What do heart attacks, strokes, diabetes and snoring all have in common? The answer is sleep apnea – a sleep disorder that commonly goes unnoticed in those affected but is estimated to occur in up to 25% of middle-aged men and 9% of middle-aged women in North America.
What is Sleep Apnea?
Sleep apnea is a surprisingly common sleep disorder that is characterized by abnormal declines or pauses in breathing during sleep. Each pause is called an ‘apnea’ or ‘hypopnea’ and can last from a few seconds to minutes in length – occurring 5 to 30 times or more per hour. Sleep apnea falls under the broader category of sleep-disordered breathing and is classified as mild, moderate or severe depending on the number of apnea/hypopnea episodes that occur per hour of sleep.
Individuals who suffer from sleep apnea are rarely aware of their difficulty breathing, even upon awakening. As a result, sufferers of the disorder are difficult to identify and studies show that 70-80% of those affected remain undiagnosed. Diagnosis requires conducting an overnight sleep test called a polysomnogram.
The most common signs of sleep apnea are snoring, restless sleep and excessive daytime sleepiness. Patients with sleep apnea often complain of being tired during the day, despite long hours of nighttime sleep. Furthermore, obesity increases the likelihood of suffering from sleep apnea – studies show that up to 40% of individuals that are obese also suffer from sleep apnea. Other common symptoms of sleep apnea include depression, mood swings, morning headaches and problems with attention, memory and concentration.
As time goes on, sleep apnea can wreak havoc on one’s health. It has been identified as a major risk factor for a number of cardiovascular conditions, including hypertension, coronary artery disease, congestive heart failure and stroke. Furthermore, sleep apnea has been linked to an increased risk of diabetes, cancer and even traffic accidents. Children who suffer from sleep apnea are at an increased risk of bedwetting, behavioral problems and ADHD.
The most common and effective treatment for sleep apnea is the use of continuous positive airway pressure (CPAP) machines. These involve a mask connected to an air pressure machine that is worn over the face while sleeping. Despite its well-documented effectiveness, the lack of patient adherence is a major drawback of this form of treatment. Studies show that 46-83% of patients do not adhere to CPAP treatment over the long-run.
Patients tend to favor drug therapy as a treatment for sleep apnea, but pharmaceuticals options are severely limited for this disorder. However, recent studies have found marijuana-based medications to hold promise as an effective alternative to CPAP machines for the treatment of sleep apnea.
How Can Marijuana Help?
A number of studies have investigated the effects of cannabis extracts on sleep apnea, revealing positive findings.
In 2002, researchers at the University of Illinois published the results of a study documenting the effects of cannabinoids (THC and oleamide) in animal models of sleep apnea. The results showed that both THC and oleamide were able to stabilize respiration in the animal models during all stages of sleep, decreasing apnea indexes during NREM and REM sleep stages by 42% and 58% respectively. These decreases were observed to be dose-dependent – meaning that higher doses of cannabinoids resulted in higher reductions in apnea episodes.
Following the positive results of this pre-clinical trial, lead author Dr. David Carley published the first human trial to investigate the effects of THC (dronabinol) on sleep apnea in 2013. The study involved administering varying doses of dronabinol (2.5, 5 and 10mg) to 17 test subjects prior to bedtime over a 3 week period. The results showed an overall reduction in apnea indexes of 32%, despite significant variance between patients.
Although a 32% reduction is marginal when compared to the effectiveness of current treatment options (such as CPAP and oral devices), the authors suggest that cannabinoid medications could still be of benefit to patients who suffer from mild to moderate cases of sleep apnea. Furthermore, the reduction was observed to be dose-dependent in both pre-clinical and human trials – meaning that higher rates of reduction may likely be achieved with higher doses of cannabinoids.
Dr. Carley has since received a $5 million grant from the National Institute of Health to investigate these results further in a Phase II clinical trial. If similar results are found, THC pills may become available to patients with sleep apnea in the near future.