WINSTON-SALEM, N.C. -- A new study done by researchers at Wake Forest University School of Medicine shows that social stress could be an important precursor to heart disease by causing the body to deposit more fat in the abdominal cavity, speeding the harmful buildup of plaque in blood vessels, a stepping stone to the number one cause of death in the world.
The findings could be an important consideration in the way the United States and other Western countries try to stem the rapid rise of obesity, said Carol A. Shively, Ph.D., a professor of pathology and the study's principal investigator.
The study appears as the cover story of the current issue of Obesity, the peer-reviewed journal of the Obesity Society.
"We are in the midst of an obesity epidemic," Shively said. "Much of the excess fat in many people who are overweight is located in the abdomen, and that fat behaves differently than fat in other locations. If there's too much, it can have far more harmful effects on health than fat located in other areas."
She notes that obesity is directly related to lower socioeconomic status in Western societies, as is heart disease. So, the people who have fewer resources to buffer themselves from the stresses of life are more likely to experience such health problems, she said.
In this study of how the stress of low social status affects the development of heart disease, female monkeys were fed a Western-style diet containing fat and cholesterol. The monkeys were housed in groups so they would naturally establish a pecking order from dominant to subordinate. Subordinate monkeys are often the target of aggression and aren't included in group grooming sessions as often as dominant monkeys.
Shively and colleagues Thomas C. Register, Ph.D., and Thomas B. Clarkson, D.V.M., all faculty of the Department of Pathology, Section on Comparative Medicine at the School of Medicine, found that these socially stressed subordinate monkeys developed more fat in the viscera, or abdominal cavity.
The researchers found that the stress of social subordination results in the release of stress hormones that promote the deposition of fat in the viscera. Visceral fat, in turn, promotes coronary artery atherosclerosis, the buildup of plaque in the blood vessels that leads to heart disease, the leading cause of death in the world today.
What is striking about that relationship, Shively said, is that women and female monkeys have a natural protection against heart disease – women typically develop heart disease, on average, 10 years later than men do. That protection seems to be lost when stress and visceral fat increase. Researchers found that the monkeys with high social stress and larger amounts of visceral fat also had ovaries that produced fewer protective hormones.
"Suppressed ovarian function is a very serious condition in a woman," Shively said. "Women who are hormone-deficient will develop more atherosclerosis and be at greater risk of developing coronary heart disease and other diseases such as osteoporosis and cognitive impairment."
Women whose bodies are not producing adequate amounts of hormones won't necessarily know it, Shively said. The researchers found that low hormone production doesn't always lead to fewer menstrual cycles. To diagnose serious health problems in obese women, doctors would have to investigate hormone levels.
"We need to take a closer look at the ovarian function of obese women," Shively said. "They might not be producing enough hormones to maintain adequate health."
The study's results also reinforce basic health advice, she said: watch what you eat, exercise regularly, and try to manage the stress in your life.
The study was funded by the National Heart, Lung and Blood Institute of the National Institutes of Health and by a grant from the John D. and Catherine T. MacArthur Foundation.
Media Relations Contacts: Jessica Guenzel, jguenzel@wfubmc.edu, (336) 716-3487; Bonnie Davis, bdavis@wfubmc.edu, (336) 716-4977; or Shannon Koontz, shkoontz@wfubmc.edu, (336) 716-2415.
Wake Forest University Baptist Medical Center (www.wfubmc.edu) is an academic health system comprised of North Carolina Baptist Hospital, Brenner Children's Hospital, Wake Forest University Physicians, and Wake Forest University Health Sciences, which operates the university's School of Medicine and Piedmont Triad Research Park. The system comprises 1,056 acute care, rehabilitation and long-term care beds and has been ranked as one of "America's Best Hospitals" by U.S. News & World Report since 1993.
