Inside TC: Asleep on the Job
Published in Inside - Volume V, No. 10
Okay, so I snore. Nobody has to know. Until now, that is. And why, you ask, should you care if I snore? Because my snoring has contributed to TC's research on sleep being done by Assistant Professor Jason Mateika in the Movement Sciences and Education program.
It all started with an e-mail from Mateika informing me, an editor of Inside TC, about his research.
He told me that he and a graduate student (Greg Gates) and a science teacher (Lissette Gonzalez-Perez) are involved in an eight-week summer internship sponsored by the American Physiological Society to examine whether or not the mental and physical consequences of snoring are similar to those reported for people with obstructive sleep apnea.
Obstructive sleep apnea occurs when the airway becomes blocked by the relaxed soft tissue in the throat and breathing stops for an abnormally long period. Mateika said that when people with sleep apnea experience a breathing obstruction during sleep, their oxygen levels can drop as low as 70 percent. Normal oxygen levels are 96 to 100 percent.
People with sleep apnea arouse during sleep more often than non-apneic individuals. These frequent nighttime arousals can, over time, lead to severe sleep deprivation, which may impair cognitive function and physical performance. Similarly, the repeated exposure to low levels of oxygen in the blood at night may also affect cognitive function during the day. Mateika said that "People with sleep apnea can be sitting in a chair working and just fall asleep."
As mentioned, Mateika is currently studying people who snore but don't have sleep apnea to determine differences in sleep behavior and physical functions they might exhibit when compared to people who don't snore. The study they are currently completing examines the link between snoring and cardiorespiratory function and is funded by the American Heart Association and American Lung Association. "With snoring, people may not experience a significant drop in oxygen levels, but they may be constantly aroused from sleep because of the snoring," Mateika explained. A previous study he completed showed that snoring individuals have reduced quality sleep, possibly leading to reduced mental performance during the day.
These findings are also of potential importance in children. The daytime performance of children who snore, usually because of enlarged tonsils and adenoids, may be affected since recent studies link behavioral problems or poor classroom performance to reduced quality of sleep.
So, how does one go about finding people who snore when conducting a study like this? "We post flyers around the Morningside Heights area that say we are looking for subjects between the ages of 20 and 45 who snore," Mateika said. "Or if you know anyone who snores who would like to be part of this study, tell them to get in touch with me."
The next thing I knew I had agreed to be a participant in the study. Apparently it is not easy to find women who snore in that age group.
About a week before the research began, I went up to the lab to "try on" some of the equipment and see what I could expect.
My first night at the sleep lab, Susan, a research assistant, took my blood pressure and EKG for a wakeful baseline reading. Blood pressure, she told me, goes down when you sleep. In non-snorers it goes down substantially. For those of us who snore, however, it goes up and down as we snore, and can sometimes register as a relatively high overall reading for the night.
Subsequently, she measured my head from ear to ear and from my eyebrows to the back of my skull, making marks on my scalp with blue crayon to indicate where surface electrodes would be pasted.
EKG electrodes were attached to my torso and chest. Electrodes were attached to my face near my eyes for an oculogram (eye movement measurement) and on my chin for a myogram (measuring muscle activity). These measures would indicate when I entered NREM (non-rapid eye movement) and REM (rapid eye movement) sleep. REM is a stage of sleep that is characterized by rapid movement of the eyes from side to side and decreases in muscle tone. This is also the stage of sleep in which dreams occur.
Sensors were connected to my legs just below each knee to record leg twitching. A microphone was taped to my neck to record the sound of my snoring. Plastic tubing was placed inside my nostrils to measure airflow, which allowed Susan to determine if my breathing became obstructed. Finally, before I got into the bed, she wrapped bands around my chest and abdomen that would measure my breathing pattern.
All these wires were connected to a box that, once I was lying in the bed, were connected to the monitors in the laboratory next door. In the bedroom, a video camera recorded my every move. A small plastic tube was placed around one finger on my left hand and, when it was activated, throbbed with my pulse, measuring blood pressure. On my right hand, a small plastic clip on my index finger indicated my oxygen level.
When she finally turned out the lights at 11:30 p.m., I was asleep in one minute's time. When I awoke at 5:15 a.m., Susan detached the wires from my body. Four straight hours of snoring was a good session, she said.
The second night, a week later, was the same routine, though my sleep was more restless. When I got up that morning, I was given a graduation present-a CPAP (Continuous Positive Airway Pressure) machine that would prevent me from snoring in the last session. After demonstrating how to use it, Susan gave me the CPAP machine to practice using at home each night so that I could gradually use it for five or six hours straight.
A clear plastic shield covered my nose regulating the airflow in and out of my nose. If I opened my mouth, air came rushing out. When I blew air out of my nostrils, there was resistance.
Susan said I slept more than five hours that third night, but I felt like I had hardly slept at all (and I looked it the next morning). Although I had trouble getting used to the CPAP, Susan told me that many people couldn't sleep without it.
Overall, it was a good experience. The information this study provided would have cost me around $1,200 if I had not been a research subject. In fact, the subjects who complete the entire study for Mateika are compensated for their participation.
So far, Mateika found that snorers who do not experience obstructive sleep apnea show wild swings in blood pressure and elevations in heart rate during sleep compared to normal. These alterations may lead to nighttime cardiovascular events (such as strokes or heart attacks) or daytime hypertension. He also found that elimination of snoring with CPAP reduces variation in blood pressure and decreases heart rate closer to normal levels.
In the future, Mateika will examine how sleep deprivation induced by snoring impacts health and mental performance in both adults and children.previous page