate stress, 29.4% to low stress, and 44% experienced no stress. Those who were severely stressed were more likely to be younger, characterised by risk factors such as smoking and obesity, and from high-income countries.

The participants were followed up over a 10-year period, during which time 5,934 cardiovascular events in the form of myocardial infarction, stroke, or heart failure were recorded.

After adjusting for risk factors, it was found that participants who were severely stressed had a 22% increased risk of experiencing a cardiovascular event, a 24% increased risk of a heart attack and 30% increased risk of stroke.

Approaches to reducing stress could reduce the rate of cardiovascular disease

This study sought to classify stress levels before the cardiovascular event occurred, as previous studies have largely considered stress levels in people who had already undergone a heart attack or stroke, which may have affected the response.

Co-author Annika Rosengren, Professor of Medicine, University of Gothenburg, said that study’s findings indicate that approaches to reducing stress could reduce the rate of cardiovascular disease.

She said: “It's not known exactly what causes the elevated risk of cardiovascular disease among the severely stressed people, but many different processes in the body, such as atherosclerosis and blood clotting, may be affected by stress.”

"If we want to reduce the risk of cardiovascular disease globally, we need to consider stress as another modifiable risk factor,” she concludes.