Snoring alone is not a good predictor of obstructive sleep apnoea
Snoring is caused by the vibration of the soft palate and throat during inspiration. It affects between 20 - 60% of
the adult population, and is a frequent cause of relationship strain.15 However, because snoring is so common
among otherwise healthy people, it is not a good predictor of OSAS. Snoring may also be associated with obesity, nasal
congestion, craniofacial abnormalities, hypothyroidism, acromegaly and soft tissue hypertrophy within the palate. Severe
snoring has been linked to hypertension, cardiovascular disease and cerebrovascular disease. However, it is not known
if snoring itself is an independent risk factor for cardiovascular disease.
Snoring can often be reduced with lifestyle interventions, such as weight reduction (if overweight), avoiding alcohol,
smoking and avoiding sleeping on the back. If lifestyle measures such as these do not result in reduced snoring, oral
appliances such as a mandibular splint or assessment for surgical tightening of the soft palate may be considered.16
Excessive daytime sleepiness can be a symptom of other disorders
Simple causes should be considered first when encountering a patient with excessive daytime sleepiness. Lifestyle factors
in the patient's history should be explored to uncover insufficient sleep, primary insomnia and secondary causes of insomnia,
such as depression or anxiety. Circadian rhythm disorders, e.g. jet lag, shift work or delayed sleep phase syndrome,
and sedating medicines should also be excluded.
Chronic conditions such as cardiac, respiratory or neuromuscular diseases can cause fatigue, hypoventilation and daytime
sleepiness. Carbon dioxide retention due to hypoventilation associated with severe obesity, central hypoventilation syndrome,
or chronic obstructive pulmonary disease can result in increased daytime sleepiness, which may or may not be accompanied
Unusual causes of excessive daytime sleepiness are considered last and are usually suggested by specific clinical features.
Endocrine disorders, e.g. hypothyroidism, adrenal insufficiency or diabetic ketoacidosis, and neurological causes of
drowsiness, e.g. subdural haematoma, encephalitis or intracranial neoplasm, may be a consideration, especially when the
presentation does not fit well with OSAS.
OSAS frequently occurs in conjunction with other sleep disorders such as periodic limb movement of sleep (including
restless leg syndrome), primary insomnia and narcolepsy.
For further information see: "managing
parasomnias in general practice"