MUNICH – Obesity is a strong predictor of atrial fibrillation in otherwise healthy fertile women, according to an analysis of a nationwide Danish registry.
The findings showed that obese women had a twofold increase in the risk of developing atrial fibrillation, compared with healthy-weight women. The risk nearly tripled in very obese women.
"This is just one more study to show that obesity is bad," said Dr. Miguel Quinones, the 2013 American College of Cardiology meeting chair, who was not involved in the study. He added that the study presented very strong data.
Dr. Deniz Karasoy
Previous studies have shown that obesity increases the risk of new-onset AF in patients with known risk factors, such as genetic predisposition, obstructive sleep apnea, and inflammation, said the authors. The study sheds light on yet another population where obesity increases the risk of AF, and it applies to a broader population, said Dr. Deniz Karasoy, who presented the study.
"Previous studies conducted on individuals with established risk factors for developing atrial fibrillation have demonstrated higher relative risk of new-onset AF in men compared to women," he said, in an interview. "Although we have not examined this specific association, we believe that this association is also valid regarding the obese men."
Obesity and atrial fibrillation are among the largest public health related challenges in the Western world, according to the authors.
Dr. Karasoy predicted an increasing prevalence of atrial fibrillation, and in more resistant forms, due to the increasing prevalence of obesity worldwide.
To slow the trend, pervasive primary prevention efforts, such as strategies that would promote weight loss, are needed, said Dr. Karasoy, a research fellow at Cardiovascular Research Center Gentofte, in Denmark.
The study was based on nationwide registry of about 271,000 healthy Danish women, between the ages of 20 and 50 years, who had given birth during 2004-2009.
The women were followed for an average of 4.6 years. Researchers broke down the cohort to five groups: underweight (body mass index below 18.5 kg/m2); normal weight (BMI of 18.5-25); overweight (BMI: 25-30); obese (BMI: 30-35); and extremely obese (BMI greater than 35).
During this period, researchers identified 110 new cases of AF.
Overall AF incidence rate was 9.3 per 100,000 person-years. For normal weight, overweight, obese and very obese women, AF incidence rates were 7.4, 8.5, 15.8, and 27.3 per 100,000 person-years, respectively.
After adjustment for age, comorbidity, medication and smoking, the results showed that obese women had a twofold increase in the risk of developing AF, compared with healthy weight women (hazard ratio, 2.04). That risk more than tripled in very obese women (HR, 3.50). No significant risk increase was observed in the overweight group.
The study did not address obesity’s mechanism of action on atrial fibrillation.
Dr. Karasoy and Dr. Quinones said that they had no relevant disclosures.