Effect of Continuous Positive Airway Pressure (CPAP) Versus Auto-titrating Continuous Positive Airway Pressure (APAP) on Resistant Hypertension (HTN) and Arterial Stiffness

Effect of Fixed Versus Auto-titrating Continuous Positive Airway Pressure on Blood Pressure and Arterial Stiffness in Patients With Resistant Hypertension and Obstructive Sleep Apnea

The primary objective is to evaluate the relative effectiveness of fixed CPAP in comparison to APAP in reducing arterial blood pressure in patients with resistant hypertension and obstructive sleep apnea (OSA).

The secondary objectives are: a) to evaluate the relative effectiveness of fixed CPAP versus APAP in improving arterial stiffness, sleep-disordered breathing, sleep quality, inflammatory markers and glucose regulation; b) to identify specific characteristic of persons who respond to the two CPAP modalities in order to identify which device is better for each subject.

The confirmatory hypothesis is that subjects with resistant hypertension and OSA will show a greater degree of blood pressure reduction after 6 weeks of treatment with fixed CPAP in comparison to those treated with APAP. Explanatory and exploratory hypotheses are that a greater reduction in arterial stiffness will be noted when compared with the benefit in blood pressure, that reductions in arterial stiffness will be associated with benefits to serum measurements of inflammatory markers and glucose regulation, and that control of sleep apnea and the attendant improvement in sleep quality will be better with fixed CPAP than APAP.

Inclusion Criteria:

• Resistant Hypertension
• Moderate Obstructive Sleep Apnea

Exclusion Criteria:

• Creatinine >150 μmol/l
• Systolic blood pressure > 170 mmHg
• Diastolic blood pressure > 105 mmHg
• Secondary cause of hypertension other than OSA
• Treatment within the last 3 months or current treatment for sleep-disordered breathing or some other sleep disorder
• Current treatment or recent treatment within the last 3 months for any other medical condition which has resulted or would be expected to result in a change in blood pressure medications