Circadian Rhythm and Its Impact on Sleep Apnea

Did you know that the Circadian rhythm controls many of your vital human functions, not just sleep? Circadian rhythm is a 24-hour cycle that guides many of the body’s most important functions. It works in tandem with your biological clock, which regulates the circadian rhythm and takes its cues from the environment and personal changes, such as across-time zone travel or cell phone usage. 

While circadian rhythm controls the digestive, immune, and endocrine systems, it is most commonly associated with the sleep-wake cycle, which affects people with sleep apnea the most.

Sleep-Awake Cycle Linked To Daytime Health

The sleep-wake cycle is critical to assuring a good night’s sleep. Environmental cues such as the amount of sunlight help your biological clock signal when it is time to wake up and be alert. As daylight ends and night begins to fall, the sleep-wake cycle triggers the release of melatonin, a hormone that naturally aids sleep. 

When your circadian rhythms are well-aligned, deep, restful sleep is attainable. But some conditions can interrupt your circadian rhythms, resulting in daytime exhaustion from disrupted sleep. 

For the over 1 billion people who suffer from sleep apnea worldwide, an out-of-sync circadian rhythm adds to an already unhealthy sleep pattern. Sleep apnea sufferers have symptoms such as morning headaches, brain fog, and afternoon onset exhaustion. These symptoms stem from a reoccurring cycle of waking numerous times throughout the night, often with gasping and accompanied by snoring. Untreated sleep apnea is associated with more serious comorbidities, including cardiovascular disease, hypertension, and stroke.

Healthy Sleep Starts With Good Sleep Hygiene

Changes to your daily routine can throw your circadian rhythms out of alignment. If you stay up extra late and then sleep in well beyond your normal routine, your circadian rhythm can be thrown off. Part of good “sleep hygiene” is to try not to get too little or too much sleep, but to keep to a routine of consistent timing for going to bed and waking up. 

Travel that takes you across time zones throws off your circadian rhythm. We’ve all experienced this “jet lag,” and experts at Harvard Medical School suggest a few simple changes to minimize its effect and reset your circadian rhythm. Gradually following the timeline of your new destination before leaving home has been shown to minimize the effects of jet lag, as has staying well-hydrated and adapting to your new destination’s meal times and bedtime as quickly as possible. 

Another situation many people are guilty of is being on their phone or computer late into the night. The light from these devices confuses the circadian rhythm, signaling the body that it is still daylight.

Disrupted Rhythms Negatively Affect Sleep Apnea

Studies such as those done at the American Thoracic Society show that misaligned circadian rhythms can negatively affect obstructive sleep apnea. Further research reveals that disruption with circadian rhythm could increase the frequency of apnea events. These studies are corroborated by the fact that more extensive apnea events occur in the early morning hours when circadian rhythms signal that it is daytime and time to wake up.

If you have sleep apnea, practicing good sleep habits, like turning off the computer or putting down the phone well before bedtime, and keeping a routine sleep schedule, will help minimize changes to your body’s circadian rhythms. And because sleep apnea is grossly underdiagnosed, those experiencing any of the symptoms of sleep apnea should get tested for this serious sleep health disorder. 

Circadian rhythms are tied to virtually every bodily process, so keeping them aligned, much like getting a good night’s sleep, is good for overall health and well-being.