A group of researchers followed up a population of siblings and tried to estimate the connection between stress-related conditions and heart disease. Their study titled “Stress related disorders and risk of cardiovascular disease: population based, sibling controlled cohort study,” was published in the latest issue of the journal BMJ.
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The team at the University of Iceland and the Karolinska Institute, Sweden, looked at a large population from Sweden including 136,637 patients in the Swedish National Patient Register. These participants were suffering from stress related disorders including acute reaction to stress, problems with adjustment, stress reactions and Post Traumatic Stress Disorder (PTSD). The participants were followed up from 1987 to 2013. The sufferers were matched with 171,314 of their siblings who did not have the stress related disorders and also with 1,366,370 matched participants or controls from the general population who did not have stress related conditions. The team analysed the incidence of heart disease in each of the groups. Heart disease according to them included, “ischaemic heart disease, cerebrovascular disease, emboli/thrombosis, hypertensive diseases, heart failure, arrhythmia/conduction disorder, and fatal cardiovascular disease.”
Over 27 years of the follow up of the participants, the team found that the incidence of heart disease was 10.5, 8.4, and 6.9 for every 1,000 person years for the sufferers of stress related conditions, non-stressed siblings and unaffected matched controls respectively. The researchers found that the risk of stress causing heart failure was highest when siblings were compared with or without stress. This risk was greatest in the first year after being diagnosed with a stress related condition. Stress related disorders were also connected with early onset heart disease with incidences seen before the age of 50 years.
Lead researcher Dr Huan Song, a post doctoral student said, “Most people are, at some point during their life, exposed to psychological trauma or stressful life events such as the death of a loved one. Accumulating evidence suggests that such adversities might lead to an increased risk of several major diseases and mortality.”
The authors of the study speculate that response to stress may affect the heart and the cardiovascular system by raising the blood pressure and this can lead to cardiovascular disease. They conclude that there seems to be “a clear association between clinically confirmed stress related disorders and a higher subsequent risk of cardiovascular disease, particularly during the months after diagnosis of a stress related disorder.” They add that the problem seems to be similar among both men and women. Their suggestion in the conclusion is, “enhanced clinical awareness and, if verified, monitoring or early intervention among patients with recently diagnosed stress related disorders.”
Professor Simon Bacon, from Concordia University, Montreal, in an accompanying editorial wrote that people with heart disease are also at a greater risk of stress and related disorders. That causation cannot be ruled out he wrote adding, “Heart failure is often a slowly evolving chronic disease, so reverse causation cannot be ruled out entirely.”