Sleep Apnea, Symptoms, Causes, Diagnosis

Sleep Apnea Overview

Sleep apnea is a serious sleep-related breathing disorder that happens when a person’s breathing is interrupted during sleep.

Untreated sleep apnea causes breathing to stop repeatedly during sleep, causing loud snoring and daytime tiredness, even with a full night’s sleep. Sleep apnea can affect anyone, but most often older men who are overweight.

Patients with untreated sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night.

Most patients with sleep apnea have obstructive sleep apnea (OSA). This can occur there is a physical blockage in the upper airway. Another type, central sleep apnea (CSA), is due to a signaling problem in the nervous system.

When the airway closes, or the signal is held up, the person will stop breathing. This will happen temporarily but repeatedly during sleep. When they breathe again, they may snort, take a deep breath, or awaken completely with a sensation of gasping, smothering, or choking.

If it’s not treated, sleep apnea can cause a number of health problems, including hypertension (high blood pressure), stroke, cardiomyopathy (enlargement of the muscle tissue of the heart), heart failure, diabetes and heart attacks.

Untreated sleep apnea can also be responsible for job impairment, work-related accidents and motor vehicle crashes, as well as underachievement in school in children and adolescents.

When sleep apnea is not treated it can lead to complications such as heart disease and depression. It can also leave a person feeling drowsy, increasing the risk of accidents while driving or working.

Types of Sleep Apnea

There are two types of sleep apnea, obstructive and central:

• Obstructive sleep apnea: Obstructive sleep apnea occurs as repetitive episodes of complete or partial upper airway blockage during sleep. is the more common of the two. During an apneic episode, the diaphragm and chest muscles work harder as the pressure increases to open the airway. Breathing usually resumes with a loud gasp or body jerk. These episodes can interfere with sound sleep, reduce the flow of oxygen to vital organs, and cause heart rhythm irregularities.

 

• Central sleep apnea: In central sleep apnea the airway is not blocked but the brain fails to signal the muscles to breathe due to instability in the respiratory control center. Central apnea is related to the function of the central nervous system.Most often central sleep apnea happens in patients with neuromuscular disease such as amyotrophic lateral sclerosis (ALS, or Lou Gehrig’s disease), those who’ve had a stroke, or in patients with heart failure or other forms of heart, lung or kidney disease.
• Complex sleep apnea syndrome: This condition, which doctors also call treatment-emergent central sleep apnea, happens when you have both obstructive sleep apnea and central sleep apnea.

Prevalence of Sleep Apnea

Sleep apnea occurs in about 25% of men and nearly 10% of women. Sleep apnea can affect patients of all ages, including babies and children and particularly people over the age of 50 and those who are overweight.

Certain physical traits and clinical features are common in patients with obstructive sleep apnea. These include excessive weight, large neck and structural abnormalities reducing the diameter of the upper airway, such as nasal obstruction, a low-hanging soft palate, enlarged tonsils or a small jaw with an overbite.

What happens when someone stops breathing during sleep?

When you stop breathing, your heart rate also tends to drop the longer your body is deprived of oxygen. Then, your involuntary reflexes cause you to startle awake at the end of that period of not breathing. When this occurs, your heart rate tends to accelerate quickly and your blood pressure rises.

These are changes that take place acutely when you stop breathing. However, your body starts to experience chronic effects if you experience frequent apnea. Data suggests increased risk, particularly when you stop breathing roughly 30 times or more per hour. But there is likely a risk at even lower frequency rates.

For example, your blood pressure tends to go up, your heart walls thicken due to increased workload and the structure of your heart changes. It tends to become stiffer and less flexible because there are more fibrous cells growing in between the muscle cells.

All of those things increase the risk that you can have either atrial or ventricular arrhythmias. They also tend to reduce the function of the heart so that it’s less efficient at pumping blood.

