How Sleep Apnea Affects Weight

Sleep apnea, also called obstructive sleep apnea, is a medical condition that many people live with. If left untreated, can cause many symptoms and potentially lead to complications such as weight gain, heart disease, diabetes, and metabolic syndrome.

This article will review the causes of sleep apnea, how it can cause weight gain, and how sleep apnea is treated.

What Is Sleep Apnea?

Sleep apnea is a disorder in which the airway becomes obstructed, or narrowed, while you are sleeping. The narrowing of the airway then leads to impaired breathing while sleeping.

The lack of air entering the lungs causes hypoxia (decreased oxygen level in the blood). This then disrupts the sleep cycle, and someone with sleep apnea may then wake up.

This cycle continues over and over as someone is sleeping, up to dozens of times each hour. Disrupted sleep due to apnea may produce a variety of symptoms. 

Symptoms

Symptoms of sleep apnea can include:

• Snoring
• Waking up with a headache
• Waking up with a dry mouth
• Difficulty falling asleep
• Difficulty staying asleep
• Waking up short of breath
• Feeling more irritable during the day
• Daytime drowsiness
• Sleep partner noticing periods of not breathing

Causes

When someone with sleep apnea is sleeping, their airway becomes blocked. Some causes are:

• Obesity: Someone who has obesity or is overweight may have a large neck, with increased fat in the tissue around the airway. When lying down, this tissue presses on the structures of the airway, closing them off. 
• Fluid overload: People who are living with heart or kidney disease may hold on to more fluid in their bodies. This places pressure on the airway structures during sleep.
• Anatomy: Having large tonsils may obstruct the airway when lying down to sleep. Other anatomical changes can include having been born with the tongue farther back in the mouth, cleft lip, or cleft palate. 

Nerve or Muscle Changes

Sometimes damage to nerves in the brain, neck, or chest, can interfere with how well you are able to keep your airway open at night when sleeping. Some of the conditions that can affect the nervous system or muscular system include:

• Stroke (damage to the brain due to a blocked blood vessel or bleed)
• Myasthenia gravis (an autoimmune disease affecting muscular movement)
• Chiari malformation (a condition of the brain present at birth)
• Amyotrophic lateral sclerosis (ALS) (a disease that attacks the nerves controlling muscle movement)

Weight and Sleep Apnea

Sleep apnea is a common condition in those who have obesity. It is often thought to be a reversible cause of sleep apnea, meaning that if weight can be lost, the sleep apnea can resolve. However, sleep apnea is linked to weight gain, which can make losing weight difficult.

Weight Gain

Studies have demonstrated how the shortened sleep cycles experienced with sleep apnea can cause obesity. Weight gain from sleep apnea can be a very complex process of increasing inflammation in the body, combined with glucose intolerance, insulin resistance, and hormone imbalances.

A hormone called leptin is stored in fat cells in the body. It signals the hypothalamus (in the brain) to let the brain know that the body is full and doesn’t need to eat. Sleep apnea can lead to a decrease of leptin production, so the brain doesn’t get the signal that the body is full.

People with obesity may also have higher levels of leptin due to the increased number of fat cells in the body. Sometimes the brain becomes desensitized to the action of leptin, and signals do not get across.

There are other hormones and signaling proteins found in fat cells that can affect how the brain functions during sleep. They can lead to the nerves and muscles in the chest and upper airway becoming weak and unable to keep the airway open during sleep.

This then causes inflammation to occur, which can lead to weight gain. This can be a difficult cycle to break.

Another hormone, gherlin, stimulates appetite. This hormone is released from the stomach to tell the brain it is hungry. With decreased sleep, as experienced in sleep apnea, the amount of gherlin is increased, causing the appetite to increase.

Weight Loss

Weight loss has been encouraged as an intervention for people with sleep apnea to help reduce their risks and complications from the sleep disorder. However, after reviewing the ways in which sleep apnea can cause weight gain, losing weight may be difficult.

Losing weight can be attempted through dietary changes, increased exercise, or medications. Weight loss surgery has also been used to help people with sleep apnea lose weight.

However, one of the treatments of sleep apnea, using continuous positive airway pressure (CPAP) therapy at night has been shown to improve some of the hormone imbalances associated with sleep apnea. Regular use of a CPAP may be helpful in losing weight.

