Obesity Measure Should Be Redefined to Accurately Assess Heart Attack Risk
ratio, not body mass index (BMI), is the best obesity measure for
assessing a person’s risk of heart attack, concludes a global
study published in a recent issue of The Lancet.
If obesity is
redefined using waist-to-hip ratio instead of BMI the proportion of
people at risk of heart attack increases by threefold, calculate the
research has shown that obesity increases the risk of heart disease.
However, these studies have mainly been done in populations of European
and North American origin. The evidence for other populations is
therefore sparse. In the latest study, Dr. Salim Yusuf, director of the
Population Health Research Institute at McMaster University and
Hamilton Health Sciences, and colleagues aimed to assess whether other
markers for obesity, especially waist-to-hip ratio, would be a stronger
predictor of heart attack than the conventional measure of BMI in
different ethnic populations.
investigators looked at BMI, waist-to-hip ratio, waist measure, and hip
measure in more than 27,000 people from 52 countries. Half the
participants had previously had a heart attack and half were age and
sex-matched controls (individuals who had not had a heart attack and
were the same age and sex as cases).
found that BMI was only slightly higher in heart attack patients than
in controls, with no difference in the Middle East and South Asia. By
contrast, heart attack patients had a strikingly higher waist-to-hip
ratio than controls, irrespective of other cardiovascular risk factors.
The researchers found that this observation was consistent in men and
women, across all ages, and in all regions of the world.
authors’ state that compared with BMI, waist-to-hip ratio is
three times stronger than BMI in predicting the risk of a heart attack.
Larger waist size (which reflects the amount of abdominalfat) was
harmful, whereas larger hip size (which may indicate the amount of
lower body muscle) was protective.
waist-to-hip ratio is calculated by dividing the waist measure by the
hip measure. The cut off point for cardiovascular risk factors is less
than 0.85 for women and 0.90 for men. Dr. Yusuf concludes: "Our
findings suggest that substantial reassessment is needed of the
importance of obesity for cardiovascular disease in most regions of the
Dr. Yusuf is
a professor of medicine of the Michael G. DeGroote School of Medicine
at McMaster University, a cardiologist at Hamilton Health Sciences. He
also holds the Heart and Stroke Foundation of Ontario Chair in
Cardiology at McMaster University. The study was funded by the Canadian
Institutes of Health Research, the Heart and Stroke Foundation of
Ontario and 37 other funding sources, including unrestricted support
from several pharmaceutical companies.
accompanying published comment Charlotte Krageland of the University of
Oslo, Norway states: "The main message from the new report is that
current practice with body mass index as the measure of obesity is
obsolete. For the assessment of risk associated with obesity, the
waist-to-hip ratio, and not the body mass index, is the preferred
Kelton, dean of the Michael G. DeGroote School of Medicine and dean and
vice-president, Faculty of Health Sciences, McMaster University, said:
"The results of this study will change, on an international scope, how
we evaluate patients’ risks for heart disease. Being able to
easily identify the risk will have a beneficial effect on awareness and
Bernstein, president of the Canadian Institutes of Health Research,
said: "We’ve long been aware of the link of obesity and
cardiovascular disease. Thanks to the research conducted by Dr. Yusuf,
we now have a better understanding of the risk related to obesity which
can lead to more effective health interventions.
Martin, president and CEO of Hamilton Health Sciences, said: "Part of
our mission as a teaching hospital is to advance health care through
education and research. Dr. Yusuf's commitment to finding answers to
important heart health questions that affect people around the world
exemplifies the leadership we embrace at Hamilton Health Sciences."
For more information, visit www.phri.ca