Signs and Symptoms of Sleep Apnea

A patient with sleep apnea may be unaware of their symptoms, but another person or a family member may notice that during sleep the patient:

• Loud snoring
• Gasps for air during sleep
• Stops breathing for a while, followed by a noisy breath 
• Waking up suddenly after gasping or choking

The sleep apnea patient may notice that they experience:

• Anxiety
• Awakening with a dry mouth or sore throat
• Constant need to urinate at night
• Decreased libido
• Drowsiness
• Difficulty concentrating
• Erectile dysfunction
• Headaches, usually in the morning
• Heartburn
• Insomnia
• Irritability 
• Night sweats
• Restless sleep
• Trouble concentrating, forgetfulness, or crankiness
• Waking up several times a night to urinate

Causes of Sleep Apnea

Obstructive sleep apnea is caused by a blockage of the airway, usually when the soft tissue in the rear of the throat collapses during sleep. Several reasons can cause the blocking or collapse of the airway.

These may include the following:

• An underlying neurological problem
• Lax muscles and other tissues in the mouth and throat
• Nasal congestion
• Thickened tissues and additional fat stores around the airway

These can result from:

• Allergies
• Colds
• Genetic factors
• heart or kidney failure
• large or swollen tonsils
• Obesity
• Thyroid problems

The following are some conditions associated with Obstructive sleep apnea (OSA):

• Chronic lung disease, such as asthma, Chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis.
• Endocrine conditions, such as hypothyroidism, acromegaly, and polycystic syndrome, which may affect the breathing during sleep.
• Heart and kidney failure, which may cause fluid to build up in your neck and obstruct the upper airway
• Neuromuscular conditions, such as a stroke, which can interfere with brain signals to your chest muscles and airway. 
• Obesity hypoventilation syndrome, a breathing disorder in patients with obesity.
• Pregnancy

 

Side Effects of Sleep Apnea

If left untreated, sleep apnea can result in a number of health problems including hypertension, stroke, arrhythmias, cardiomyopathy (enlargement of the muscle tissue of the heart), heart failure, diabetes, obesity and heart attacks.

It’s likely that sleep apnea can cause arrhythmias and heart failure because if you have sleep apnea, you tend to have higher blood pressure. In fact, sleep apnea occurs in about 50% of people with heart failure or atrial fibrillation.

This is because sleep apnea can cause:

• Changes in carbon dioxide levels.
• Direct effects on the heart due to pressure changes within the chest.
• Increased levels of markers of inflammation.
• Repeated episodes of oxygen lowering (what doctors call hypoxia).

 

Risk Factors of Sleep Apnea

Sleep apnea can affect anyone, but some of the following factors can increase the risk of developing the condition:

• A large neck circumference that could make your airways more narrow
• Being male
• Down syndrome
• A narrowed airway that you inherited or developed from large tonsils or adenoids
• Being overweight
• Family history of sleep apnea
• Large tonsils
• Medical conditions such as type-2 diabetes, chronic lung diseases like asthma, congestive heart failure, hormonal disorders, high blood pressure (hypertension), Parkison’s Disease, PCOS or  prior stroke
• Menopause
• Nasal congestion
• Older age Sinusitis
• Recessed chin or large overbite 
• Smoking
• Use of alcohol, sedatives, or tranquilizers

In the United States, Black people, Hispanic people, and Native Americans are more likely to develop sleep apnea compared to white people.

Diagnosis of Sleep Apnea

A diagnosis of sleep apnea begins with a complete history and physical examination of the patients. A history of daytime sleepiness and snoring are important clues.

Your doctor will examine your head and neck to identify any physical factors that are associated with sleep apnea. They may ask you to fill out a questionnaire about daytime drowsiness, sleep habits, and quality of sleep.

If your doctor determines that you have symptoms suggestive of sleep apnea, you may be asked to have a sleep evaluation with a sleep specialist or may order an overnight sleep study to objectively evaluate for sleep apnea.

Sleep Studies

Your doctor may refer you to a sleep specialist or a hospital for a sleep study. You can do these studies in a special facility or at home. The tests will:

• Test for blood oxygen levels while you sleep
• Find low or high levels of activity in muscles that control your breathing
• Identify any events during sleep that are related to sleep apnea (when your breathing stops or slows down as you sleep) 
• Watch your heart and brain activity during rest

Based on the number of sleep apnea events you had in an hour of the sleep test, your doctor can diagnose you with mild, moderate, or severe sleep apnea.

Patients with mild sleep apnea have 5-14 apnea events in an hour, those with a moderate case have 15-29 in an hour, and doctors diagnose people with 30 or more apnea events in an hour with severe sleep apnea.

Polysomnography (PSG)

During a polysomnography, you sleep overnight in a hospital or sleep center while connected to a variety of monitoring devices that record physiologic variables.

