Women who are overweight or obese have a significantly higher risk of developing atrial fibrillation than do women with a normal body mass index, and those who gain weight rapidly are at even greater risk, suggesting that weight control may be an effective means of preventing the most common form of arrhythmia, according to a report in the Journal of the American College of Cardiology released May 17.

Among 34,309 women in the Women’s Health Study followed for a mean of nearly 13 years, each 1 kg/m² increase in body mass index was associated with a 4.7% increase in risk for atrial fibrillation (AF). Both overweight (25.0-29.9 kg/m²) and obesity (BMI at least 30 kg/m²) were associated with a significant increase in risk. In an analysis adjusted for multiple variables, women who became obese during the first 5 years of the study had a significant, 41% adjusted increase in risk for developing AF, compared with women who maintained weight below the obese range, say Dr. Usha B. Tedrow and colleagues from the Brigham & Women’s Hospital and Harvard University in Boston and University Hospital in Basel, Switzerland.

The risk of AF for women who became obese in the early years of the study was higher than that for women who were obese at baseline and maintained their weight, the investigators reported.

“If the observed dynamic associations between BMI and AF are causal, the public health impact of the current obesity epidemic on the growing AF burden could be quite substantial with respect to clinical outcomes, quality of life, and health care costs associated with AF,” the authors noted.

The study was designed to explore the potential relationship between two concurrent phenomena: a rapid increase in the prevalence of AF over the last 30 years and the growing obesity epidemic.

They looked at data on 34,309 women who were enrolled in the Women’s Health Study, a large, prospective cohort study. The women were all free from cardiovascular disease at baseline. The investigators reviewed medical records to confirm cases of AF, and compared baseline and updated measures of BMI from periodic questionnaires. They also examined the potential role of inflammatory mediators in AF associated with obesity.

A total of 834 confirmed AF events occurred during the 12.9 mean person-years of follow-up. The investigators determined that BMI had a statistically significant, linear association with AF risk, with each unit of BMI increase – 1 kg/m² – equating to a 4.7% increase in risk. This association held in multivariate analysis that controlled for diabetes, hypertension, age, ethnicity, hyperlipidemia, alcohol use, smoking, and physical activity.

When they looked at the relationship between change in BMI and AF over time, the investigators found that among 2,411 women who became obese in the first 5 years of the study, the hazard ratio (HR) for developing AF was 1.41, compared with women who maintained a BMI in the normal or overweight categories during the same period.

There was also a nonsignificant trend of weight loss appearing to cancel out AF risk, with women who were obese at baseline but dropped below the 30 kg/m² threshold before year 5 having a HR of 1.01.

Potential study limitations, the authors say, included the use of self-report of AF cases, which could miss asymptomatic cases; self-report of body weight, height, and confounding data; and the selection of a cohort of healthy, middle-aged, and largely white women, which may limit the generalizability of the findings to women of other ethnic backgrounds or to men ( J Am Coll Cardiol 2010;55:2319-2).

In an accompanying editorial, Dr. Nikolaos Dagres and Dr. Maria Anastasiou-Nana of the University of Athens, wrote that the study demonstrates “that changes in body weight have a significant influence on the associated AF risk. Considering the predictions for the future development of both obesity and AF prevalence, weight control will probably become an increasingly important strategy, not only for prevention of the well-known adverse health effects associated with obesity, but also for prevention of AF”(J. Am. Coll. Cardiol.2010;55:2328-9).

The study was supported by grants from the Watkins and Harris Family Foundation and the National Heart, Lung and Blood Institute. The Donald W. Reynolds Foundation funded the biomarker measurements. Dr. Tedrow has financial ties with St. Jude Medical and Biosense Webster.

Dr. Dagres and Dr. Anastasiou-Nana did not disclose potential conflicts of interest.

Copyright (c) 2009 Elsevier Global Medical News. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

根据5月17日发表于《美国心脏病学会杂志》( Journal of the American College of Cardiology)上的一项报告，与体重指数正常的女性相比，超重或肥胖的女性发生房颤(AF)的风险明显更高，并且体重迅速增加的女性发生房颤的风险甚至更高，这表明控制体重可能是预防这一最常见心律失常的有效方法。

 

这项女性健康研究对34,309名女性平均随访约13年发现，体重指数每增加1 kg/m²，则发生AF的风险增加4.7%。超重(25.0~29.9 kg/m²) 和肥胖(BMI≥30 kg/m²)均与风险显著增加相关。波士顿哈佛大学布莱根妇女医院和瑞士巴塞尔大学医院的Usha B. Tedrow博士及其同事对多个变量进行校正后分析发现，在研究最初5年内变得肥胖的女性发生AF的风险比体重维持在肥胖水平下的女性显著增加了41%。

 

研究者表示，在研究最初几年内变得肥胖的女性发生AF的风险高于基线时肥胖但能维持体重的女性。

 

作者指出：“如果所观察到的BMI与AF之间的动态关联呈因果性，那么从与AF相关的临床转归、生活质量和医疗费用等方面来看，当前肥胖流行对日益增加的AF负担造成的公共卫生影响将会非常显著。”

 

该研究旨在探讨目前两种现象之间的潜在关系：AF发生率在过去30年迅速增加的现象与肥胖流行日益增加的现象。

 

他们对入组于该女性健康研究(大规模、前瞻性队列研究)的34,309名女性的数据进行了分析。所有女性在基线时均无心血管疾病。研究者通过病历回顾的方式来确诊AF病例，并对来自定期问卷的BMI基线测量值与适时测量值进行了比较。他们还探讨了炎症介质在肥胖相关AF中的潜在作用。

 

在平均12.9人年的随访期间，共发生834件确诊的AF事件。研究者发现，BMI与AF风险之间呈显著线性关联，即BMI每增加1个单位(1 kg/m²)，相当于AF风险增加4.7%。对糖尿病、高血压、年龄、种族、高脂血症、饮酒、吸烟和体力活动等多个因素进行校正后分析发现，这种关联仍然存在。

 

研究者对BMI随时间推移发生的变化与AF之间的关系进行了分析，他们发现，与在研究最初5年内BMI维持正常或超重的女性相比，在这一时期内变得肥胖的2,411名女性发生AF的危险比(HR)为1.41。

 

基线时肥胖但体重指数在第5年之前降至低于30 kg/m²阈值的女性发生AF的HR为1.01，表明体重下降可抵消AF风险，但这没有显著意义。

 

作者表示，该研究的潜在局限性包括使用自我报告的AF病例(这可能会漏掉无症状的病例)；自我报告体重、身高和混杂数据；选择了大部分为白种人的健康中年女性(这可能会限制结果外推至其他种族的女性或男性)( J Am Coll Cardiol 2010;55:2319-2)。

 

雅典大学的Nikolaos Dagres博士和Maria Anastasiou-Nana博士在随刊编者按中写道，该研究显示，“体重变化对相关AF风险具有显著影响。考虑到肥胖和AF发生率在未来的发展情况，控制体重将可能成为日益重要的策略，不仅可用于预防肥胖对健康的已知不良影响，还可用于预防AF。”(J. Am. Coll. Cardiol.2010;55:2328-9)

 

该研究获得沃特金斯与哈里斯家庭基金会及美国国立心肺血液研究所的资金支持。Donald W. Reynolds基金会资助生物标志物的测量。Tedrow博士与St. Jude Medical和Biosense Webster公司存在经济利益关系。

 

Dagres博士和Anastasiou-Nana博士未披露任何潜在经济利害关系。