Obesity paradox: High BMI protective in AF patients using oral anticoagulants
Ghent, Belgium: Increasing BMI is associated with lower mortality, stroke, and systemic embolism risk in atrial fibrillation (AF) patients using oral anticoagulants, a recent study has revealed.
"These seemingly protective effects should still be interpreted with caution as this obesity paradox was driven by results from randomized studies and observational studies rendered more conflicting results," authors wrote in the journal Clinical Cardiology.
Although obesity is associated with the development and progression of AF, there exists an obesity paradox, illustrated by the seemingly protective effects of obesity on AF-related outcomes. Body mass index (BMI) may impact outcomes in AF patients using oral anticoagulants.
Considering the above, The systematic review by Maxim Grymonprez, Ghent University, Ghent, Belgium, and colleagues, aiming to explore this 'obesity paradox', provides an overview of the literature regarding the impact of extreme BMIs on AF-related outcomes.
A meta-analysis investigates the impact of underweight, overweight (BMI 25 to <30 kg/m2),1 obesity, and morbid obesity (BMI ≥40 kg/m2)1 compared to normal BMI on AF-related outcomes in anticoagulated AF patients.
Key findings of the study include:
- After searching Medline and Embase, meta-analysis of results of four randomized and five observational studies demonstrated significantly lower risks of stroke or systemic embolism (RR 0.80; RR 0.63, and RR 0.42 respectively) and all-cause mortality (RR 0.73; RR 0.61; and RR 0.56 respectively) in overweight, obese and morbidly obese anticoagulated AF patients (BMI 25 to <30, ≥30 and ≥40 kg/m2, respectively) compared to normal BMI anticoagulated AF patients (BMI 18.5 to <25 kg/m2).
- In contrast, thromboembolic (RR 1.92) and mortality (RR 3.57) risks were significantly increased in underweight anticoagulated AF patients (BMI <18.5 kg/m2).
- In overweight and obese anticoagulated AF patients, the risks of major bleeding (RR 0.86; and RR 0.88, respectively) and intracranial bleeding (RR 0.75; and RR 0.57 respectively) were also significantly lower compared to normal BMI patients, while similar risks were observed in underweight and morbidly obese patients.
"This meta-analysis demonstrated lower thromboembolic and mortality risks with increasing BMI," wrote the authors. "However, as this paradox was driven by results from randomized studies, while observational studies rendered more conflicting results, these seemingly protective effects should still be interpreted with caution."
The study titled, "The impact of underweight and obesity on outcomes in anticoagulated patients with atrial fibrillation: A systematic review and meta-analysis on the obesity paradox," is published in the journal Clinical Cardiology.