Research supports use of CPAP alternative

People with hypertension and obstructive sleep apnoea were no less likely to see their blood pressure drop over six months if they used a mandibular advancement device (MAD) compared to a continuous positive airway pressure (CPAP) device, according to newly published research.
 
Presented at the American College of Cardiology’s Annual Scientific Session, the study randomly assigned a MAD or CPAP device to 220 people with moderate-to-severe obstructive sleep apnoea, before tracking a range of outcomes, including adherence, as well as ambulatory and systolic blood pressure.
 
Participants were instructed to use their device for six months while sleeping to the degree that they could tolerate it, and both devices had built-in trackers that recorded use.
 
At six months, people assigned to the MAD group experienced a drop in 24-hour ambulatory mean blood pressure that was 1.64 mmHg larger, on average, than those assigned to CPAP, meeting the threshold for non-inferiority and the trial’s primary endpoint.
 
Compared with the CPAP group, the MAD group also showed a larger between-group reduction in all ambulatory blood pressure measures, especially nighttime blood pressure when the devices were being used, and an increased proportion of patients achieving a systolic blood pressure below 120 mmHg by the end of the study.
 
None of the participants experienced symptomatic hypotension.
 
While previous studies have shown CPAP devices outperform MADs in terms of apnoea-hypopnea index, study co-author Professor Ronald Lee Chi-Hang said higher adherence among the MAD group could partly explain his team’s findings.
 
‘Looking at the totality of evidence available in the literature, it is still reasonable to say that CPAP is the first-line treatment until we have more data on the MAD,’ he said.
 
‘However, for patients who truly cannot tolerate or accept using a CPAP, we should be more open minded in looking for an alternative therapy such as a MAD, which based on our study, numerically had a better blood pressure reduction in patients compared with a CPAP.’
 
The adherence data revealed that more than half (56.5%) of those assigned the MAD used the device for six or more hours per night on average over the study period, while under one-quarter (23.2%) of those assigned to CPAP did so.
 
‘The MAD patients simply used the device longer,’ Professor Chi-Hang said. ‘That also might explain why the blood pressure reduction at nighttime, when the patients are actually using it, had a better reduction in the MAD arm.’
 
Adherence to the American Academy of Sleep Medicine’s recommendation of four or more hours of use in at least 70% of nights overall was similar between groups, with 69.4% of those in the MAD group and 64.3% of those in the CPAP group meeting this recommendation.
 
Both groups saw a reduction in daytime sleepiness and the results showed no between-group differences in cardiovascular biomarkers.
 
Overall, researchers said the results underscore the importance of treating sleep apnoea as part of a broader effort to control hypertension and reduce cardiovascular risk.
 
‘People should be aware that over 400 million people globally have moderate-to-severe obstructive sleep apnoea, and it is underdiagnosed and may be a contributing factor to their high blood pressure,’ Professor Chi-Hang said.
 
‘Especially for patients whose blood pressure is hard to control or who have a lot of excessive daytime sleepiness, [it is important to] go see a physician about sleep apnoea and get treated if necessary.’
 
Further studies in more diverse populations are necessary to determine whether the findings are generalisable to other racial and ethnic groups, the researchers said, as the study was conducted in Singapore and most participants were of East Asian descent.
 
Professor Chi-Hang added that the study taking place during the COVID-19 pandemic when lockdowns were in effect may have influenced results by increasing adherence.
 
The researchers plan to conduct further studies focused on comparing the impacts of the different types of devices on cognition.
 
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CPAP devices hypertension mandibular advancement devices obstructive sleep apnoea