Large Waistline
Linked To Stroke Risk
Reported
August 26, 2008
An expanding waistline — already known to increase the
risk of cardiovascular disease — may also increase risk for stroke and
transient ischemic attacks (TIAs), researchers reported in Stroke: Journal
of the American Heart Association.
A TIA is a “warning stroke” that produces stroke-like symptoms but no
lasting damage. Recognizing and treating TIAs can reduce the risk of a major
stroke.
In a case-controlled study of 1,137 German adults, measures of abdominal
adiposity were strongly associated with the risk of stroke/TIA. Those with
the highest waist-to-hip ratio (WHR) had 7.69 times the risk of
cerebrovascular disease compared to those with the lowest WHR, even after
adjustment for other risk factors.
Increased waist circumference and waist-to-stature ratio (WSR), also showed
a strong association, with a 4.25 times risk of stroke and TIA, after risk
adjustments.
The study showed that markers of abdominal adiposity are better predictors
of cerebrovascular events than body mass index (BMI). An initial association
between high BMI and increased risk of stroke became non-significant after
adjustment for other risk factors such as physical inactivity, smoking, high
blood pressure and diabetes, researchers said.
“Obesity is an increasing problem with 66 percent of the adults in the
United States being overweight or obese,” said Tobias Back, M.D., senior
author of the study and director of the Department of Neurology at Saxon
Hospital Arnsdorf in Arnsdorf/Dresden, Germany. “In Germany, 50 percent of
the adult population is overweight. While gaining too much weight can
present health risks, it’s even more dangerous to have the abdominal type of
obesity. People should measure their waistline from time to time and avoid
the accumulation of abdominal fat.”
The study included 379 participants (average age 66 years) who had
previously had a stroke or TIA and 758 age- and sex-matched regional
controls.
Patients received a complete diagnostic work-up. Obesity was measured by
BMI; waist circumference; WHR, defined as waist divided by hip
circumference; and WSR, where the waist circumference is divided by body
height.
“If the waist-to-hip ratio values were greater than .97
for men and .84 for women, then individuals faced almost eight times
increased risk for stroke compared to individuals with a WHR less than 0.92
in men or less than 0.78 in women,” Back said.
If the waist circumference was greater than 40.2 inches for men or 34.6
inches for women, the risk of stroke increased about four times compared to
individuals with normal waistline measures.
“By using different statistical approaches, it was confirmed that
waist-to-hip ratio appeared to be the strongest predictor of stroke and TIA
risk,” Back said.
The researchers also found a trend towards a gender specific effect. The
risk of stroke or TIA was lower in men with abdominal fat than in women with
abdominal fat. “The risk was nearly double in women,” Back said. “This was a
strong trend, but not statistically significant and will require further
research.
“Physicians should measure patient’s waistlines and use the waist-to-hip
ratio to estimate stroke risk. World Health Organization-defined categories
of WHR or waist circumference should be used. Doctors should also consider
the whole vascular risk profile to minimize or modify all possible factors
contributing to coronary heart disease, stroke and peripheral artery
disease.”
Back advised individuals to be physically active, avoid smoking and eat a
healthy diet. “Physical activity was much more common in the controls than
in the stroke and TIA patients,” he said. “For example, a Mediterranean diet
containing fish and olive oil can lower your risk of coronary heart disease
and possibly also lower stroke risk.”
Back said clinical research into therapeutic interventions is needed. “We
urgently need trials to test the effect of weight loss on vascular risk
profiles, especially on the risk of stroke.”