Researchers urge adoption of lifesaving treatment at more hospitals across the nation
"There are very few treatments for cardiac arrest victims, and hypothermia stands out as the only therapy which can improve neurologic survival," Raina M. Merchant, MD, MS
PHILADELPHIA -- A brain-preserving cooling treatment called therapeutic hypothermia is a cost-effective way to improve outcomes after out-of-hospital cardiac arrest, which claims the lives of more than 300,000 people each year in the United States and leaves thousands of others neurologically devastated. The treatment, which lowers body temperature to prevent damage to the brain and other major organs when blood flow is restored to the body following cardiac arrest, is considered a “good value” when compared to many other accepted and widely utilized medical treatments, including dialysis for kidney failure or complex heart surgeries, according to new University of Pennsylvania School of Medicine research published this week in Circulation: Cardiovascular Quality and Outcomes.
"Having already established that hypothermia improves neurological outcomes after cardiac arrest, we now know that the therapy is also a good use of health care resources," says lead author Raina M. Merchant, MD, MS, an emergency physician and Robert Wood Johnson Clinical Scholar at Penn Medicine. "We hope our findings will help more hospitals and insurers to adopt cooling protocols and help more survivors return to productive lives."
Despite national recommendations established in 2005 calling for out-of-hospital cardiac arrest patients to be treated with hypothermia when they remain comatose after resuscitation, many hospitals still don't offer the intervention. Among barriers to its use: Concerns about its cost, and difficulty coordinating the interdisciplinary resources and staff needed to employ the treatment. Merchant and her colleagues used a complex mathematical design to measure quality-adjusted survival after cardiac arrest, cost of hypothermia equipment and treatment, and cost of post-hospital discharge care. Factors affecting costs included additional nursing care required during cooling treatment, extra time spent in the intensive care unit and post-discharge care required. They found that hypothermia has a cost of less than $100,000 per quality-adjusted life year (QALY), a measurement designed to illustrate the gains in both extra years of life and quality of life from a particular treatment.
Previous research has shown that about six out-of-hospital cardiac arrest patients need to be treated with hypothermia in order for one additional patient to be discharged without the brain damage that characterizes many survivors. Even when the authors of the new study adjusted their model to increase the proportion of neurologically impaired survivors in the group who received hypothermia, results still showed favorable cost-effectiveness estimates for hypothermia.
The findings also revealed that hypothermia treatment is actually less expensive than other interventions that have been implemented to treat cardiac arrest across the United States, including widespread CPR and defibrillation training for the public. In addition, the new research is among few studies to examine the costs of caring for patients who survive cardiac arrest with neurological deficits – a tremendous burden for the health care system and family caregivers.
"There are very few treatments for cardiac arrest victims, and hypothermia stands out as the only therapy which can improve neurologic survival," Merchant says. "Hospitals and physicians should promote rapid adoption of this treatment for patients, and cost should not be considered a barrier to use."
Other authors of the study include Peter W. Groeneveld, MD, MS, Lance B. Becker, MD, Benjamin S. Abella, MD, MPhil, and David A. Asch, MD, MBA. The study was funded by the Robert Wood Johnson Foundation Clinical Scholars Program (Merchant) and a Career Development Transition Award from the Veterans Affairs Health Services research and Development Service (Groeneveld).
PENN Medicine is a $3.6 billion enterprise dedicated to the related missions of medical education, biomedical research, and excellence in patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System.
Penn's School of Medicine is currently ranked #3 in the nation in U.S.News & World Report's survey of top research-oriented medical schools; and, according to the National Institutes of Health, received over $366 million in NIH grants (excluding contracts) in the 2008 fiscal year. Supporting 1,700 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.
The University of Pennsylvania Health System (UPHS) includes its flagship hospital, the Hospital of the University of Pennsylvania, rated one of the nation's top ten "Honor Roll" hospitals by U.S.News & World Report; Pennsylvania Hospital, the nation's first hospital; and Penn Presbyterian Medical Center, named one of the nation's "100 Top Hospitals" for cardiovascular care by Thomson Reuters. In addition UPHS includes a primary-care provider network; a faculty practice plan; home care, hospice, and nursing home; three multispecialty satellite facilities; as well as the Penn Medicine at Rittenhouse campus, which offers comprehensive inpatient rehabilitation facilities and outpatient services in multiple specialties.