Patterns of physiologic abnormalities during sleep may indicate sleep-disordered breathing as well as many other sleep disorders.

While you sleep, the PSG will measure the activity of different organ systems associated with sleep. It may include:

• ECG – Electrocardiogram measures heart rate and rhythm
• EEG – Electroencephalogram measures brain waves
• EOM – Electrooculogram measures eye movement
• EMG – Electromyography measures muscle activity
• POT – Pulse oximetry test measures changes in your oxygen levels in the blood

EEG and EOM

During an EEG, electrodes are attached to your scalp that will monitor brain waves before, during, and after sleep. The EOM records eye movement.

A small electrode is placed 1 centimeter above the outer upper corner of your right eye, and another is placed 1 centimeter below the outer lower corner of your left eye. When your eyes move away from the center, this movement is recorded.

Brain waves and eye movements tell doctors about the timing of the different phases of sleep. The two broad phases of sleep are non-REM (non-rapid eye movement) and REM (rapid eye movement).

Decreased muscle tone and paralysis occur during REM sleep.

EMG

During an EMG, two electrodes are placed on your chin: one above your jawline and the other below it. Other electrodes are placed on each shin.

The EMG electrodes pick up the electrical activity generated during muscle movements. Muscle relaxation should occur during sleep. The EMG picks up when your muscles relax and move while you’re sleeping.

ECG

A single lead ECG records the electrical signals from your heart during the sleep study to monitor your heart rate and rhythm.

Pulse Oximetry

In this test, a device called a pulse oximeter is clipped onto a thin area of your body that has good blood flow, such as a fingertip or earlobe.

The pulse oximeter uses a tiny emitter with red and infrared LEDs to measure the oxygen saturation level of your blood. This level may decrease during episodes of apnea.

Treatment of Sleep Apnea

Treatment aims to normalize breathing during sleep and address any underlying health problems. The options will depend on the cause and severity of symptoms.

For milder cases of sleep apnea, your doctor may recommend only lifestyle changes, such as losing weight or quitting smoking. If you have nasal allergies, your doctor will recommend treatment for your allergies.

If these measures don’t improve your signs and symptoms or if your apnea is moderate to severe, a number of other treatments are available.

Certain devices can help open up a blocked airway. In other cases, surgery might be necessary.

Therapies

• Adaptive servo-ventilation (ASV): This more recently approved airflow device learns your normal breathing pattern and stores the information in a built-in computer. After you fall asleep, the machine uses pressure to normalize your breathing pattern and prevent pauses in your breathing.

 

• Continuous Positive Airway Pressure (CPAP): If you have moderate to severe sleep apnea, you might benefit from using a machine that delivers air pressure through a mask while you sleep. With CPAP the air pressure is somewhat greater than that of the surrounding air and is just enough to keep the upper airway passages open, preventing apnea and snoring.

 

• Other Airway Pressure Devices: If using a CPAP machine continues to be a problem for you, you might be able to use a different type of airway pressure device that automatically adjusts the pressure while you’re sleeping.

 

• Oral Appliances: Another option is wearing an oral appliance designed to keep your throat open. Oral appliances might be easier to use. Some are designed to open your throat by bringing your jaw forward, which can sometimes relieve snoring and mild obstructive sleep apnea.

 

• Supplemental Oxygen: Using supplemental oxygen while you sleep might help if you have central sleep apnea. Various forms of oxygen are available with devices to deliver oxygen to your lungs.

 

• Treatment for associated medical problems: Possible causes of central sleep apnea include heart or neuromuscular disorders, and treating those conditions might help.

 

Surgery

Surgical procedure to treat sleep apnea is usually only an option after other treatments have failed. Generally, at least a three-month trial of other treatment options is suggested before considering surgery. However, for a small number of people with certain jaw structure problems, it’s a good first option.

Various surgical procedures can widen the airway in people with sleep apnea. Surgery can stiffen or shrink obstructing tissue, or remove excess tissue or enlarged tonsils.

Depending on the extent of the surgery, the person may undergo the procedure in a doctor’s office or a hospital. In general, you may consider surgical therapy when CPAP or BPAP machines or an oral appliance are not effective.

