Sleep apnea can lead to a number of complications, ranging from daytime sleepiness to possible increased risk of death. Sleep apnea has a strong association with several diseases, particularly those related to the heart and circulation.
Daytime sleepiness is the most noticeable, and one of the most serious, complications of sleep apnea. It interferes with mental alertness and quality of life. Daytime sleepiness can also increase the risk for accident-related injuries. Several studies have suggested that people with sleep apnea have two to three times as many car accidents, and five to seven times the risk for multiple accidents. Undertreated sleep apnea is a major risk factor for injury at factory and construction work sites
Effects of Sleep Apnea on Heart and Circulation
A number of cardiovascular diseases -- including high blood pressure, heart failure, stroke, and heart arrhythmias -- have an association with obstructive sleep apnea. This link may be because both cardiovascular illnesses and sleep apnea are associated with obesity and its consequences. However, large studies have increasingly suggested that OSA itself may lead to or worsen cardiovascular disease.
At this time, however, evidence of a clear causal relationship between obstructive sleep apnea and cardiovascular events is lacking. Likewise, whether treating obstructive sleep apnea improves cardiovascular outcomes has not been demonstrated.
High Blood Pressure. A number of studies have found a strong association between moderate-to-severe sleep apnea and high blood pressure (hypertension) even when obesity is not a factor. A weak, but still higher-than-normal, association with high blood pressure has also been observed in those who snore, wake frequently during the night, or have mild sleep apnea.
Coronary Artery Disease and Heart Attack. Sleep apnea has been associated with heart disease regardless of the presence of high blood pressure or other heart risk factors. Studies have shown that patients with moderate-to-severe obstructive sleep apnea have a higher risk for a heart attack.
Stroke. There is some association between the presence of sleep apnea and risk of death in patients who have previously had a stroke.
Heart Failure. Up to a third of patients with heart failure also have sleep apnea. Both central and obstructive sleep apnea are linked with heart failure. Obstructive sleep apnea can make heart failure worse, and patients with apnea have a higher mortality rate than those who do not.
Atrial Fibrillation. Sleep apnea is more common in people with atrial fibrillation (irregular heartbeat) than in patients with other heart conditions.
Other Adverse Effects on Health
Sleep apnea is associated with a higher incidence of many medical conditions, besides heart and circulation. The links between apneas and these conditions are unclear.
- Diabetes. Severe obstructive sleep apnea is associated with type 2 diabetes.
- Obesity. When it comes to sleep apnea and obesity, it is not always clear which condition is responsible for the other. For example, obesity is often a risk factor and possibly a cause of sleep apnea, but it is also likely that sleep apnea increases the risk for weight gain.
- Pulmonary hypertension.
- Asthma. Sleep apnea may worsen asthma symptoms and interfere with the effectiveness of asthma medications. Treating the apnea may help asthma control.
- Seizures, epilepsy, and other nerve disorders. There may be an association between seizures and obstructive sleep apnea, especially in older adults. Some studies have shown treatment of obstructive sleep apnea, when present, may help in the control of refractory seizures.
- Headaches. Sleep disorders, including apnea, may be the underlying causes of some chronic headaches. In some patients with both chronic headaches and apnea, treating the sleep disorder may cure the headache.
- High-risk pregnancies. Sleep apnea may increase the risk of pregnancy complications, including gestational diabetes and high blood pressure.
- Eye disorders, including glaucoma, floppy eyelid syndrome, optic neuropathy conjunctivitis, dry eye, and various other infections and irritations. Some of these latter symptoms may be associated with CPAP treatment.
Studies report an association between severe apnea and psychological problems. The risk for depression rises with increasing severity of sleep apnea. Sleep-related breathing disorders can also worsen nightmares and post-traumatic stress disorder.
Effects on Bed Partners
Because sleep apnea so often includes noisy snoring, the condition can adversely affect the sleep quality of a patient's bed partner. Spouses or partners may also suffer from sleeplessness and fatigue. In some cases, the snoring can disrupt relationships. Diagnosis and treatment of sleep apnea in the patient can help eliminate these problems.
Effects in Infants and Children
Failure to Thrive. Small children with undiagnosed sleep apnea may "fail to thrive," that is, they do not gain weight or grow at a normal rate and they have low levels of growth hormone. In severe cases, this may affect the heart and central nervous system.
Attention Deficits and Hyperactivity. Problems in attention and hyperactivity are common in children with sleep apnea. There is some evidence that such children may be misdiagnosed with attention-deficit hyperactivity disorder. Snoring, rather than sleepiness, is a stronger risk factor for hyperactivity in many of these children, especially boys under 8 years old. (Even children who snore and do not have sleep apnea may be at higher risk for poor concentration.)