Types of Sleep Apnea-Obstructive Sleep Apnea-OSA

Obstructive Sleep Apnea:

OSA occurs when air is physically blocked from entering the lungs during sleeping. When we are sleeping all our body parts relaxes and rest so the muscles of the upper respiratory tract (nose, mouth, pharynx and larynx) also relaxes but if they relaxed too much they collapses the air way. People with OSA have an airway that is more narrow than normal, usually at the base of the tongue and palate. When lying flat, the palate is above the air passage. When the pharyngeal muscles (muscles of the pharynx or throat)

A person who has obesity and is overweight is more likely to have this disorder. In male prevalence of OSA is three times higher women. The reasons are related to hormonal influence. Gender differences in the prevalence of OSA may also be related to body fat distribution. Men exhibit a more central fat distribution, including the neck, thereby increasing the risk for narrowing and closure of the upper airway. Postmenopausal women are at higher risk for obstructive apnea. This disorder is more common in African-Americans and Hispanics.

Numerous studies have shown correlations between the prevalence of OSA syndrome and obesity. Men and women with large neck sizes: 17 inches or more for men and 16 inches or more for women.

Although obesity is the most common cause of OSA, it also occurs in non-obese patients. 

Causes of OSA:

• Narrowing of the hard palate
• Nasal abnormalities including septal deviation and allergic rhinitis.
• Children with large tonsils and adenoids.
• People with Down Syndrome.
• Increasing age - when you become older, there is an increased risk to get a sleep disorder.
• Having this disorder genetically.

Evidence is accumulating that genetic factors may be involved in the pathogenesis of apnea disorder. The risk factors arise from changes to upper airway structure alteration in craniofacial structures.

Enlargement of important upper airway structures (tongue, soft palate, and lateral pharyngeal walls). Drugs, such as narcotics, benzodiazepines and alcohol.

Macroglossia associated with hypothyroidism contributes to the higher frequency of sleep disordered breathing.

Sleep apnea syndrome is more common and often severe in acromegalic patients (a chronic disease marked by enlargement of the bones of the extremities, face, and jaw) presumably related to a large tongue narrowing the upper airway.

Smoking - decrease the amount of oxygen in your blood and with alcohol reduces the upper airway tone relax the palate can fall backwards and this can obstruct the airway risk factors of obstructive sleep apnea.