Though obesity is a factor for heart attack for everyone, women are at a greater risk with a larger waist circumference and waist-to-hip ratio, according to new research from the Journal of the American Heart Association.

Researchers sought to assess the gender-specific relationship between the risk incident of MI among women and men without a prior history of cardiovascular disease (CVD) and measures of general and central adiposity.

“This study suggests that the sex dimorphism in the quantity and distribution of adipose tissue not only results in differences in body shape between women and men but may also have differential implications for the risk of myocardial infarction in later life,” wrote lead author Sanne A. E. Peters, PhD, with the George Institute for Global Health, University of Oxford in England, and colleagues.

Using a study cohort of more than 500,000 individuals aged 40 to 69, from the UK Biobank, researchers followed up with the participants after seven years. Approximately 5,700 cases (28 percent women) of MI were recorded in the cohort with no history of CVD at the beginning of the study.

The mean waist circumference, waist-to-hip ratio and waist-to-height ratio, were 85 cm, 0.82 and 0.52 in women and 97 cm, 0.93, and 0.55 in men, respectively. Correlation coefficients among BMI, waist circumference and waist-to-height ratio were 0.88 and above for both groups. Correlations with waist-to-hip ratio were 0.46 in women and 0.59 in men for BMI, 0.75 in women and 0.80 in men for waist circumference, and 0.75 in women and 0.80 in men for waist-to-height ratio.

The researchers noted waist-to-hip ratio and waist circumference were 15 percent and 7 percent, respectively, which were more strongly tied to heart attack risk in women than men.

In both men and women, the waist-to-hip ratio was a better predictor of heart attacks than BMI—18 percent in women and 6 percent in men. Women with “apple-shape” figures—women with more fat around the abdomen—had a higher heart attack risk than women with a “pear-shape” figure, with fat generally more around the hips.

“Although several measures of general and central adiposity each have profound deleterious effects on the risk of MI in both sexes, a higher waist-to-hip ratio and waist circumference conferred a greater excess risk of MI in women than men,” the authors concluded. “Waist-to-hip ratio was more strongly associated with the risk of MI than BMI in both sexes, especially in women.”