CASE 1 Mr. M, age 59, has diabetes, hypertension, hyperlipidemia, and obesity, with a body mass index (BMI) of 37 kg/m2. His hyperlipidemia is well controlled with atorvastatin. He also takes hydrochlorothiazide, lisinopril, metformin, and glyburide, but neither his hypertension nor his glucose levels are well controlled. Mr. M does not exercise, and acknowledges eating a high-calorie diet.
Mr. M reports that his wife has begun complaining about his loud snoring, and that he’s been falling asleep at work. He says he has 2 to 3 alcoholic drinks per week, and doesn’t smoke or take any other drugs.
CASE 2 Ms. C, age 35, is seeking treatment for early morning headaches that began several months ago. She describes a constant dull pain over the frontal area that occurs almost every day and typically resolves in 2 to 3 hours. The pain is not affected by postural changes, she says.
She also reports fatigue, daytime sleepiness, and anxiety. Ms. C has a normal BMI (24 kg/m2), takes no medication, and has no prior history of migraine or tension headaches. She denies any alcohol or recreational drug use.
If Mr. M and Ms. C were your patients, what would your next step be?
Obstructive sleep apnea (OSA) is characterized by repeated cycles of partial airway obstruction, hypoxemia, sympathetic discharge, and arousal to restore ventilation. In addition to fragmented sleep and daytime sleepiness, this common sleep disorder is associated with a decreased functional capacity1-3 and an increased risk for accidents, arrhythmias, myocardial infarction (MI), stroke, and death.4-6 In the Wisconsin Sleep Cohort, an 18-year follow-up study, the estimated hazard ratio for patients with severe OSA was 3.0 for all-cause mortality (95% CI; P-trend <.008) and 5.2 for cardiovascular death (95% CI; P=.003).7
The prevalence of OSA in the United States is 3% to 7% for males and 2% to 5% for females, with higher rates among those older than 65 years. But these figures apply only to those with an OSA diagnosis. An additional 5% of the general population is believed to have undiagnosed OSA.4,8
Arriving at an OSA diagnosis may not be difficult with a patient like Mr. M, who is obese and has classic symptoms. But it is important to consider OSA in patients who, like Ms. C, are not overweight and whose chief complaint appears to be unrelated to sleep.
This review—of risk factors, common (and uncommon) symptoms, diagnostic criteria, and treatment for OSA—highlights key indicators and optimal therapies.
The OSA profile: Risk factors and presenting symptoms
Obesity is perhaps the best-known risk factor for OSA: About 70% of patients with OSA are obese, and 40% of obese individuals have OSA. Approximately 60% of those with OSA have metabolic syndrome.9-12 But it is important to remember that individuals with normal or even low BMI may develop OSA, as well.
Other possible contributing factors include alcohol use, smoking, nasal congestion, menopause, polycystic ovary disease, and a genetic predisposition. And OSA may cause or worsen a wide range of conditions, including hypertension, congestive heart failure, atrial fibrillation, stroke, and nocturnal arrhythmias.8,13
Symptoms may be classic—or not
A bed partner’s complaint about a patient’s snoring, typically followed by arousal and gasping for air, is often the first indication of OSA. Loud snoring and daytime sleepiness are the most common symptoms. But not all patients present with these classic symptoms. Some may complain of irritability, difficulty concentrating, daily headaches, and nocturia.
Because the symptoms of OSA are not highly specific, a wide differential diagnosis must be considered, including numerous causes of excessive daytime sleepiness and conditions, such as panic attacks, pulmonary disease, and gastroesophageal reflux disease, which can interfere with sleep (TABLE 1).8,13
What to include in the medical history and work-up
When you suspect OSA or another sleep disorder, the medical history should include a complete review of systems. The social history needs to include information regarding alcohol intake, use of sedatives, and recreational drugs. If possible, interview the patient’s bed partner, as well.
Examine upper airway anatomy. In performing a physical exam, pay special attention to blood pressure, BMI, and upper airway anatomy. Assess for conditions that can cause obstruction, such as nasal congestion, septal deviation, retrognathia (malocclusion of the mouth due to an abnormal posterior position of the maxilla or mandible), macroglossia (an unusually large tongue), dental malocclusion, enlarged lymphoid tissue and tonsils, large uvula, low hanging soft palate, and a large neck circumference (>40 cm for females and >43 cm for males).13