Sleep Apnea May Be Risk Factor for Sudden Cardiac Death, Mayo Clinic Research Concludes

November 10, 2008

NEW ORLEANS - After studying the sleep characteristics of nearly 11,000 adults in an overnight sleep laboratory, Mayo Clinic researchers suggest that obstructive sleep apnea (OSA) - and, in particular, the low nighttime oxygen saturation of the blood it causes - may be a risk factor for sudden cardiac death (SCD).

OSA is a condition that disrupts breathing during sleep and is associated with obesity.

The study identified OSA as one of two traits that contribute to the highest risk of SCD. The other is age - patients who are 60 years old or older.

SCD can happen when the heart's electrical system malfunctions; if treatment - cardiopulmonary resuscitation and defibrillation - is not administered quickly, a person dies.

If further studies validate these findings, OSA would join established risk factors such as smoking, obesity, high cholesterol and high blood pressure. Mayo Clinic cardiologist Apoor Gami, M.D., the lead researcher on the study, presents the findings today at the American Heart Association's Scientific Sessions 2008 in New Orleans.

Significance
Physicians have suspected for years that OSA might be implicated in SCD because of evidence that low oxygen alters the blood vessels in a way that promotes heart disease. This is the first large study to rigorously test the hypothesis, Dr. Gami says.

"Nighttime low oxygen saturation in the blood is an important complication of obstructive sleep apnea," says Virend Somers, M.D., Ph.D., the study's principal investigator. "Our data showed that an average nighttime oxygen saturation of the blood of 93 percent and lowest nighttime saturation of 78 percent strongly predicted SCD, independent of other well-established risk factors, such as high cholesterol. These findings implicate OSA, a relatively common condition, as a novel risk factor for SCD."

Dr. Somers says these early results are relevant to clinical care. He urges physicians to watch for OSA in their heart patients and consider treating severe cases. "It is possible that diagnosing and treating sleep apnea may prove to be an important opportunity to advance our efforts at preventing and treating heart disease," he says.

Obstructive sleep apnea and public health
OSA is a common breathing disorder associated with frequent and repeated instances of upper airway obstruction during sleep. Restless sleep and extremely loud snoring are typical symptoms. Obstruction can be caused by excess tissue in the airway, a large tongue or large tonsils, or nasal passage irregularities that diminish airflow. Obesity is a major cause of the condition. Treatments are available, such as a customized appliance worn during sleep to stabilize tissues.

Given the rising incidence of obesity in children and adults, OSA is also becoming more common, Dr. Somers says. So concerned are major heart physicians' groups about this emerging public health trend that last summer the American Heart Association and the American College of Cardiology issued a joint statement calling for studies probing the link between OSA and SCD, says Dr. Somers. He chaired the committee that wrote the statement.

About the study
The researchers reviewed data from 10,701 consecutive adults who underwent an initial diagnostic sleep laboratory analysis session between 1987 and 2003. During a follow-up period of up to 15 years, researchers assessed cases where patients had sudden cardiac arrest, and either died (SCD) or were resuscitated, in relationship to the presence of OSA and other data, including nighttime levels of oxygen saturation in the blood. Results showed that during an average follow-up of 5.3 years, 142 patients had suffered SCD and either died or were resuscitated.

Collaboration and support
Other researchers from Mayo were Eric Olson, M.D.; Win Shen, M.D.; R. Scott Wright, M.D.; Karla Ballman, Ph.D.; Daniel Howard; Dave Hodge and Regina Herges. The study was funded by grants from the National Institutes of Health and Mayo Foundation for Medical Education and Research.

