The impact of acetazolamide and dronabinol on the physiological endotypes responsible for obstructive sleep apnea
Luke D.J. Thomson a , Shane A. Landry a, Kathleen Maddison b c , Rosemarie Walsh d , Mark R. Bleackley d , Garun S. Hamilton e f, Simon A. Joosten e f, Jennifer Walsh b c, Bradley A. Edwards a g
- a
- Department of Physiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
- b
- Centre for Sleep Science, The University of Western Australia, Australia
- c
- West Australian Sleep Disorders Research Institute, Department of Pulmonary Physiology & Sleep Medicine, Sir Charles Gairdner Hospital, Australia
- d
- Incannex Healthcare Limited, Melbourne, VIC, Australia
- e
- Monash Lung, Sleep, Allergy, and Immunology, Monash Health, Clayton, VIC, Australia
- f
- School of Clinical Sciences, Monash University, Melbourne, VIC, Australia
- g
- School of Psychological Sciences, Monash University, Melbourne, VIC, Australia
Affiliationer
Study objectives
To investigate the effect of differing doses of the combination of acetazolamide and dronabinol (Aceta-Dro) on the obstructive sleep apnea (OSA) endotypes and their relationship to OSA severity.
Methods
We retrospectively analysed data from a double-blind, randomized, placebo-controlled trial of 3 different doses of Aceta-Dro [Low(125mg/2.5 mg), Medium(250mg/5 mg), High(500mg/10 mg)] in OSA patients. OSA endotypes (collapsibility [VPASSIVE], Loop gain [LG], Arousal threshold [ArTH], and muscle compensation [VCOMP]) were extracted from polysomnography signals using validated algorithms. Linear mixed models were employed to assess the impact of treatment condition on the endotypes. Linear regressions assessed the relationship between the changes in endotypes vs. apnea-hypopnea index (AHI) and to predict treatment response from baseline endotypes.
Results
Relative to placebo, Aceta-Dro dose-dependently reduced LG by 11 % (p = 0.18), 18.5 % (p = 0.022) and 20.5 % (p = 0.016). The reduction in LG was associated with a decrease in AHI in only the high dose condition (R2 = 0.78, p = 0.004). Aceta-Dro improved VPASSIVE in the low dose condition (+13 %, p = 0.005) only, which was strongly associated with AHI reduction (R2 = 0.71, p = 0.005). Aceta-Dro had no impact on VCOMP or ArTH. A higher baseline LG predicted treatment response in the high dose (R2 = 0.56, p = 0.03), with a similar trend observed in the low dose group. More severe collapsibility (lower VPASSIVE) predicted treatment response to both low (R2 = 0.46, p = 0.07) and medium dose (R2 = 0.50, p = 0.03) conditions.
Conclusions
Mechanistically, our findings suggest that medium and high doses of Aceta-Dro primarily reduce OSA severity by lowering loop gain, while the efficacy of the low dose was due to improved airway collapsibility.