Surgical treatment may be the most effective for people who have OSA due to a severe, surgically correctable, obstructing lesion of the upper airway.

The evaluation before the surgical procedure begins with a physical exam to check on the anatomy of the patients upper airway.

Surgical options may include the following procedures:

• Creating a new air passageway (tracheostomy): Sleep apnea patients may need this form of surgery if other treatments have failed and you have severe, life-threatening sleep apnea. In this procedure, your surgeon makes an opening in your neck and inserts a metal or plastic tube through which you breathe. 

 

• Implants: Soft rods, usually made of polyester or plastic, are surgically implanted into the soft palate after you’ve received local anesthetic. More research is needed to determine how well implants work. 

 

• Jaw repositioning: In this procedure, your jaw is moved forward from the remainder of your face bones. This enlarges the space behind the tongue and soft palate, making obstruction less likely. This procedure is known as maxillomandibular advancement. 

 

• Nerve stimulation: This requires surgery to insert a stimulator for the nerve that controls tongue movement (hypoglossal nerve). The increased stimulation helps keep the tongue in a position that keeps the airway open. More research is needed.

 

• Removal of the tissue: During this surgical procedure, the doctor will remove tissue from the rear of your mouth and top of your throat. Your tonsils and adenoids usually are removed as well. This type of surgery might be successful in stopping throat structures from vibrating and causing snoring.

 

• Tissue Shrinkage: Another option is to shrink the tissue at the rear of the mouth and the back of the throat using radiofrequency ablation. This procedure might be used for mild to moderate sleep apnea patients.

 

 

Bay Biosciences is a global leader in providing researchers with high quality, clinical grade, fully characterized human tissue samples, bio-specimens, and human bio-fluid collections.

Samples available include cancer (tumor) tissue, cancer serum, cancer plasma, cancer, peripheral blood mononuclear cells (PBMC). and human tissue samples from most other therapeutic areas and diseases.

Bay Biosciences maintains and manages its own biorepository, the human tissue bank (biobank) consisting of thousands of diseased samples (specimens) and from normal healthy donors available in all formats and types.

Our biobank procures and stores fully consented, deidentified and institutional review boards (IRB) approved human tissue samples and matched controls.

All our human tissue collections, human specimens and human bio-fluids are provided with detailed, samples associated patient’s clinical data.

This critical patient’s clinical data includes information relating to their past and current disease, treatment history, lifestyle choices, biomarkers, and genetic information.

Patient’s data is extremely valuable for researchers and is used to help identify new effective treatments (drug discovery & development) in oncology, and other therapeutic areas and diseases.

Bay Biosciences banks wide variety of human tissue samples and biological samples, including cryogenically preserved at – 80°C.

Including fresh frozen tissue samples, tumor tissue samples, formalin-fixed paraffin-embedded (FFPE), tissue slides, with matching human bio-fluids, whole blood and blood-derived products such as serum, plasma and PBMC.

Bay Biosciences is a global leader in collecting and providing human tissue samples according to the specified requirements and customized, tailor-made collection protocols.

Please contact us anytime to discuss your special research projects and customized human tissue sample requirements.

Bay Biosciences provides human tissue samples (human specimens) from diseased and normal healthy donors which includes:

• Peripheral whole-blood
• Amniotic fluid
• Bronchoalveolar lavage fluid (BAL)
• Sputum
• Pleural effusion
• Cerebrospinal fluid (CSF)
• Serum (sera)
• Plasma
• Peripheral blood mononuclear cells (PBMC)
• Saliva
• Buffy coat
• Urine
• Stool samples
• Aqueous humor
• Vitreous humor
• Kidney stones (renal calculi)
• Other bodily fluids from most diseases including cancer.

We can also procure most human bio-specimens, special collections and requests for human samples that are difficult to find. All our human tissue samples are procured through IRB-approved clinical protocols and procedures.

In addition to the standard processing protocols, Bay Biosciences can also provide human plasma, serum, and PBMC bio-fluid samples using custom processing protocols; you buy donor-specific collections in higher volumes and specified sample aliquots from us.

Bay Biosciences also provides human samples from normal healthy donors; volunteers, for controls and clinical research, contact us Now.

日本のお客様は、ベイバイオサイエンスジャパンBay Biosciences Japanまたはhttp://baybiosciences-jp.com/contact/までご連絡ください。