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!
Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy