What is Obstructive Sleep Apnoea (OSA)?

Obstructive sleep apnea is a potentially serious sleep disorder which causes breathing to repeatedly stop and start during sleep. It is the most common form of sleep related breathing disorders.

OSA happens when something partly or completely blocks your upper airway during sleep, causing your diaphragm and chest muscles to work harder to pull air into your lungs. You may stop breathing for 10 seconds to a minute and this lowers the blood oxygen saturation which is then followed by a brief arousal (upto 3 seconds), causing disrupted sleep. Many patients do not know they have such sleep disturbances yet these episodes can occur over a hundred times each night.

What are causes/ risk factors for OSA?

Anyone can get OSA, but certain factors contribute to higher risk including:

  1. Excess weight. About 50% of people with OSA are overweight/ obese. Fat deposits around the upper airway may obstruct breathing
  2. Chronic nasal congestion: due to narrowed airway.
  3. High blood pressure (hypertension)
  4. Diabetes: in a study done in Kenya, OSA was found to be almost twice as common in people with diabetes as those without.
  5. Smoking
  6. Sex: In most populations, men are twice as likely as women to have OSA.
  7. Asthma: Recent research has found an association between asthma and the risk of OSA.
  8. A family history: If you have family members with OSA, you may be at increased risk.
  9. Narrowed airway: This could be inherited or through enlarged tonsils/ adenoids (particularly in children), which can block your airway.
  10. Older age: this causes the upper airway muscles to get weaker and increases risk of OSA

What are symptoms and signs of OSA?

More often, it is the bed partner who notices a problem rather than the patient. There may be excessive snoring, tossing and turning and episodes of slow or stopped breathing at night. You might wake up frequently, sometimes with a sense of choking or gasping, although this is uncommon. Since you do not get a continuous sleep, you wake up feeling unrefreshed and this translates to poor concentration throughout the day. This may be accompanied by daytime sleepiness, which may cause you to fall asleep while you're working, watching television or even driving a vehicle. You could also have excessive grumpiness, mood disturbances and decreased libido.

How is OSA diagnosed?

The most crucial aspect of diagnosis of OSA is a good history from the patient. Be sure to talk to your doctor if you experience any of the stated symptoms. Loud snoring, especially snoring that is punctuated by periods of silence, is loudest when you sleep on your back, and quiets when you turn on your side is suggestive of OSA.

There are several sleep questionnaires you can be requested to fill by the doctor including: Epworth sleepiness scale, Berlin Questionnaire and STOP- BANG questionnaire which score you as having high or low risk for OSA.

Confirmatory tests include overnight sleep studies (polysomnogram) which can detect the exact episodes of pauses/ breaks and blood oxygen levels during sleep. There are new devices currently available which can enable assessment of overnight sleep at the comfort of your home.

How is OSA related to diabetes?

Diabetes is a risk factor for OSA, even without the presence of other risk factors. Interestingly, OSA can predispose to development of Diabetes. Up to 83% of individuals with type 2 diabetes suffer from unrecognized OSA and increasing severity of OSA is associated with worsening sugar control. When you have diabetes, particularly type 2 diabetes, you need to be assessed for OSA and vice versa. There are common risk factors for both diabetes and OSA including; obesity and physical inactivity.

What are the effects of OSA?

Other than predisposing to diabetes, OSA has been related to several hazards including:

  1. Daytime sleepiness and poor performance: due to disrupted sleep at night and excessive daytime sleepiness, you can get poor concentration at work and thus poor performance. Likewise, Children and young people with OSA may do poorly in school and can have attention or behaviour problems. Worse still, some individuals experience excessive sleepiness during driving/ flying and this can cause major accidents/ deaths.
  2. Cardiovascular disease: disrupted sleep and low oxygen saturation during sleep cause a strain on the cardiovascular system and can lead to conditions like high blood pressure (hypertension), angina, heart attack, stroke and heart failure. You can get heart rhythm problems which could further increase the risk of sudden death.
  3. Eye problems: recent studies have found that there OSA can increase your eye pressures (glaucoma) which is treatable
  4. Medicines and surgery: OSA can be worsened with certain medicines like narcotic pain killers, sedatives and medicines used during surgery. Therefore, if you have OSA or symptoms suggesting OSA, ensure you inform your doctor before any surgery.
  5. Social relationships: bed partners of those with OSA are often disrupted by the persistent loud snoring of patients and end up either getting disturbed sleep or moving out of the room to get a restful sleep. This may impact on relationships negatively.
  6. Others: people with OSA may also have frequent headaches, mood swings, memory problems, feeling of depression and frequent urination at night.

How can OSA be treated?

Treatment of OSA depends on the severity. For mild cases, you may be recommended lifestyle measures including: weight loss, regular physical activity, quit smoking, use of nasal decongestant sprays, avoid lying on the back, quit or reduce alcohol use.

If these measures do not work or if OSA worsens, other measures may be recommended. For severe OSA, options include:

Positive airway pressure: certain devices are attached to a mask which is fitted on the nose/ mouth to provide pressure to your airway which is higher than the air pressure around you to enable opening of your airways during sleep. Different types of positive airway pressure devices include: fixed Continuous Positive Airway Pressure (CPAP), Bilevel Positive Airway Pressure (BiPAP) or automated CPAP. You need to put on the mask at night to enable a restful sleep.

Mouthpiece/ oral device: this is a device which can be used in mild or moderate OSA. They work by either bringing your jaw forward or holding your tongue in a different position to enable good flow of oxygen at night.

Surgery: if other options fail or if OSA is due to large tonsils or adenoids, surgery is an option. Sometimes, doctors remove a part of the back of your throat (uvula) to improve snoring, though this doesn’t treat OSA. Other surgical options include: nose surgery to remove growths, jaw surgery, surgical opening in the neck (tracheostomy- in severe cases), inserting implants in the soft palate to open it further and inserting devices to stimulate the airways.