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Although CPAP can be expected to achieve a lesser magnitude of blood pressure
reduction than antihypertensive medications, the effect of both therapies may be
additive. It may be prudent to manage patients’ expectations about CPAP therapy
for OSA by explaining that it is unlikely to produce blood pressure reduction suffi-
cient to allow discontinuation of antihypertensive therapy. Figure 13.5 shows one
proposed algorithm for the diagnostic management of patients with hypertension
and suspected OSA.
Mandibular Advancement Devices
Despite its established effectiveness and recent technological advances in the
device, many patients still have difficulty tolerating CPAP therapy and exhibit sub-
optimal compliance. CPAP intolerance can affect a large number of OSA patients
[ 70 ], and additional interventions, such as group education, generally fail to increase
compliance to a level that would prevent the development of comorbidities [ 71 ].
Long-term CPAP adherence rates vary widely across studies but have been as low
as 30% after 6 months of treatment [ 72 ]. In patients unable or unwilling to tolerate
CPAP, mandibular advancement devices (MADs) represent the best therapeutic
alternative [ 73 , 74 ].
Efficacy of MADs on OSA
MADs are indicated for the treatment of mild-to-moderate OSA (AHI of 5–29.9) in
patients intolerant of CPAP therapy or a rescue therapy in severe OSA patients who
are unable to achieve regular CPAP adherence. MADs advance the mandible for-
ward relative to the maxilla, thereby increasing the upper airway volume by widen-
ing the lateral dimensions of the velopharyngeal space [ 75 ]. Randomized controlled
trials and crossover studies have confirmed the efficacy of the MADs in reducing
snoring, the AHI, and the arousal index and in improving oxygenation compared to
control oral devices that do not advance the lower jaw, but there is high interindi-
vidual variability in the response to MAD therapy [ 76 – 79 ].
A parallel randomized controlled trial in mild-to-moderate OSA patients found
that MAD therapy was as effective as CPAP therapy when polysomnography-
controlled titration was done for both treatment modalities and superior to placebo
in mild-to-moderate OSA patients [ 80 ].
Several studies have shown that MADs are more successful in patients with milder
OSA, positional OSA, and lower BMI and in females [ 76 , 77 , 81 – 83 ]. However, other
studies have reported superior efficacy of CPAP compared to MADs in treating OSA
[ 82 ], and a recent review of all the studies comparing the effectiveness of the MADs to
CPAP confirmed that CPAP therapy has a superior therapeutic success rate than the
MADs even in mild-to-moderate OSA [ 84 ]. Given that adherence is at the crux of both
therapies, the superior efficacy of CPAP may not translate into better clinical outcomes
if CPAP patients are less compliant than those using MADs.
L.A. Tobias and F. Roux