Risk Factors

Many factors can contribute to sleep apnea. Some of these risks factors are:

• Increasing age
• Regular alcohol use
• Cigarette smoking
• Family history
  
• Male sex

People of African American, Hispanic, or Native American heritage also have an increased risk of sleep apnea.

Sleep Apnea Complications

Getting a diagnosis and treatment for sleep apnea can reduce the risks of the serious complications of this condition. Some of the complications that can arise include:

• Asthma: A chronic lung condition with constricted and inflamed airways
• Atrial fibrillation: Irregular, rapid, and chaotic heart rhythm
• Cancers: Including those of the pancreas, kidney, and skin
• Chronic kidney disease: Gradual loss of kidney function
• Difficulties with brain function: Affects attention, concentration, movement, and memory
• Heart and blood vessel conditions: Including atherosclerosis (narrowing of arteries due to plaque buildup), heart attacks (a blocked blood vessel causes damage to the heart muscle), heart failure (the heart can't pump blood adequately), high blood pressure, and stroke
• Eye conditions: Including glaucoma, dry eye, and keratoconus (bulging of the cornea)
• Metabolic disorders: Including glucose intolerance and type 2 diabetes (both result in high blood sugar)

Diagnosis

Sleep apnea diagnosis begins with seeing a healthcare provider if you or your sleep partner is concerned that you may have sleep apnea. The provider will perform a physical examination and will assess your sleep apnea symptoms. They may refer you to a sleep specialist, who can perform a sleep study to evaluate you.

Sleep studies can be done in a specialized sleep lab, or may be done at home. During a sleep study, heart rate and rhythm and oxygen levels are monitored during sleep. There is also an evaluation of how many times apnea episodes occur.

Sleep apnea can be graded into mild, moderate, or severe based on the number of apnea episodes that occur each hour. If you have mild sleep apnea, you will have four to 15 episodes of apnea in an hour. If you have moderate sleep apnea, you'll experience 15 to 29 apnea events per hour. And if you have 30 or more apnea episodes per hour, your sleep apnea is severe.

Treatment

Multiple interventions can be taken to help treat sleep apnea and reduce the risk of some of the health problems that can be associated with it. Treatments can include making lifestyle changes, using machines or other devices to help with breathing during sleep, and undergoing surgery, if necessary. 

Lifestyle Changes

Losing weight can be helpful in treating sleep apnea, but, at the same time, sleep apnea can make it very difficult to lose weight. Things such as limiting calories, drinking fewer alcoholic beverages, and not smoking can reduce sleep apnea symptoms.

Machines and Devices

A CPAP machine can be prescribed to someone with sleep apnea. This machine has a mask that fits over the nose and/or mouth, which is then connected with tubing to a machine that provides pressure to keep the airway open while sleeping.

Devices that are available include mouthpieces that position the jaw and stops it from moving while sleeping to help keep the airway open. There is also an oral device that keeps the tongue in a special position to prevent it from blocking the airway.

There is also an implantable device that monitors breathing patterns while someone is sleeping. If it senses a change in breathing patterns, it provides stimulation to the nerves to help keep the airway open.

Surgery

If enlarged tonsils are causing sleep apnea, having a tonsillectomy (surgically removing the tonsils, the soft tissue masses at the back of the throat) may be needed. Other procedures can include surgery to reposition either the upper or lower jaw.

Summary

Sleep apnea is a condition in which the airway has difficulty staying open while someone is sleeping, either due to anatomic or neurological reasons or possibly due to being overweight or obese.

This leads to decreased respiratory cycles while sleeping, including periods of not breathing. This decreased breathing then causes oxygen levels in the body to drop and interferes with the sleep cycle.

Sleep apnea can lead to multiple complications, including weight gain, hypertension, heart disease, and metabolic syndrome. Sleep apnea must be diagnosed by a healthcare provider through a physical exam, a review of symptoms, and a sleep study.

Treatment options for sleep apnea can include lifestyle changes, uses of devices or machines, such as a CPAP, or possibly even surgery. 

A Word From Verywell

Sleep apnea is a condition that can lead to serious problems. It is important to get your symptoms evaluated by a healthcare provider. Many people think that sleeping with a CPAP device will be uncomfortable or difficult to do, however, it can lead to better sleep and better overall health.