Aug. 14, 2008 -- We know that being overweight or obese can contribute to heart disease and heart attacks, but does extra weight around your belly increase your risk of stroke?
A new study says that may be the case.
Led by Yaroslav Winter, MD, researchers from the University of Heidelberg looked at whether people who were obese or overweight had a greater stroke risk than those who were normal weight. Researchers zoned in specifically on expanding waistlines.
There were 1,137 German adults in the study; 379 of those were stroke patients, and 758 comprised a control group matched for age, gender, and place of residence. The stroke group included 141 women and 238 men, with an average age of 67.
Of the stroke group, 301 had suffered a full-blown stroke, 37 had bleeding in the brain, and 41 experienced what is often called a "mini-stroke" or transient ischemic attack (TIA). A TIA occurs when blood flow to the brain is temporarily blocked and then is spontaneously restored. It's often a precursor to a full stroke and is considered a warning sign.
Obesity was measured using some of the following parameters:
- Waist circumference (measured at the level of the belly button).
- Body mass index (or BMI, defined as body weight in kilograms divided by height in meters squared). A BMI of 30 or greater is considered obese.
Waist-hip ratio (or WHR, defined as waist circumference divided by hip circumference). An abnormal WHR for women is defined as anything greater than or equal to 0.85. For men, an abnormal WHR is anything greater than or equal to 1.0.
Belly Fat and Stroke Risk
Obesity was more common in individuals who had suffered a stroke or TIA, affecting 30% of this group. The BMI, however, was not independently associated with an increased risk of stroke.
The risk association for waist measurements was far more powerful. People with bigger waist circumferences (greater than 40 inches for men and 35 inches for women) had four times the stroke risk when compared with people with typical waistlines. Participants with the highest WHR had nearly eight times the risk of stroke when compared to people with the lowest ratios. These striking results were noted even after adjusting for other risks, like whether participants were inactive, smoked, or had diabetes.
"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," study senior author Tobias Back, MD, at Saxon Hospital Arnsdorf, says in a news release.
Back also calls for doctors to become aware of the waistline connection: "Physicians should measure patients' 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."
In the news release, Back urges people to do all those things we know contribute to good health, "Physical activity was much more common in the controls than in the stroke and TIA patients."
The results are published in Stroke: Journal of the American Heart Association.