Obesity has long been identified as a risk factor for cardiovascular disease and heart failure. But, a new study conducted by researchers at the University of Rochester Medical Center found that being skinny confers no advantage when it comes to the risk of dying suddenly from cardiac causes.
Scientists found that non-obese heart failure patients ¨C including overweight, normal and underweight patients ¨C had a 76 percent increase in risk of sudden cardiac death compared to obese heart failure patients. Normal and underweight patients showed a startling 99 percent increase in risk for sudden cardiac death compared to obese patients.
The results were presented today at the American College of Cardiology Annual Scientific Session in Atlanta. The study, by researchers from one of the world¡¯s leading groups on sudden cardiac death, is the first to assess the relation between BMI and the risk of sudden cardiac death.
¡°This study is important because it not only answers questions regarding the risk of sudden cardiac death in different types of heart failure patients, but poses several new questions that need to be explored,¡± said corresponding study author Ilan Goldenberg, M.D., research associate professor of Medicine in the Cardiology Division. ¡°Why do obese heart failure patients see a risk advantage? Why do normal weight patients have a significantly different risk profile than those who are slightly overweight? These are important questions that may have treatment implications in the future.¡±
The researchers at the University¡¯s Heart Research Follow-Up Program examined the risk of sudden cardiac death in 1,231 patients who had suffered at least one prior heart attack and had been diagnosed with a low ejection fraction, a measurement of how much blood is pumped from the heart with each beat. Their analysis found that decreased BMI or body mass index was associated with a large increase in the risk of sudden cardiac death. These findings highlight the ¡°obesity paradox,¡± a phenomenon long recognized by cardiologists that, once afflicted, obese heart failure patients fare better than their slimmer counterparts. This study adds to a growing body of conflicting data regarding the relation of BMI to outcome in patients with heart failure.
¡°When we started this study we were hoping the data would disprove the obesity paradox,¡± said Bonnie Choy, co-lead author and a second year medical student at the University¡¯s School of Medicine and Dentistry. ¡°Our study is the first to create and analyze subcategories within non-obese patients, looking at overweight, normal and underweight patients, but even with this advanced analysis we still the saw an inverse relationship between BMI and sudden cardiac death.¡±
The science behind the obesity paradox in the heart failure population is unresolved, but some researchers believe timing may have something to do with it. One possible explanation is that the long-term negative effects of conventional risk factors, such as increased BMI, may be overwhelmed by the short-term effects of other factors on heart failure mortality. In addition, survival advantages that exist in obese patients with heart failure may, in the short term, outweigh the harmful effects of increased BMI.
¡°Obese patients are hard on their bodies; many don¡¯t eat right, don¡¯t exercise, and many smoke,¡± explained Eric Hansen, co-lead author and also a second year medical student at the University of Rochester. ¡°If their bodies are surviving this bad treatment then perhaps they are better equipped, from a genetic standpoint, to live with heart failure.¡±Compared to the overweight, normal and underweight patients, obese patients were younger, had a higher ejection fraction, higher blood pressure, diabetes and were more likely to be smokers. BMI was calculated as weight in kilograms divided by the square of height in meters for all study participants. The clinical definition of obesity ¨C BMI ¡Ý30 kg/m2 ¨C was used. Overweight patients fell into the 25 to 29 kg/m2 range of BMI values and normal/underweight patients fell into the
In addition to evaluating the relationship between BMI and sudden cardiac death, researchers assessed the effect of BMI on the benefit of implantable cardioverter defibrillator (ICD) therapy. An implantable cardioverter defibrillator is a medical device about the size of a pager that is surgically implanted in the chest under local anesthesia. The device detects irregular and potentially fatal heart rhythms (arrhythmias), which often lead to sudden cardiac death, and shocks the heart back into a normal rhythm. Researchers found that implantable cardioverter defibrillator therapy was more effective in the non-obese patients with lower BMI values who were at higher risk for sudden cardiac death. These findings may help identify patients who would get the most benefit from an ICD ¨C patients with a lower BMI.
Sudden cardiac death claims up to 330,000 American lives every year, accounting for about half of all cardiac deaths. Sudden cardiac arrest, a condition in which the heart suddenly and unexpectedly stops beating, leads to sudden cardiac death if it is not treated within minutes. Most cases of sudden cardiac arrest are due to abnormal heart rhythms that can result from blockage of coronary arteries or scarring from a prior heart attack. Certain drugs can also trigger abnormal rhythms and death.
In addition to Goldenberg, Choy and Hansen worked closely with Cardiology faculty members Arthur J. Moss, M.D., and Wojciech Zareba, M.D., Ph.D., to complete this study.For Media Inquiries:
Emily Butler | EurekAlert!
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences