Endotyping in Sleep Apnea May Optimize CPAP Treatment

Wan-Ju Cheng, MD, PhD

Credit: Research Gate

New research highlighted the variations in Continuous Positive Airway Pressure (CPAP) treatment outcomes among different obstructive sleep apnea (OSA) endotypes. The study stated that by leveraging endotyping, clinicians can predict which patients are more likely to benefit from CPAP therapy and implement personalized interventions.¹

The sleep condition affects millions of people worldwide, leading to various health complications and reduced quality of life. CPAP therapy has been the go-to treatment for moderate-to-severe OSA, but its effectiveness can vary among individuals.²

This study focused on identifying OSA endotypes, or different underlying pathophysiological mechanisms contributing to the disorder. Wan-Ju Cheng, Department of Psychiatry, China Medical University Hospital, and a team of investigators aimed to determine whether CPAP treatment outcomes differ across endotypic subgroups and explore associations between specific endotypes and improvements in sleep architecture and treatment adherence.¹

The retrospective analysis was conducted using data from 225 patients diagnosed with moderate-to-severe OSA from a single sleep center. Polysomnography and CPAP titration study data were collected from May 2020 - January 2022.

CPAP treatment adherence was tracked for each patient and polysomnography data were estimated and dichotomized by OSA endotypes as high versus low: Arousal Threshold, Collapsibility, Loop Gain, and Upper Airway Gain.

CPAP Titration Pressure

Investigators observed that patients with high collapsibility required significantly higher CPAP pressure compared with those who had low collapsibility (∆ = 0.4 cmH2O, 95% CI = 0.3 - 1.7). The finding suggests individuals with higher collapsibility of the upper airway may need stronger CPAP support during sleep.

Sleep Architecture Improvements

Results demonstrated those with high arousal threshold, high collapsibility, high loop gain, or high upper airway gain experienced a more substantial increase in slow-wave sleep and rapid eye movement (REM) sleep proportions after CPAP treatment compared with those who exhibited low levels of these endotypes indicating that CPAP therapy may have a more pronounced positive impact on sleep quality in patients with specific endotypes.

CPAP Adherence

Data showed high loop gain and high collapsibility were independently associated with longer CPAP use hours per night (∆ = 0.6 h, 95% CI = 0.2 - 1.5; ∆ = 0.3 h, 95% CI = 0.03 - 1.5, respectively). Therefore, individuals with higher loop gain or collapsibility may find it easier to adhere to CPAP treatment, leading to potentially better overall outcomes, according to the study.

Future Investigation

“Although high upper airway responsiveness has been considered to be protective against obstructive sleep apnea severity, we observed that a high upper airway gain tended to be associated with a higher optimal titration pressure in the univariate regression model,” investigators wrote.

“We speculated that for patients with OSA with a strong upper airway response to intrathoracic negative pressure, the CPAP titration process reduces the negative pressure stimulus to muscles,” they continued. “Therefore, the optimal CPAP pressure for these patients must first replace their endogenous muscle activity and then overcome upper airway obstruction.”

The findings addressed significant clinical implications and expanded the understanding of the impact of OSA endotypes on CPAP treatment outcomes. Investigators noted that knowing how patients with different endotypes respond to CPAP therapy can help physicians predict treatment efficacy and tailor individualized treatment plans, and by optimizing CPAP settings based on collapsibility levels, clinicians can enhance treatment outcomes and patient adherence.

References:

1. Cheng, W.-J., Finnsson, E., Ágústsson, J. S., Sands, S. A., & Hang, L.-W. (2023). Continuous positive airway pressure and adherence in patients with different endotypes of obstructive sleep apnea. Journal of Sleep Research, e13999. https://doi.org/10.1111/jsr.13999
2. Kunzmann K. Reena Mehra, MD, MS: OSA Treatment Options. HCPLive. September 21, 2019. https://www.hcplive.com/view/reena-mehra-md-ms-osa-treatment-options