Body shape may play a big role in determining your chances of suffering a heart attack, increasing the risks for people with more weight around the waist. A new study published in the Journal of the American Heart Association (JAHA) suggests that apple shaped women — those with more fat around their abdomen — are more likely to suffer a heart attack than pear-shaped women — who have more fat around their hips.

UK Biobank, the long-term biobank study investigating the respective contributions of genetic predisposition and environmental exposure to the development of disease, recruited close to 500,000 individuals from the UK for the study. The participants, aged 40 to 69 years, were studied over a period of seven years.

During this time, they recorded 5,710 cases of myocardial infarction or heart attacks within the group, with 28% of them being suffered by women. The research team recognized that while obesity did have profound deleterious effects on the risk of MI in both men and women, the risks were especially higher for women who had a higher waist circumference and waist ‐ to ‐ hip ratio, even if they were not obese.

Waist circumference and waist ‐ to ‐ hip ratio, but not body mass index (BMI) and waist ‐ to ‐ height ratio, were more strongly associated with the risk of MI in women than in men.

"Our findings support the notion that having proportionally more fat around the abdomen (a characteristic of the apple shape) appears to be more hazardous than more visceral fat which is generally stored around the hips (i.e., the pear shape)," said lead author Sanne Peters, PhD, Research Fellow in Epidemiology at the George Institute for Global Health at the University of Oxford, UK.

Typically, apple-shaped individuals are considered to have more fat surrounding their organs which increases their risk of various lifestyle diseases. According to statistics in the AHA's 2018 Statistical Update, 40% of American women aged 20 years and above were considered obese based on 2013-14 national surveys. In comparison, 35% of American men were considered obese.

"Men and women aren't the same, I think we’ve known that for a long time,” said Dr Troy Leo, a cardiologist for Sanger Heart & Vascular Institute at Atrium Health who was not involved in the study. “But the study is showing us that women do have different body types, and those may lead to higher risk of heart disease.

“Women are more prone to heart attacks than we think. I think one of the things about this study is we haven’t studied the differences between men and women enough,” he added.

The study’s authors recommend that more research be conducted to understand the sex differences in obesity in order to pave the way for gender-specific treatments to deal with obesity. They did recognize that while the study was based on a large sample size, the UK Biobank is a largely white population, and further analyses would be needed to determine the generalizability to other populations.