The 2-minute tape measure test that can predict if you’ll die from a heart attack, study suggests

The fat around your middle is a better indication of your heart attack risk than your body weight, a study has suggested.

Researchers said this measure accurately detected those at a potentially 50 per cent higher risk of nine major heart problems, including stroke and heart failure.

Body mass index, or BMI alone, was found to be a far less reliable indicator of the life-threatening health problems. 

The research suggests that up to a fifth of those with a healthy BMI score could in fact be carrying dangerous amounts of body fat.

BMI is calculated by dividing an adult’s weight in kilograms by height in metres squared, and is widely used to determine whether a person is at a ‘healthy weight’.

Around a third of Britons are thought to be obese – a BMI of more than 30 – and at significant risk of a host of dangerous complications from type 2 diabetes to cancer.

However, experts have long argued that BMI does not capture the full picture of a person’s health as it fails to account for body fat, particularly around the stomach – which is a known driver of organ damage.

In the new study, published in the Journal of the American College of Cardiology (JACC), the team measured 260,000 participants’ waist circumference and waist-to-hip ratio, alongside BMI.

Waist circumference measures the distance around the abdomen, while waist-to-hip ratio compares this figure with that of the hip circumference, which provides greater insight into the body fat in the area.

The US researchers examined participants’ health records over a period of 20 years, and found that 18 per cent of people who were classed as a ‘healthy’ weight by BMI had a worryingly high waist-to-hip ratio, while five per cent had a risky waist circumference. 

Despite being classed as a healthy weight, participants had high central adiposity – the term for excess fat in the lower stomach.

This type of fat, known as visceral fat, wraps around the organs in the stomach such as the liver and pancreas.

While everyone has some kind of visceral fat, too much can damage these areas and trigger life-threatening complications.

Experts recommend the hip-to-waist ratio measurement as a simple and reliable way for people to calculate this risk. 

In the study, those with an unusually high waist or waist-to-hip ratio were at a 15 to 50 per cent greater risk of most of the nine health outcomes studied.

These included heart attack or stroke, heart failure, atrial fibrillation, coronary heart disease and cardiovascular disease, as well as deaths from any cause. 

Michael J. Blaha, senior author of the study, said: ‘We saw individuals with clinically determined normal weight who had elevated central adiposity and high [waist-to-hip ratio], associating them with higher risk across most outcomes.’

Only around four in ten people classed as overweight by BMI had a high waist-to-hip ratio. 

This was true for around half of the participants classed as obese, according to BMI. 

Those with obesity and a smaller waist were also found to be at no higher risk of heart problems than normal-weight people with a similarly-sized waist. 

Researchers said the findings highlight the importance of analysing where body fat is carried, rather than relying on BMI alone.

They warned the measurement may lead to some being told they’re at greater risk of heart problems when they’re not, and vice versa.

Zeina Dardari, lead author of the study from Johns Hopkins Ciccarone Centre for the Prevention of Cardiovascular Disease said: ‘Relying solely on BMI may result in misclassification of cardiovascular risk across a wide range of cardiovascular outcomes.

‘We encourage clinicians to consider central adiposity distribution across the entire BMI spectrum when evaluating cardiovascular risk.’

Harlan M Krumholz, editor-in-chief of JACC and Yale School of Medicine scientist, added: ‘It is time to abandon a sole focus on body mass index.

‘This enormously important study, based on data from hundreds of thousands of participants, authoritatively shows that waist circumference and waist-to-hip ratio provide critical information about cardiovascular risk, even among people with a BMI considered normal. 

‘Where fat is distributed matters, and these simple measures should be part of routine cardiovascular risk assessment.’

Researchers acknowledged the study’s limitations, including that it did not have measures of physical activity, diet or genetic obesity risk, all of which have been linked to cardiovascular disease.

Waist measurements were also recorded only once, so the team could not assess how any potential changes in fat over time affected heart health risk.