Sleep apnea is a sleeping disorder caused due to difficulties in breathing. It is a critical condition as it deprives the oxygen levels to the organs and leads to uneven heart rhythms. Sleep apnea, which has been known to increase the risk of cardiovascular disease, may also increase the risk of cancer.

Sleep apnea occurs when muscles relax while sleeping, thus the soft tissue in the throat starts to sag and restricts the airway. The condition is distinguished by episodes of respiratory cessation, often lasting 10 to 30 seconds, resulting in oxygen deprivation. It has been associated with an increased risk of death due to heart disease, low blood sugar, and insulin resistance (all of which contribute to diabetes), as well as anxiety disorders, stroke, and accidents caused by drowsiness.

Types of Sleep Apnea

There are three types of sleep apnea:

1. Obstructive Sleep Apnea (OSA): It occurs when the back of the throat's airway gets physically closed. This blockage causes brief interruptions in breathing.
2. Central Sleep Apnea (CSA): Is caused when the brain's system for coordinating muscles involved in respiration malfunctions, resulting in slower and shallower breathing.
3. Mixed Sleep Apnea: When a person has both obstructive sleep apneaand central sleep apnea, the condition is known as mixed sleep apnea or complex sleep apnea.

What happens when you stop breathing?

When you stop breathing, your heart rate tends to decline as your body is deprived of oxygen for an extended period of time. At the end of that period of no breathing, your involuntary reflexes shock the body and you wake up. When this happens, your heart rate quickens, and your blood pressure rises. Due to increased workload, the walls of the heart thicken changing the structure of the heart. It tends to become stiffer and less flexible.

These are the alterations that occur when you stop breathing. However, if you have regular apnea, your body begins to suffer from chronic repercussions. Data suggests an elevated risk, especially if you stop breathing 30 times or more each hour. However, even at lower frequency rates, there is likely to be a risk.

What causes sleep apnea?

Obesity, large neck size, and structural anomalies in the head and neck are all factors that predispose individuals to tissue collapse in the throat. Other risk factors are:

• Heavy alcohol consumption
• Smoking
• Family history

Symptoms

All three types of sleep apnea share common symptoms. Most of which are-

• Snoring, especially loud which may involve choking and gasping for air
• Excessive daytime sleepiness
• Fatigue
• Awakening unexpectedly with a sensation of gasping or choking
• Irritability
• Limited attention span
• Morning sore throat and dry mouth
• Nocturia

In most cases, a person suffering from sleep apnea is unaware of their breathing problems at night. Generally one comes to realize the problem when it is pointed out by your partner, member of the family, or roommate. Excessive daytime sleepiness is the most common sign of sleep apnea in those who live alone.

Sleep apnea and Cancer

Though there are suggestions, the biochemical mechanism linking sleep apnea to an elevated risk of cancer is not entirely known.

Breathing interruptions during the night may create not just fragmented sleep but also oxidative stress, which indicates that cells in all sections of the body are more stressed at the molecular level. This stress may cause increased inflammation throughout the body and may be a key pathway to cancer risk.

Sleep-related breathing difficulties are frequent in patients with head and neck tumors who have sleep disruption. The most common complaints are weariness and sleepiness during the day. The presence of malignancies in the head and neck region should raise clinical suspicion as a risk factor for sleep-related respiratory impairment, specifically OSA.

Treatments

Conservative therapy may be all that is required in mild cases of obstructive sleep apnea.

• People who are overweight can benefit from decreasing weight. For most patients, even a 10% weight loss can lower the number of apneic incidences.
• Individuals with obstructive sleep apnea should avoid alcohol and certain sleeping drugs.
• You should avoid sleeping on the back.
• Nasal sprays or breathing strips should be used to minimize snoring and increase airflow for more comfortable breathing.

Sleep apnea can sometimes easily be fixed with lifestyle modifications. If you think that you have symptoms of sleep apnea then you can consult a healthcare professional.

- By Dr. Shalini Thakur, Consultant Head and Neck Surgical Oncologist, HCG Cancer Hospital, Bengaluru