SAN FRANCISCO—Obese patients have a higher risk of bleeding while taking warfarin than patients of normal weight, according to research presented at the ATVB/PVD 2015 Scientific Sessions.
In a study of more than 800 patients taking the anticoagulant, obese individuals were almost twice as likely as normal-weight individuals to experience a major bleed.
And patients in the highest obesity class had the greatest risk of bleeding.
Adedotun A. Ogunsua, MD, of the University of Massachusetts Medical School in Worcester, presented these findings at the meeting as abstract 388.
He and his colleagues analyzed 863 patients taking warfarin. The researchers divided patients according to their body mass index (BMI) and looked at the rate of abnormal bleeding, including major gastrointestinal and brain bleeds and minor bleeds.
According to BMI, 21% of the patients were of normal weight, 38% were overweight, and 41.3% were obese, including class I (21%), class II (9%), and class III (11.3%).
Overall, 8.2% of patients (n=71) had abnormal bleeding during the study. Among the reported bleeds, about a third (35.2%) were major and two-thirds (64.8%) were minor.
Multivariable analyses showed that obesity (having a BMI higher than 30) significantly increased the risk of having a major bleed. The hazard ratio was 1.84 (P<0.001).
In univariate analyses, the risk of major bleeding increased with higher obesity categories. The hazard ratios were 1.30 for class I, 1.85 for class II, and 1.93 for class III.
The researchers said these results do not suggest patients should stop taking warfarin because of their weight. However, future studies are needed to understand why obesity increases the bleeding risk for patients receiving warfarin and whether similar risks exist for other anticoagulants.
