M. Safwan Badr, MD: What are the Novel Treatments for Central Sleep Apnea?

Central sleep apnea (CSA) and obstructive sleep apnea (OSA) may sound similar but have morphologic distinctions.¹ CSA has no generated effort—the brain not sending proper signals to the muscles that control breathing.² In contrast, OSA, the more common form of sleep apnea, has generated effort with the throat muscles relaxing and blocking the flow of air into the lungs.

OSA and CSA have overlapping symptoms of loud snoring, periods of stopping breathing during sleep, gasping for air during sleep, awakening with a dry mouth, morning headache, insomnia, hypersomnia, difficulty paying attention while awake, and irritability.

“We have to realize that these two things are intertwined,” M. Safwan Badr, MD, from Wayne State University, told HCPLive at SLEEP 2024, the 38th annual meeting of the Associated Professional Sleep Societies.¹ “The etiology is not as separate as we may think. Morphology does not equate etiology.”

The most common causes and risk factors linked with CSA development include heart failure with reduced ejection fraction, opioid use, and being at a high altitude such as 8000 feet. However, in scenarios where there is no reason why a patient developed CSA, it is called primary.

“Now, one of the things that are missed in this conversation is that even in [the] healthy population, there are differences in central apnea,” Badr said.

For instance, he said men are more likely to develop CSA than women.

“It's uncommon on a polysomnogram to see a young woman who has central apnea,” he said. “However, once a woman reaches menopause, her risk of developing central apnea increases.”

Effective traditional treatments exist for CSA, like positive airway pressure therapy, supplemental oxygen, and adaptive servo ventilation. Continuous positive airway pressure (CPAP) is a first line therapy and helps 50% to 60% of individuals with CSA. Novel treatments for CSA include phrenic nerve stimulation and pharmacological therapy.

Most of the CSA treatments are repurposed from OSA. CPAP for OSA has a 95% efficacy and for CSA it has about 50% efficacy. The treatment works slightly different for people with CSA as it serves as a driver and prevents hyperventilating and the development of another apnea. Yet, many people with CSA have comorbid OSA, which may be why CPAP is very effective for both conditions. About two-thirds of patients with CSA have OSA too.

“I would envision that many future interventions will involve CPAP plus another intervention…because if you correct the central apnea but leave the obstructive apnea untouched, we haven't helped you,” Badr said. “For the two thirds of the patients who have both, it will probably be treatment of both conditions.”

References

1. ^{Badr, M. Novel Treatments for Central Sleep Apnea. Session presented at SLEEP 2024. Houston, TX. June 5, 2024.}
2. ^{Sleep Apnea. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/sleep-apnea/symptoms-causes/syc-20377631#:~:text=Obstructive%20sleep%20apnea%20(OSA)%2C,the%20muscles%20that%20control%20breathing. Accessed June 10, 2024.}