According to the study, to be published in the October 15 issue of the American Journal of Respiratory and Critical Care Medicine, an official publication of the American Thoracic Society, excess weight increased the severity of oxygen desaturation in the blood of individuals with SDB during and after apneas and hypopneas.
"We knew that excess body weight is strongly related to more frequent breathing events—apneas and hypopneas—in persons with SDB," said lead author Paul E. Peppard, Ph.D., assistant professor of population health sciences at the University of Wisconsin-Madison. "In this study, we wanted to go a step further and measure how much the excess weight contributes to the severity of individual breathing events."
Dr. Peppard and colleagues recruited 750 adults from the Wisconsin Sleep Cohort study, an ongoing epidemiological investigation into the natural history of SDB, to have their breathing, blood-oxygen levels and sleep analyzed. Participants were also evaluated on several measures of physique—body mass index (BMI), neck -circumference and waist-to-hip ratio.
Among the participants in the overnight study, 40 percent of whom were obese, there were more than 37,000 SDB events. The researchers found that a number of factors influenced the severity of blood oxygen desaturation associated with these events, including age, gender, body position and sleep phase (REM or non-REM sleep). However, even after these other factors were accounted for, the researchers found that BMI predicted the degree to which the body's tissues were "starved" of oxygen during apneas and hypopneas. In fact, each 10-point increase in BMI predicted a 10 percent increase in the severity of oxygen depletion associated with SDB events.
"This means that if, for example, a six-foot tall, 160-pound 45-year-old man (BMI= 22), had an apnea that produced a six-percent reduction in oxygen saturation, then a man with the same characteristics who weighed 235 pounds (BMI=32) would be expected to have a 6.6 percent reduction in blood oxygen saturation during a similar event," explained Dr. Peppard. "This increased risk of more severe oxygen desaturation is not just associated with clinical obesity—any increase in weight above a BMI of approximately 25 appears to increase the risk and severity of SDB," he noted.
Mary Morrell, Ph.D., from the Imperial College London, who collaborated on the study, pointed out that of all the factors found to influence the severity of oxygen desaturation, being overweight is one of the only factors that is modifiable, suggesting it as a logical target for SDB interventions.
"These results reinforce the importance of excess weight as a risk factor for the development, progression and severity of SDB," said Dr. Peppard. "Clinicians should consider the possibility that particularly overweight patients might be experiencing severer consequences of SDB even if they have the same number of breathing events as less overweight patients."
While these findings represent an important step in understanding the consequences and risk factors associated with excess weight and SDB, Dr. Peppard emphasizes that more research is required to fully understand the issue. "Ongoing studies are looking into how, and to what degree, repeated oxygen desaturations produce poor clinical outcomes," he said. "We also need to assess the impact of the obesity epidemic on sleep apnea prevalence and severity in the general population. Our research group—the Wisconsin Sleep Cohort Study—is presently working on the latter question. Multiple research groups spanning basic science to population-level sciences are working on the former."
Keely Savoie | EurekAlert!
'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers
16.02.2018 | National University of Science and Technology MISIS
New process allows tailor-made malaria research
16.02.2018 | Eberhard Karls Universität Tübingen
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy