Research from the University of Texas found
large waist measurements, relative to hip size, were linked
to early signs of heart disease.
This confirms other research that waist size,
rather than overall body weight, is a key indicator of heart
disease.
The study of 2,744 people suggests that a waist
size of 32ins (81cm) for a woman and 37ins (94cm) for a man
represents a "significant" raised risk.
The report was published in the Journal of
the American College of Cardiology.
The authors looked at men and women who underwent
medical tests and imaging scans to identify the early signs
of atherosclerosis - the narrowing and hardening of the arteries
linked to the development of cardiovascular disease.
Body shape important
They then examined the relationship between
the participants' body shapes and the presence of atherosclerosis.
They found adding a few inches to the waist
increased the risk of damage in the arteries, even if body weight
remained within the normal range.
People with the largest waist-to-hip ratios
(WHRs) were almost twice as likely to have calcium deposits,
which indicate the onset of atherosclerosis, in the arteries
of their hearts, as those with the smallest WHRs.
And even when other risk factors such as blood
pressure, diabetes and age were taken into account, the link
remained strong.
Professor James de Lemos, who led the research,
said: "Fat that accumulates around your waist seems to be more
biologically active as it secretes inflammatory proteins that
contribute to atherosclerotic plaque build-up, whereas fat around
your hips doesn't appear to increase risk for cardiovascular
disease at all.
"We think the key message for people is to
prevent accumulation of central fat early on in their lives.
"Even a small pot belly puts us at higher risk
when compared to a flat tummy."
Abdominal fat risks
And waist-to-hip ratio was more closely linked
to these early signs of heart disease than either body mass
index (BMI) or waist circumference alone.
BMI is widely used to assess relative body
weight, and is calculated as weight in kilograms divided by
the square of the height in metres.
June Davison, cardiac nurse at the British
Heart Foundation, said: "People who are overweight or obese
have an increased risk of developing heart disease.
"The risks are even higher when fat is mainly
concentrated around the abdomen.
"What's important is that people consider their
body shape as well as their weight.
"Controlling both by eating less and being
more active is an effective way to reduce your risk of heart
and circulatory disease."
Dr Ian Campbell, medical director of charity
Weight Concern, said even just measuring waist circumference
could be useful to assess abdominal fat levels and risks of
disease.
He said: "The beauty of it is that it is simple,
reproducible, and both patients and doctors/nurses can measure
and understand it."
Previous studies have suggested that a waist
circumference of over 35in (88.9cm) for a woman, and 40in (101.6cm)
for a man indicates a high risk of developing diabetes and heart
disease.
Even a waist circumference of 32in (81.3cm)
for a woman, and 37in (94cm) for a man represents a "significant"
raised risk.
