December 12, 2019
By Lisa Ferreira, MD
What Is Obstructive Sleep Apnea?
Obstructive sleep apnea (OSA) is an increasingly common condition which affects approximately 20 to 30% of men and 10 to 15% of women in the United States. OSA is a potentially life-threatening sleep disorder in which breathing significantly decreases or stops during sleep. This is often because of a collapse of the airway. The evaluation for OSA is often started when a patient presents to his or her healthcare provider with a concern of increased fatigue. Common complaints from patients who have OSA also include feeling tired when waking despite a full night’s sleep or falling asleep easily during inactive times such as being a passenger in a car or watching television. Other common symptoms include poor concentration, headaches when waking in the morning, and moodiness. The evaluation to diagnose OSA usually starts with a questionnaire called the Epworth Sleepiness Scale or the Stop-Bang Questionnaire. If an assessment such as these is positive or if a healthcare provider is suspicious of this diagnosis, a home sleep apnea test or an overnight in-lab sleep study is performed.
How Does Obesity Contribute to OSA?
Obesity is a well-known risk factor for developing OSA. The prevalence of OSA in men and women increases as the body mass index (BMI), neck circumference, or waist-to-hip ratio increases. Not only does OSA present in adults with obesity, but children with obesity are 46% more likely to have OSA than their normal-weight peers. OSA most often results from a collapse in the upper airway (UA) leading to decreased airflow to the lungs. This collapse of the UA can happen for a few reasons, but, in obesity specifically, the thickness of the soft tissues of the neck can increase pressure on the pharynx.
Can You Get Rid of OSA by Losing Weight?
The initial treatment for OSA always includes an emphasis on weight loss. It has been shown in numerous studies that even losing 10% of your body weight can result in a 20% improvement in OSA symptoms. One study of 72 patients with obesity found that with a weight loss of approximately 20 pounds, the number of events per hour decreased by an average of 4 (Tuomilehto HP, et al, Am J Respir Crit Care Med. 2009;179(4):320). In addition, weight loss through healthy diet and exercise has been shown to improve your overall health and quality of life, improve your blood pressure, and decrease the feeling of sleepiness during the day.
Exercise alone, even without significant weight loss, can also modestly improve the symptoms of OSA. A meta-analysis of five small studies in 2014 showed that participating in a supervised exercise program could improve the number of apneic events per hour in addition to the quality of sleep and symptoms of daytime sleepiness (Iftikhar IH, et al. Lung. 2014:192(1):175).
Numerous studies have shown weight loss from bariatric surgery can result in similar improvements in the symptoms of OSA. One study compared the number of events per hour in patients with moderate to severe OSA when weight loss resulted from laparoscopic adjustable gastric banding (LAGB) versus weight loss from healthy diet and exercise. In both groups of people, the number of apneic episodes decreased between 25 and 35%. The study also showed improvement in the quality of life, daytime fatigue, and depression (Dixon JB, et al, JAMA. 2012 Sep;308(11):1142-9).
Unfortunately, while studies conclusively show an improvement in symptoms associated with OSA, they do not reliably show that OSA can be completely cured by weight loss alone. The chance of cure is higher, however, if the OSA is classified as mild or moderate versus severe. Researchers have also looked at the various bariatric surgery procedures to see if any specific procedure resulted in a higher rate of cure for OSA. The results showed that all patients in the study, regardless of the bariatric procedure, had similar rates of cure even if the amount of weight loss was different (Sarkhosh K, et. al. Obes Surg. 2013 Mar:23(3):414-23). Even though cure of OSA is not guaranteed with weight loss, the improvement in quality of life and the decrease number of apneic events are among the many reasons to focus on weight loss.
Once weight loss is achieved and the symptoms of OSA have shown improvement, maintaining weight loss becomes just as important. It would make sense that if weight loss can improve symptoms, then weight gain can worsen them. This is often true however, interestingly, studies which have looked at the follow up years later on the improvement of OSA symptoms with weight loss have shown that the benefit achieved from the initial weight loss can persist for several years even after up to a 50% regain in weight.
There is no question that weight loss, whether achieved through diet changes, exercise or bariatric surgery, has numerous health benefits. These benefits include the reduction or possible cure of obstructive sleep apnea, enhanced quality of sleep, less daytime sleepiness and improved mood, just to name a few. It is always advisable to talk with your healthcare provider for assistance with the diagnosis and treatment of OSA.