"Women at greater risk of heart attack from unhealthy lifestyle than men," reports The Daily Telegraph.
Overall, men are more likely to have heart attack than women, but some risk factors such as smoking can bridge the gap between women and men.
The researchers looked at data on nearly 472,000 people in the UK aged 40-69. They found that overall, men had a much higher risk of heart attack than women over 7 years of follow-up. However, the effects of smoking, diabetes and high blood pressure have increased the relative risk of a heart attack for women compared to that which increased the risk in men.
For example, female smokers were about 3.4 times the risk of having a heart attack like women who had never smoked, while male smokers were 2.2 times the risk of men who had never smoked.
The researchers warn that women could eventually "recover" with the risk of heart attack of men, as the population ages and conditions such as diabetes and hypertension become more common. They say doctors need to be more alert to the risk of heart attacks in women and ensure women with high blood pressure and diabetes access the best treatments for their condition and advice on preventing heart attacks.
Find out more about how to keep your heart healthy.
Where does the story come from?
The researchers who carried out the study came from the University of Oxford. The study was funded by the British Medical Research Council and the National Health and Medical Research Council. It has been published in the British Medical Journal peer-reviewed on an open-access basis, so it is free to read online.
The coverage in the British media has been thwarted because some sources have not made it clear that an increase in the relative risk is not the same as an increase in the absolute risk.
One way to understand the difference is to imagine that you bought a lottery ticket and the next hour you bought a second ticket. Your "risk" related to winning the lottery would increase by 100% but your absolute risk would still be extremely small.
The title of Mail Online: "Overweight women are increasing their chances of suffering a heart attack more than overweight men", it is wrong because the researchers did not find any difference in the relative risk of overweight among men and women.
While the Telegraph's explanation that "per person, smoking, hypertension and diabetes produced a greater likelihood of heart attack in women than men" is not clear. The overall absolute risk of men having a heart attack remains higher. But smoking, hypertension and diabetes increase a woman's relative risk more than the relative risk of a man increases.
BBC News explained the study well in a balanced article.
what kind of research was this?
This was a cohort study, using data from a large ongoing study of UK adults. The researchers wanted to untangle the effects of various heart attack risk factors on men and women, at different ages.
A cohort study is a good way to examine the effects of risk factors on large groups of people. However, they can not prove that risk factors directly cause the outcome (heart attack in this case) because other factors may be involved.
What did the research involve?
The researchers used data from the UK Biobank, a study that recruited half a million UK adults between the ages of 40 and 69 between 2006 and 2010. Participants performed various tests and tests including blood pressure, weight and height and have filled out questionnaires about their lifestyle and their medical history.
For this study, the researchers focused on:
- history of cardiovascular diseases
- diabetes status (eg a confirmed diagnosis of type 1 or type 2 diabetes)
- atrial fibrillation (irregular heartbeat)
- measurements of arterial pressure
- state / history of smoking
- body mass index
- if they were taking medication to treat diabetes or hypertension
The socio-economic status was assessed by postal code. People were monitored through health records to see if they had a heart attack during the next 7 years.
Using these data, the researchers examined the links between blood pressure, smoking, diabetes, body mass index, atrial fibrillation and socioeconomic status and heart attack, performing analyzes separately for men and women. They also examined the risks in the 5-year age groups to see how age affected the results.
What were the basic results?
After an average of 7 years of follow-up, 5,081 people had a first heart attack. More men than women were affected, with 71% of heart attacks in men and 29% in women. This difference has slightly decreased among those aged 65 and over.
High blood pressure
The researchers found that men and women with high blood pressure were more likely to have a heart attack. More severe hypertension increases the risks for women more than for men.
Stage 2 hypertension (160/100 mmHg or more) increased the risk for women by 252% (hazard ratio (HR) 2.52, 95% confidence interval (CI) from 2.04 to 3.13). increased risk for men by 171% (HR 1.71, 95% CI from 1.46 to 2.01)
Smokers and former smokers had an increased risk of heart attack, but this increased risk was more pronounced in women.
Women smokers increased the risk by 346% (HR 3.46, 95% CI 3.02 to 3.98) compared to women who had never smoked, while men who smoked had a higher risk of 223% (HR 2.23, 95% CI 2.03-2.44) compared to men who had never smoked
Women with type 1 diabetes had an 818% increase in the risk of heart attack compared to women without diabetes (HR 8.18, 95% CI from 5.20 to 12.86). Men with type 1 diabetes had a 281% increase in heart attack risk compared to men without diabetes (HR 2.81, 95% CI 1.82-4.33).
Women with type 2 diabetes had a 96% increase in the risk of heart attack (HR 1.96, 95% CI 1.6 to 2.41) compared to women without diabetes and men with type 2 diabetes had a 33% increase in the risk of heart attack (HR 1.33, 95% CI 1.18-1.51) compared to men without diabetes.
Body mass index
While overweight or obesity were related to an increased risk of heart attack, there was no difference in the increased risk between men and women.
Atrial fibrillation was not related to an increased risk of heart attack for women, although it was linked to a slightly higher risk for men.
The effects of risk factors such as blood pressure have decreased over time for men and women, while the chances of a heart attack have increased with an increase in age. However, the difference in the impact of risk factors on men and women persisted.
How did the researchers interpret the results?
The researchers said: "Our results suggest that doctors should be vigilant when their patients are elderly, they smoke, have diabetes or have high blood pressure." They say their findings also highlight "the importance of equitable access to treatments based on guidelines for diabetes and hypertension, and to weight loss and smoking cessation programs for women and men aged medium and advanced ".
The study shows the great impact that factors such as smoking, hypertension and diabetes can have on the odds of having a heart attack.
While the risk increases for women is greater than for men, the risk increases for men are still considerable. The study emphasizes the importance of not smoking and controlling blood pressure and diabetes for both women and men.
There are some limitations to the study:
- data on smoking, diabetes, atrial fibrillation and drugs taken for these conditions have been self-reported, which means it may not be accurate
- we do not know about some important risk factors for heart attack, such as people's cholesterol levels
- some participants did not answer all the questions, especially about smoking, where over 5% of people did not say how many cigarettes they smoked every day
While the overall risk of a heart attack has remained much higher for men than women in the study, it serves to emphasize that some groups of women have a much higher risk than other women. It is important to be aware of the risk of a heart attack, especially if you are a woman in one of the highest risk groups.
Symptoms of a heart attack are sometimes less clear in women than men. Symptoms may include chest pain, arm pain, jaw, neck and back, dizziness, sweating, shortness of breath, feeling of nausea, feeling of anxiety or panic, coughing or wheezing. The pain may not be severe, and sometimes women or people with diabetes do not feel any pain, or a minor pain like indigestion. If you suspect someone is having a heart attack, it's a medical emergency. Call 999 immediately and ask for an "ambulance".
Find out more about the symptoms of heart attack.