At a time when water supplies are scarce in many areas of the United States, scientists in Minnesota are reporting that production of bioethanol -- often regarded as the clean-burning energy source of the future -- may consume up to three times more water than previously thought. Their study appeared in ACS' journal Environmental Science & Technology.
Sangwon Suh and colleagues point out in the study that annual bioethanol production in the U.S. is currently about 9 billion gallons and note that experts expect it to increase in the near future. The growing demand for bioethanol, particularly corn-based ethanol, has sparked significant concerns among researchers about its impact on water availability. Previous studies estimated that a gallon of corn-based bioethanol requires the use of 263 to 784 gallons of water from the farm to the fuel pump. But these estimates failed to account for widely varied regional irrigation practices, the scientists say.
The scientists made a new estimate of bioethanol's impact on the water supply using detailed irrigation data from 41 states. They found that bioethanol's water requirements can be as high as 861 billion gallons of water from the corn field to the fuel pump in 2007. And a gallon of ethanol may require up to over 2,100 gallons of water from farm to fuel pump, depending on the regional irrigation practice in growing corn. However, a dozen states in the Corn Belt consume less than 100 gallons of water per gallon of ethanol, making them better suited for ethanol production. "The results highlight the need to take regional specifics into account when implementing biofuel mandates," the article notes.
ARTICLE #3 FOR IMMEDIATE RELEASE
"Water Embodied in Bioethanol in the United States"
DOWNLOAD FULL TEXT ARTICLE : http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/es8031067
CONTACT:
Sangwon Suh, Ph.D.
Department of Bioproducts and Biosystems Engineering
University of Minnesota
St. Paul, Minn. 55108
Phone: 612-624-5307
Fax: 612-624-3005
Email: sangwon@umn.edu
Risk of death in hospitals was nearly 5 times greater among patients who received blood transfusions
A new study suggests that blood transfusions for hospitalized cardiac patients should be a last resort because they double the risk of infection and increase by four times the risk of death.
The analysis of nearly 25,000 Medicare patients in Michigan also showed that transfusion practices after heart surgery varied substantially among hospitals, a red flag that plays into the health care reform debate.
A wide variation in care is a hot-button issue, as lawmakers and health reform experts discuss the best ways to address the variations. Some experts believe the country needs a system of medical guidelines, supported by scientific evidence, to aid doctors in decision-making. In fact, the Institute of Medicine has called for a national initiative of comparing the benefits and harms of certain methods to improve the delivery of care -- an effort referred to by health-care insiders as "comparative effectiveness" research.
Blood transfusion is an area that could be well served with stronger, research-based guidelines, since the current clinical practice is all over the map, said study co-author Neil Blumberg, M.D., professor of Pathology and Laboratory Medicine and director of Transfusion Medicine at the University of Rochester Medical Center.
"Doctors are simply doing what they were trained to do, but it turns out that their actions are more harmful than helpful in many cases," Blumberg said. "This is an instance in which clinical practice got way ahead of research. And changing the liberal use of transfusions is going to be difficult despite the evidence showing it is usually not essential."
The study was published July 31, 2009 in the journal, BMC Medicine. It was designed to assess patient outcomes as well as hospital variation in blood use.
Blumberg and lead author Mary Rogers, Ph.D., of the University of Michigan Health System, analyzed patient records in 40 hospitals, from admission to 30 days after discharge. All had received coronary artery bypass graft surgery from 2003 to 2006. They found that 30 percent of variation in transfusion practices seemed to be due to widely varied practices among hospital sites.
Also, blood use among women patients ranged from 72.5 percent to 100 percent, and blood use among men varied from about 50 percent to 100 percent. Transfusions with donor blood were associated with infections of the genitourinary system, respiratory tract, bloodstream, digestive tract and skin, the study said.