Mayo Clinic

---

---

	Questions & Answers About Sleep Apnea (100 Questions & Answers) by Sudhansu Chokroverty (Author) Sleep apnea affects more than twelve million Americans, according to the Institute of Health. Whether you're a newly diagnosed patient, or are a friend or relative of someone suffering from sleep apnea, this book offers help. The only text available to provide both the doctor's and patient's views, Questions and Answers About Sleep Apnea gives you authoritative, practical answers to your questions about treatment options and post-treatment quality of life, and provides sources of support. Written by a world famous authority on sleep and sleep disorders, this text is an invaluable resource for anyone coping with the physical and emotional turmoil of sleep apnea.
	Sleep Apnea - Dream Killer by David DeSchoolmeester A deeply personal story of how a Sleep Disorder almost destroyed the author's life. It is a uniquely true story of Sleep Apnea and just how devastating it can be.
	Get It Up! Revealing the Simple Surprising Lifestyle that Causes Migraines, Alzheimer's, Stroke, Glaucoma, Sleep Apnea, Impotence,...and More! by Sydney Ross Singer (Author), Soma Grismaijer (Author) Imagine curing migraines by merely altering a simple lifestyle habit. Even more, imagine this same lifestyle habit, something we take for granted as normal, can also cause Alzheimer's disease, impotence, stroke, glaucoma, sleep apnea, and more. There would finally be hope, real hope, for the countless millions who suffer from these conditions, and for their families and loved ones who suffer with them. It would be a dream come true. Well, the dream has come true! Get It Up! solves the mystery that has eluded scientists for over a century. We now know what migraines are, what causes them, why some people have them, and how they can stop having them. Get It Up! describes how to truly prevent and cure migraines by stopping the cause, as proven by results from the Migraine...
	Sleep, Interrupted: A physician reveals the #1 reason why so many of us are sick and tired by Steven Y. Park MD (Author) Maybe you're stressed out and tired, and have put on a little weight. Or you have persistent pain you and your doctor can't explain. Man or woman, you may be fighting fluctuating hormone levels. Or maybe you snore like a freight train. Anything that narrows the throat and interrupts sleep, particularly breathing problems brought on by sleep position, illness, life changes, or your anatomy, may be key to understanding a host of common health issues. In this groundbreaking book, Dr. Steven Park outlines a simple, rational explanation for what s making you sick, and provides guidance for treatment options that address specific health problems.
	Snoring and Sleep Apnea: Sleep Well, Feel Better by M.D. Ralph A. Pascualy (Author) Snoring and Sleep Apnea is written people with sleep apnea, as well as for their bed partners, families, and friends, and for health care professionals involved in sleep apnea management. Written by experts in the field, the book covers causes, diagnosis, treatment, and surgical techniques as well as the pros and cons of specific therapies. Readers learn when snoring is a sign of sleep apnea, why the condition is dangerous, when to see a sleep specialist, where to find an accredited sleep disorder center, the latest treatments, and how to feel better fast. Fully revised and expanded, this edition also contains a new chapter on women and sleep apnea; managing children and adolescents with the problem; advances in CPAP and other key treatments; and the latest statistics on the impact of...
	Sleep Apnea Symptoms And Treatments by Dr. Frederik Dunssel Have you been experiencing lack of sleep at night and find yourself waking up in the wee hours of the morning to find yourself gasping for air? You have a few more hours to sleep before it's time to get up, but you're having difficulty going back to sleep. You realize that it's only 1:30 in the morning. It is still dark and you are the only one struggling to get some more shut eye. You could possibly be suffering from sleep apnea and not even know it. Sleep apnea is a sleep disorder that causes you to stop breathing for short intervals. This disorder is not easily detected because it happens while you are sleeping. If your condition goes untreated, you can suffer serious medical issues later on. In this guide on Sleep Apnea, you will find out what this sleep disorder...
	Sleep Apnea and CPAP - A User's Manual By a User by Bruce Stein (Author) CPAP and Sleep Apnea - A User's Manual By a User is for individuals who have been diagnosed with sleep apnea and use either CPAP or BiPAP. It is a very practical guide to improve the ease of day to day use including travel. After over 11 years of using BiPAP, the author used his medical and research training and the inventiveness of his profession (patent law) to solve most of the same problems any user encounters which makes the individuals daily use much easier and more therapeutic. You don't have to reinvent the best way to use your equipment, just follow his advice. The very useful topics he covers includes getting the mask to fit properly; preventing the tube from getting caught in the sheets and bedding; improving the method of connecting the mask to the tube to the point it...
	Sleep Apnea - The Phantom of the Night: Overcome sleep apnea syndrome and snoring by T. Scott Johnson (Author), William A. Broughton (Author), Jerry Halberstadt (Author), B. Gail Demko (Author), Carl E. Hunt (Author), William Dement (Author), Colin Sullivan (Author) Sleep apnea disrupts the lives of millions of unsuspecting victims. Their struggle to breathe during sleep is a major cause of daytime sleepiness, accidents, poor health, lost years of productivity and happiness, and even death. Experts in sleep medicine and a patient guide people with snoring and sleep apnea and their families to take advantage of dramatically effective medical treatment. Broughton, the medical director of the accredited University of Alabama Knollwood Sleep Disorders Center, updates current advances. Demko reviews oral appliance therapy. They explain sleep as well as sleep apnea, and show the person with apnea how to recognize it, obtain a diagnosis, treat it, and overcome social, physical, or emotional obstacles to recovery. Coverage of treatments including CPAP,...
	The Quick and Easy Sleep Apnea Book by Gautam Soparkar (Author) If you have sleep apnea, think you might have it, or know someone who does, this book is for you! Sleep apnea is a relatively new subject in health care. It is very common and is associated with many other medical conditions, particularly high blood pressure, heart disease, and strokes. However, awareness about sleep apnea is lacking, and misconceptions are common. It is very easy to pass off the signs and symptoms of sleep apnea. Most people with this condition don’t even know they have it. This is very unfortunate because effective, even life-transforming, treatment is available. The consequences of untreated sleep apnea are wide-ranging and can be devastating. This book is a concise, illustrated, practical, and readable guide to this common and potentially...
	Sleep Apnea and Snoring: Surgical and Non-Surgical Therapy, 1e by Michael Friedman MD (Author) Finally, a multi-disciplinary approach that covers both the surgical and non-surgical interventions for sleep apnea and snoring. From the editor of Operative Techniques in Otolaryngology, this new reference will quickly become the standard in surgery for this key area within otolaryngology. ., Full-color line drawings illustrate key concepts and create a comprehensive way of learning surgical techniques.Provides consistent, templated chapters and a contemporary, full-color format for quick, easy access to the most up-to-date surgical and non surgical interventions for sleep apnea and snoring.Includes contributions from leaders in neurology, pulmonology, psychiatry, otolaryngology, and oral & maxillofacial surgery. to create a truly multi-disciplinary approach.Covers new and innovative...