Risk factors for Obstructive Sleep Apnoea

Obesity. Being overweight leads to an accumulation of fat in the neck and base of the tongue; this increases the likelihood of the upper airway (UAW) collapsing while asleep. In addition, the fat deposited between the muscle fibres in the throat reduces their ability to contract.

Male. Men have greater pharyngeal and laryngeal resistance and therefore a more collapsible upper airway than women.

Age. The older a person, the lower the muscle tone of the upper airway dilator muscles and, consequently, the lower the pharyngeal resistance to collapse.

Alcohol. This is a muscle relaxant (it reduces muscle tone in the genioglossus) and so increases the collapsibility of the upper airway; increasing the intensity of snoring and worsening apnoea in patients suffering from obstructive sleep apnoea. In addition, it is a central nervous system depressant that reduces the body’s response to hypoxia and, therefore, lowers the threshold for waking up during apnoea.

Tobacco. Smoking irritates the mucous membranes.

Hypnotics or central nervous system depressants, such as codeine, morphine, neuroleptics, anxiolytics and barbiturates, among others, can worsen obstructive sleep apnoea due to their sedative and muscle-relaxing effect.

Anatomical factors that favour the obstruction of the upper airway (UAW). Adeno-amygdala obstruction, craniofacial abnormalities.

Hormonal factors such as hypothyroidism.

Neurological and respiratory diseases.

Anatomical factors that can lead to upper airway obstruction, such as Adenotonsillar hypertrophy, macroglossia and craniofacial malformations (e.g. retrognathia and micrognathia).