The risk of death in the hospital was nearly 5 times greater among patients who received a blood transfusion, and the risk of death in the next 30 days was nearly three times greater. Some of the risk may've been due to the underlying condition that led to transfusion but an increasingly convincing body of evidence demonstrates that some of the effect is almost certainly due to the transfusion itself, Blumberg said.
Blood transfusions are extremely common in the United States. Some of the typical reasons for transfusions include prevention of anemia and improving oxygen delivery in heart failure.
Blumberg has been a long-time advocate for fewer transfusions and, when they are necessary, for using blood from which the donor's white cells have been removed. This process, called leukoreduction, is believed to diminish the chances of infection and inflammation, research has shown.
"Blood transfusions are certainly necessary in life-threatening situations," Blumberg said. "But this study and other studies confirm they should be a last resort, not a first resort, as they often are."
For decades the URMC has been a leader in the study of blood transfusions, and Strong Memorial Hospital at URMC was among the first in the country to begin using leukoreduced blood for all its patients.
More recently, a team at Strong began to further refine the guidelines for blood transfusion. As a result the hospital has already seen a 10 to 15 percent drop in transfusions during the past six months. The improvement program is still in its early stages, and Blumberg said they will closely monitor the use of transfusions at Strong in the coming months.
COLD SPRING HARBOR, N.Y. -- Vectors derived from retroviruses are useful tools for long-term gene transfer because they allow stable integration of transgenes and propagation into daughter cells. Lentiviral vectors are preferred because they can transduce non-proliferating cellular targets. These vectors can be engineered to target specific tissues. In the August issue of Cold Spring Harbor Protocols (www.cshprotocols.org/TOCs/toc8_09.dtl), François-Loïc Cosset and colleagues from Ecole Normale Supérieure de Lyon (http://hvd.ens-lyon.fr/human_virology_dpt) present a method for targeting hematopoietic stem cells using engineered viral vectors.
The article, "Hematopoietic Stem Cell Targeting with Surface-Engineered Lentiviral Vectors," is freely available on the website for Cold Spring Harbor Protocols (http://cshprotocols.cshlp.org/cgi/content/full/2009/8/pdb.prot5276).
Though viral vectors are highly efficient, their use can raise concerns about recombination, immune responses and other safety issues. DNA transposons offer an effective, alternative method for nonviral gene transfer that avoids the safety concerns associated with viral vectors. Use of the "Sleeping Beauty Transposon System for Stable Gene Expression in Mouse Embryonic Stem Cells" from Catherine Krull and colleagues at the University of Michigan (http://www.med.umich.edu/cdb/sub_pages/People/krull.htm) provides a method for stable integration and reliable long-term expression of a transgene. Sleeping Beauty transposon-based transfection is a two-component system consisting of a transposase and a transposon containing inverted repeat/direct repeat sequences that result in precise integration into a TA dinucleotide. The article is freely accessible on the website for Cold Spring Harbor Protocols (http://cshprotocols.cshlp.org/cgi/content/full/2009/8/pdb.prot5270).
About Cold Spring Harbor Protocols: Cold Spring Harbor Protocols (www.cshprotocols.org) is a monthly peer-reviewed journal of methods used in a wide range of biology laboratories. It is structured to be highly interactive, with each protocol cross-linked to related methods, descriptive information panels, and illustrative material to maximize the total information available to investigators. Each protocol is clearly presented and designed for easy use at the bench—complete with reagents, equipment, and recipe lists. Life science researchers can access the entire collection via institutional site licenses, and can add their suggestions and comments to further refine the techniques.
About Cold Spring Harbor Laboratory Press: Cold Spring Harbor Laboratory Press is an internationally renowned publisher of books, journals, and electronic media, located on Long Island, New York. Since 1933, it has furthered the advance and spread of scientific knowledge in all areas of genetics and molecular biology, including cancer biology, plant science, bioinformatics, and neurobiology. It is a division of Cold Spring Harbor Laboratory, an innovator in life science research and the education of scientists, students, and the public. For more information, visit www.cshlpress.com.