Vulnerability to Stress May Up Risk of Heart DiseaseA large population study from Denmark suggests that people deemed to be “mentally vulnerable” to stress have increased risk for the development of cardiovascular disease.

Study authors explain that psychosocial factors and personality traits have been consistently associated with cardiovascular disease and all-cause mortality, but their role in the prediction of risk was still not clear.

This study investigated whether mental vulnerability (defined as “a tendency to experience psychosomatic symptoms or inadequate interpersonal reactions”), increases the risk of cardiovascular disease.

The study incorporated data from three Danish population cohorts from which almost 11,000 individuals free of any cardiovascular disease were followed-up for a mean period of 15.9 years. During this period all cardiovascular events (fatal and non-fatal) were recorded.

At the beginning of the study, researchers measured mental vulnerability on a validated 12-point scale. The results categorized subjects into three groups: “non-vulnerable, latent or mentally vulnerable”.

“The scale consists of questions on both mental and physical symptoms,” said the study’s first author, Anders Borglykke, Ph.D. Questions generally measured the level of stress or a personality which is more receptive to stress.

Prior studies have found the scale to be associated with early mortality and ischemic heart disease. To assess the predictive ability of the scale, the results were added to a statistical model with classical risk factors for cardiovascular disease (age, sex, smoking, systolic blood pressure and total cholesterol).

During the follow-up period there were 3045 fatal and non-fatal cardiovascular events recorded in the study population of 10,943 subjects.

When the statistical analysis was performed, results showed that mental vulnerability was significantly associated with fatal and non-fatal cardiovascular events independently of the classical risk factors; the risk of events in the mentally vulnerable was 36 percent higher than in the non-vulnerable.

Although the findings show a statistically significant association between mental vulnerability and cardiovascular disease, mental vulnerability should be viewed as part of a larger view of CV disease and not as an independent risk factor.

“Several studies have found risk factors for cardiovascular disease which are clearly independent but within a broader context contribute little if anything to actual risk prediction,” saidBorglykke.

“One of the reasons for this is that the impact of the well established risk factors — age, sex, smoking, blood pressure and total cholesterol — tend to dominate the risk stratification models.

“This means that a risk factor such as our scale of mental vulnerability clearly increases the risk significantly — by 36 percent — but still does not improve risk prediction in the general population.”

“However,” added Borglykke, “these results do not necessarily mean that we should ignore mental vulnerability in our assessment of individual risk. It is still possible that it might improve risk prediction — or even emerge as a new marker to explain or reclassify some cardiovascular cases which cannot be attributed to classical risk factors.

“So mental vulnerability might describe a ‘new dimension’ when compared to the five classical risk factors, but to take this forward we need to identify sub-groups of the population where mental vulnerability does improve risk prediction beyond the classic risk factors.”

Borglykke believes the association between mental vulnerability and cardiovascular disease may be explained by the chronic psychological stress mentally vulnerable people experience. This, he added, might also provide a clue for reducing the risk — by removing the triggers of chronic stress to which such individuals are exposed.

Source: European Society of Cardiology

Stressed businessman photo available from Shutterstock