“Having a hot temper may increase your risk of having a heart attack or stroke, according to researchers,” BBC News reports.
Researchers conducted a systematic review, collating the findings of previous studies. Their results suggest that outbursts of anger increase the risk of a serious cardiovascular event by almost fivefold (4.74, to be exact).
However, there are a few flaws to the research. The most pertinent is that some of the studies included in the review collected information after the cardiovascular event occurred. This type of information gathering is prone to what is known as recall bias.
For example, if a person has a heart attack in the afternoon, they may be more likely to remember the driver that “cut them up” at a roundabout that morning than someone who didn’t experience a cardiovascular event.
There could also be other factors that link anger and cardiovascular events and are responsible for the association seen.
Finally, no studies used in the analysis looked at the general population and whether anger levels increased their likelihood of having a cardiovascular event. The researchers said the results “should not be assumed to indicate the true causal effect of anger episodes on cardiovascular events”.
That said, frequent outbursts of anger are not good for either your mental or physical health. Read more advice about ways you can control your anger.
The study was carried out by researchers from Harvard Medical School, Harvard School of Public Health and New York-Presbyterian Hospital/Weill Cornell Medical Centre, New York. It was funded by the US National Institutes of Health.
The results of the research were well reported by the UK media. They put the small risk of a cardiovascular event into its proper context, while also pointing out that unresolved anger can impact on a person’s health.
This was a systematic review that aimed to find out whether episodes of anger are linked to a short-term risk of experiencing a cardiovascular event, such as a heart attack, stroke or disturbances in heart rhythm.
Systematic reviews are the best way of determining what is known about a topic.
However, it’s worth considering that this systematic review contained case-crossover studies. In these, information on whether the participants were angry or calm was obtained during two different periods of time: immediately before the cardiovascular event and at an earlier time.
The level and frequency of anger just prior to a cardiovascular event was then compared to the level of anger in the same people at an earlier time.
Although case-crossover studies can show a link between two things, there could be other factors at play. In this instance, there could be numerous reasons for the link between anger and cardiovascular events. As mentioned previously, case-crossover studies are also prone to recall bias.
The researchers searched databases of literature to identify all studies that had evaluated whether outbursts of anger are linked to a short-term risk of heart attack, stroke or disturbances in heart rhythm. For studies to be included, they had to evaluate triggers occurring within one month of the cardiovascular event.
The results of these studies were then combined to see if anger was associated with the short-term risk of one of these events. The researchers calculated incidence rate ratios, which compared the number of cardiovascular events in the two hours following outbursts of anger with the number of cardiovascular events that weren’t preceded by anger.
The researchers identified and included nine case-crossover studies:
The studies were substantially different – they were performed in different countries and collected information about anger episodes differently.
The researchers found there was a 4.74 times higher risk of heart attack/acute coronary syndrome in the two hours following outbursts of anger compared to normal (95% Confidence Interval [CI] 2.50 to 8.99).
The risk of having a stroke was not significantly higher in the two hours following anger compared to normal (95% CI 0.82 to 16.08).
The one study that assessed the risk of ruptured intracranial aneurysms found a statistically significant increased risk in the hour following an outburst of anger (95% CI 1.59 to 24.90).
The two studies that analysed whether outbursts of anger are associated with ventricular arrhythmia were too different to be combined, but both studies found that anger episodes significantly increase a person’s risk.
Researchers point out that although the relative risks of cardiovascular events following an anger outburst are large, the impact on an individual’s absolute risk of a cardiovascular event may be small.
This is because the initial baseline risk of experiencing a cardiovascular event is small.
That said, when we consider the increased risk at population levels, it seems that frequent outbursts of anger do take a toll on the public's health.
They calculate, based on the combined estimate of a 4.74 times higher rate of heart attack/acute coronary syndrome in the two hours following outbursts of anger, that:
The researchers concluded that, “there is a higher risk of cardiovascular events shortly after outbursts of anger”.
This systematic review found there is an increased risk of cardiovascular events, including heart attack and disturbances in heart rhythm, shortly after outbursts of anger.
This is based on results from nine case-crossover studies. In these, information on feelings of anger in the period before the cardiovascular event, as well as an earlier period, were collected retrospectively. The risk of having a cardiovascular event after an episode of anger was then calculated.
The researchers point out several limitations to their review, including the fact that:
Although case-crossover studies can demonstrate a link, there could be other factors that link anger and cardiovascular events and are responsible for the association seen. The researchers concluded that “the results should not be assumed to indicate the true causal effect of anger episodes on cardiovascular events”.
Anger is a normal, healthy emotion. However, if you find yourself getting intensely angry on a regular basis, you may have an anger management problem. Read more about possible treatment options that could help you control your anger.