woman who fell asleep on the couchSometimes your body confuses healthy cells for invading cells, more commonly known as an autoimmune response.  If the autoimmune response isn’t treated, your immune system can attack healthy tissues. This can cause a plethora of certain medical conditions, including hypothyroidism.

The two major thyroid gland disorders include hypothyroidism and hyperthyroidism.  Hypothyroidism refers to the inadequate secretion of thyroid hormones, which is more commonly known as having an underactive thyroid.  As a result of this, there may be changes within the upper airway that lead to difficulties breathing during sleep.

Did you know that individuals diagnosed with hypothyroidism are almost twice as likely to have a diagnosis of Obstructive Sleep Apnea?  According to studies, the prevalence of hypothyroidism in the United States is about 9.47%.  While men are more likely to be at risk for OSA, women are more likely to have an underactive thyroid.  About 1 in 6 women will develop hypothyroidism by age 60.
Symptoms of hypothyroidism which coincide with OSA symptoms are as follows:

  • Difficulty concentrating
  • Weight gain
  • Fatigue
  • Depressed mood
  • Reduced desire
  • Sleep difficulties

If you have some of the above listed symptoms, it may be time to speak with your doctor about getting a blood test to evaluate the function of your thyroid if this is abnormally elevated, suggesting that the thyroid is not working properly. It is important to tell your physician if any family members have had this same diagnosis – you may be at a higher risk because of it.
Hypothyroidism can lead to increased upper airway dysfunction and collapsibility, due to soft tissue swelling in tongue, neck, and pharynx.  When severe, it can also result in blunted ventilatory drive and impaired chemosensory response to hypoxia/hypercapnia.  It has also been known to weaken the diaphragm, resulting in decreased lung volumes, which in turn contributes to more severe OSA.

If your thyroid gland is not functioning properly, then your metabolic rate will most likely be low. For that reason, an underactive thyroid is commonly associated with weight gain. The more severe the condition, the more weight you are likely to gain.

Hypothyroidism is relatively easy to diagnose and treat.  Most treatments rely on supplementing low hormone levels with artificial varieties. These hormones will replace what your body isn’t producing on its own and help return your body’s functions to normal.  Determining if you have OSA at the same time can be a little tricky, since many of the symptoms present the same.  With the right testing/evaluation, your physician can ensure that you are receiving the proper treatment for both disorders.

For those already diagnosed with hypothyroidism, who also have symptoms of sleep apnea, a PSG (overnight sleep test) can help determine whether sleep apnea is present.  Fortunately, if hypothyroidism is causing sleep apnea or other sleep disordered breathing, it will most likely improve with thyroid hormone replacement. This is typically taken as a pharmaceutical pill called Synthroid (levothyroxine).  Natural alternatives are available as well, such as Armour thyroid.

In patients with hypothyroidism, disordered breathing appears to be very common; yet in patients with OSA, hypothyroidism is very uncommon.  One potential advantage of diagnosis of hypothyroidism prior to polysomnography is that polysomnography, an expensive and time-consuming test, might be avoided if the hypothyroid patient’s subjective complaints are ameliorated by levothyroxine replacement.

Hormone problems can wreak havoc on health, especially when it comes to sleep. In addition to symptoms mentioned above, there are additional sleep-related issues such as insomnia and night sweats.  Night sweats can also be associated with the onset of menopause, but that only pertains to a specific age range of women.  There may be frequent awakenings during the night, especially during REM sleep.  Due to the poor-quality sleep, the time in bed may be extended, even though you’re not actually sleeping but just lying there trying to rest.  If the time in bed exceeds the amount of sleep that is needed to feel rested, chronic insomnia may occur.

To understand the potential link between hypothyroidism and sleep apnea, a team from Texas Tech University Health Sciences Center (TTUHSC) embarked upon new research using data mined from the National Health and Nutrition Examination Survey (NHANES). Their study, “Hypothyroidism and its Association with Sleep Apnea Among Adults in the United States: NHANES 2007-2008,” was published in July by the Journal of Clinical Endocrinology & Metabolism.  A brief summary of the study can be found online.
For additional information on OSA and/or sleep disorders, please visit our website.