No evidence of obesity paradox in stroke patients

There is no evidence of an ‘obesity paradox’ in patients with stroke, according to researchers from the Danish Cancer Society Research Center, Copenhagen, Denmark. Although obesity often is associated with increased health related complications and death, some studies have suggested an obesity paradox that may cause some to question striving for a normal weight.

However, this latest research published in JAMA Neurology, found no evidence of an obesity paradox in patients with stroke. The reported that stroke occurred at a significantly younger age in patients with higher BMI.

“This study was unable to confirm the existence of an obesity paradox in stroke,” said Dr Christian Dehlendorff of the Danish Cancer Society Research Center, and co-author of the study. “Obesity was not associated with a lower risk for death after a stroke. The risk of obese patients with stroke for death did not differ from that of normal-weight patients with stroke nor was there evidence of a survival advantage associated with being overweight.”

The authors sought to determine whether the obesity paradox in stroke was real or an artificial finding because of selection bias in studies. To overcome selection bias, authors only studied deaths caused by the index stroke using a Danish register of stroke and a registry of deaths. The study included 71,617 Danes for whom information was available on factors that included BMI, age, stroke type and stroke severity.

Of the 71,617 patients, 7,878 (11 percent) died within the first month and, of these, stroke was reported as the cause of death of 5,512 patients (70 percent). Of the patients for whom BMI information was available, 9.7 percent were underweight, 39 percent were normal weight, 34.5 percent were overweight and 16.8 percent were obese. BMI was inversely related to average age of stroke onset (high BMI associated with younger age of onset, p<0.001).

There was no difference in the risk for death by stroke in the first month among patients who were normal weight (reference), overweight (hazard ratio, 0.96; 95% CI, 0.88-1.04), and obese (hazard ratio, 1.0; 95% CI, 0.88-1.13). Analysis of deaths within one week gave similar results.