Obstructive sleep apnea or OSA is a type of sleep apnea characterised by multiple episodes of a partial or complete collapse of the upper airway with a gradual decrease in blood oxygen levels. Thus, it causes the person to arouse from sleep to open up the airway and allow the body to breathe.
“Obstructive sleep apnea is often associated with obesity and metabolic syndrome. Metabolic syndrome is a syndrome where a patient has high blood pressure, high blood sugar and high cholesterol levels. People with OSA usually have insulin resistance and inadequate glycaemic control and therefore develop diabetes. The upper airway occlusion (blockage) in sleep, hypoxia (low oxygen level) and arousal from sleep lead to peripheral vasoconstriction (narrowing of blood vessels) and increases blood pressure,” says Dr K Vinod, consultant pulmonologist, Veturi Polyclinic and Diagnostic Centre, Bengaluru. He also says that OSA could lead to anxiety, fatigue, poor concentration, restlessness and depression.
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Sleep apnea vs obstructive sleep apnea?
The terms sleep apnea and obstructive sleep apnea are often used interchangeably. However, they are not the same. The Journal of the American College of Cardiology defines apnea as the absence of inspiratory airflow for at least ten seconds. Sleep apnea is an umbrella term under which there are three subcategories:
- Obstructive sleep apnea
- Central sleep apnea
- Complex sleep apnea
The subcategories of sleep apnea are categorised by how the airway is blocked. In obstructive sleep apnea, the obstruction occurs in the throat and mouth. “Sleep apnea is when we stop breathing (or apnea) multiple times per hour while asleep. It can sometimes occur if the brain doesn’t send proper signals to the lungs to breathe (central sleep apnea). Still, most of the time, some obstruction in the upper respiratory tract (nose and throat passageway) can give rise to frequent apneaic spells, called OSA or obstructive sleep apnea,” says Dr Shantanu Tandon, senior ENT surgeon, airway and sleep apnea specialist, Sakra World Hospital, Bengaluru.
What is the leading cause of OSA?
So, what causes OSA? An article published in the US National Library of Medicine points out some causes of OSA:
- A lower jaw that is shorter compared to the upper jaw
- Specific shapes of the roof of the mouth (palate) or airway, causing it to collapse more easily
- Large neck or collar size, 17 inches (43 centimetres) or more in men and 16 inches (41 centimetres) or more in women
- Large tongue, which may fall back and block the airway
- Large tonsils and adenoids that can block the airway
Other causes pointed out by Dr Tandon and Dr Vinod are:
- Nasal obstruction due to deviated nasal septum and/or allergies
- Obesity and conditions that can cause weight gain like hypothyroidism, PCOD, etc
What are the symptoms?
The symptoms of OSA usually include the following:
- Poor quality of sleep with daytime tiredness
- Early secondary complications, eg: young adults with early onset hypertension
- Snoring during sleep
- Abrupt awakenings associated with gasping or choking during sleep
“Individuals who snore with sleep apnea are at high risk for developing many medical problems such as early hypertension, heart attacks, strokes and diabetes. As this often develops in young adults, long periods of OSA can have dangerous effects, including strokes,” says Dr Tandon.
Experts say that people with a history of snoring shouldn’t ignore the signs, and it’s always safe to consult a doctor to avoid irreversible damage to an individual’s mental and physical well-being.
Is OSA a disability?
Living with OSA can be highly strenuous as it impacts all aspects of life. “OSA is a definite disability. Physically it can decrease the quality of sleep and make it difficult for a person to function or concentrate. It is frequently associated with early hypertension and this may lead to many heart diseases and diabetes. All these together affect our abilities to do various physical activities well,” says Dr Tandon.
How is it treated?
Obstructive sleep apnea can be treated in many ways. “An important part of treating sleep apnea is diagnosing it and understanding its severity. The second part is identifying the location of the obstruction. Based on these facts, one may use CPAP, a device that forces air through a mask at high pressure, keeping the airway open. If an individual has a deviated nasal septum (DNS), then there can be a long-term solution through surgical correction. Likewise, tightening of loose tissues in the throat and removal of enlarged tonsils are some of the ways to treat this issue,” says Dr Tandon.
CPAP, or continuous positive airway pressure, has proven to be revolutionary in treating OSA. The Sleep Health Foundation says that CPAP therapy is an effective treatment for OSA. Research has come a long way in developing a small, compact and quiet CPAP machine compared to big ones. The design of the CPAP machine has been significantly streamlined to allow for better compliance regarding its use among individuals.
“One of the most important symptoms of obstructive sleep apnea is when people get up in the morning, they don’t feel restored because they didn’t have that restorative sleep, which is otherwise also known as REM sleep. Therefore, the metabolic rate starts coming down and then individuals start gaining weight,” says Dr Ravichandra MRK, consultant, pulmonology, Narayana Health City, Bengaluru.
He further says, “when people start becoming obese, more fatty tissues get deposited in the neck. This causes sleep apnea to become more severe and prolonged. There is even more disruption in their sleep and they start becoming inactive during the day. This becomes a vicious cycle”
An article published in the Journal of Applied Physiology highlights the relationship between obesity and OSA. According to research, obesity is one of the most critical risk factors for developing OSA. Approximately 70 per cent of OSA patients are obese. Thus, weight reduction is a step toward treating OSA.
Positive airway pressure (PAP)
PAP therapy is the first-line treatment for OSA, focusing on the most critical pathophysiological feature – impaired upper airway architecture. In this method, the person is provided with a stream of compressed air while sleeping. This treatment is recommended depending on the severity of OSA, the clinical and pathophysiological phenotypes, the existence of cardiometabolic comorbidities and other factors.
Sleeping positions for OSA
Dr Tandon recommends that individuals sleep on their side. “Although there are variable sleep positions, individuals with OSA are advised to sleep on their side as this prevents the loose muscle and tissues from collapsing into the respiratory passage,” he says.
Is there a cure?
“OSA can be cured, but the first step to a cure is finding the cause and treating it. The rest of the treatment includes taking care of the associated risk factors by lifestyle modifications like loss of weight and regular exercise,” adds Dr Tandon.
A few courses of treatment suggested by Dr Vinod are:
- Lifestyle modifications
- Physical activity
- Diet modification – eating healthy food and cutting down on excess carbohydrates
- Avoiding smoking and drinking
- Use of CPAP device during sleep