Online newspaper of professor Yasser Metwally

*TIA indicates transient ischemic attack.

There was a trend for women to be more strongly affected, with greater risk from increasing waist-to-hip ratios and waist circumference, they note, a trend that requires further investigation.

“The redefinition of obesity based on the waist-to-hip ratio or waist circumference instead of BMI increases considerably the estimate of cerebrovascular events attributable to obesity,” the researchers conclude. “Waist circumference and related ratios, such as waist-to-hip ratio and waist-to-stature ratio, can better predict cerebrovascular events than BMI in a population of central Western Europe.”

In a statement from the American Heart Association, senior author Tobias Back, MD, from Saxon Hospital Arnsdorf in Arnsdorf/Dresden, Germany, said that 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.”

The study was funded by the German Ministry of Education and Research and the National Genome Research Network. The study authors have disclosed no relevant financial relationships.

Stroke. Published online August 14, 2008.

• Clinical Context

The obesity epidemic has had a dramatic, global effect on public health. Although obesity clearly increases the risk for cardiovascular disease, the relationship between increased relative body weight and stroke risk is controversial.

Some, but not all, studies have shown that increasing BMI is associated with a graded elevated risk for stroke. In large-scale, prospective studies, waist circumference vs BMI has been shown to be a better predictor of cardiovascular risk. Markers of abdominal adiposity have seldom been studied in cerebrovascular disease.

• Study Highlights

  1. This case-control study was performed within a well-defined population of central Western Europe.

  2. The objective of the study was to assess the contribution of obesity and abdominal fat mass to the risk for stroke and TIA.

  3. Consecutive cases of patients with ischemic stroke, intracerebral hemorrhage, or TIAs were recruited from a German hospital between February 1, 2005, and January 31, 2006.

  4. Participants with previous cerebrovascular events were not excluded.

  5. Of 1137 participants recruited for this study, 379 were case patients with stroke or TIA, and 758 were control subjects matched for age and sex.

  6. Of the case patients, 37.2% were women.

  7. Mean age of the control subjects was slightly younger than the age of the case patients (65.0 ± 8.3 years vs 67.3 ± 12.2 years; P = .02) because none of the control subjects were older than 75 years.

  8. Conditional logistic regression was used to determine associations between different markers of obesity and the risk for stroke or TIA, after adjustment for other risk factors.

  9. Measures of obesity included BMI, waist-to-hip ratio, waist circumference, and waist-to-stature ratio.

  10. Although BMI was positively associated with cerebrovascular risk, this association was no longer significant after adjustment for physical inactivity, smoking, hypertension, and diabetes (OR for the highest vs the lowest tertile, 1.18; 95% CI, 0.77 – 1.79).

  11. In contrast, markers of abdominal adiposity were strongly associated with the risk for stroke or TIA.

  12. Of the obesity markers studied, the waist-to-hip ratio was the best predictor of the risk for stroke or TIA.

  13. Adjusted ORs for every successive tertile of waist-to-hip ratio were greater vs the previous OR (OR for second tertile, 2.78; 95% CI, 1.57 – 4.91 and OR for third tertile, 7.69; 95% CI, 4.53 – 13.03).

  14. Waist circumference and waist-to-stature ratio were also significantly associated with the risk for stroke or TIA (adjusted OR for the highest vs the lowest tertile, 4.25; 95% CI, 2.65 – 6.84 and OR 4.67; 95% CI, 2.82 – 7.73, respectively).

  15. There was a strong and graded association of abdominal fat markers with the risk for ischemic and hemorrhagic stroke or TIA for both men and women.

  16. The investigators concluded that markers of abdominal adiposity showed a graded and significant association with the risk for stroke or TIA, independent of other vascular risk factors, and that waist circumference and related ratios vs BMI could better predict cerebrovascular events.

  17. Limitations of the study include failure to recruit very old patients or patients with very severe strokes or global aphasia, control subjects only aged 45 to 75 years, participants of the European Prospective Investigation into Cancer and Nutrition study above average concerning their health-oriented lifestyle, number of patients with intracerebral hemorrhage or TIA too small for a detailed subgroup analysis, and lack of data concerning dietary variables.

• Pearls for Practice

  1. In this case-control study, the association of BMI with cerebrovascular risk was not significant after adjustment for other risk factors. Of the obesity markers studied, the waist-to-hip ratio was the best predictor of the risk for stroke or TIA.

  2. Other markers of abdominal adiposity, namely waist circumference and waist-to-stature ratio, were also significantly associated with the risk for stroke or TIA. There was a strong and graded association of abdominal fat markers with the risk for ischemic and hemorrhagic stroke or TIA for both men and women.