Obesity and Sleep Apnea: What's the Connection?

by Jeffrey Heit, M.D. Health Professional

Sleep apnea is a dangerous and growing problem in the U.S. It is also inextricably related to the epidemic of obesity. Simply put, sleep apnea is a disorder in which one's airway becomes obstructed while asleep, causing loud snoring in its most benign form to a complete cessation of breathing, cardiac arrhythmias and low blood oxygen levels at its worst. The repeated episodes of apnea (lack of breathing) cause frequent nighttime awakening (thought the patient is often unaware) and hence broken, choppy, non restorative sleep. The problem is usually first noticed by the patient's spouse or partner, who is disturbed by the patient's loud snoring and/or apneic episodes.

Individuals with the disorder often complain of morning headaches, constant fatigue, listlessness and moodiness. They can fall asleep almost anywhere. These are the people who easily fall asleep watching television, a movie, or just sitting at a red light. More seriously, they can fall asleep while driving. Obstructive sleep apnea is much more common in obese individuals. It is believed that the airway of the obese individual becomes obstructed by large tonsils, enlarged tongue and increased fat in the neck, all pressing on the airway when the pharyngeal (throat) muscles are relaxed with sleep. A person's neck circumference is a good predictor of sleep apnea. Obese men with a neck circumference of 17 inches or greater, and women with a neck circumference of 16 inches or greater are more likely to have sleep apnea. One study which looked at NFL lineman pointed to a very high incidence of sleep apnea.

The worst part of this is that not only does obesity have an association with sleep apnea, but sleep apnea as well as resultant poor sleep, tends to cause people to eat more. There seems to be a relationship between hunger and satiety hormones and sleep deprivation, though the exact nature of this relationship is unclear. Also, individuals with sleep apnea often have elevated blood pressure, fasting glucose, and high cholesterol, all of which can be made worse with sleep deprivation. So, it's a vicious cycle. Obesity, especially morbid obesity (BMI > 40), can lead to sleep apnea, which, itself, then causes derangements of hormones that control eating habits, leading to more weight gain, worsened blood pressure, glucose intolerance, worsened apnea and the cycle goes on and on.

If you are concerned that you may have sleep apnea, talk to your doctor. Often a sleep study can be performed at a sleep lab. Basically, you spend the night sleeping under observation with oxygen saturation monitors and apnea monitors in place to observe your sleep structure and determine whether you in fact have the disorder. Treatment involves wearing a CPAP (Constant Positive Airway Pressure) mask apparatus at night, which, as the name suggests, props the airway open with positive air pressure generated from an attached machine. Of course a strict regimen of healthy eating, weight loss and exercise is imperative to try and correct the underlying cause.

Jeffrey Heit, M.D.
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Jeffrey Heit, M.D.

Jeffrey Heit is an internist in Burlington, Massachusetts and is affiliated with Philadelphia Veterans Affairs Medical Center. He wrote for HealthCentral as a health professional for Obesity.