Effects of CPAP on 'vascular' risk factors in patients with obstructive sleep apnea and arterial hypertension

AY Litvin,1 ZN Sukmarova,1 EM Elfimova,1 AV Aksenova,1 PV Galitsin,1 AN Rogoza,2 IE Chazova11Department of Systemic Hypertension, 2Department of New Methods of Diagnostics, Russian Cardiology Research and Production Complex, Ministry of Health, Moscow, Russian FederationBackground: The aim of this study was to assess the effects of continuous positive airway pressure (CPAP) on arterial stiffness, central blood pressure, and reflected pulse wave characteristics in patients with severe obstructive sleep apnea (OSA) and stage 2–3 arterial hypertension.Methods: Forty-four patients with hypertension and severe OSA (apnea/hypopnea index > 30) received stepped dose titration of antihypertensive treatment, consisting of valsartan 160 mg + amlodipine 5–10 mg + hydrochlorothiazide 25 mg. CPAP therapy was added after 3 weeks of continuous antihypertensive treatment with BP < 140/90 mmHg or after adjusting triple treatment in patients with resistant arterial hypertension. The patients were randomized to effective CPAP (4–15 mm H2O) or placebo CPAP (pressure 4 mm H2O) for three weeks, then crossed over to the alternative treatment in a single-blind manner. Office blood pressure (BP), ambulatory BP monitoring, ambulatory arterial stiffness index (AASI), aortic BP, carotid-femoral pulse wave velocity (cfPWV), and systolic wave augmentation index were measured using a Sphygmocor® device at baseline, after antihypertensive treatment, placebo CPAP, and effective CPAP.Results: Baseline cfPWV was above the normal range in 94% of patients. After reaching target BP, the cfPWV decreased by 1.9 ± 1.0 msec (P = 0.007). Effective CPAP achieved a further cfPWV reduction of 0.7 msec (P = 0.03). Increased arterial stiffness (pulse wave velocity > 12 msec) persisted in 35% of patients on antihypertensive treatment and effective CPAP, in 56% of patients on antihypertensive treatment alone, and in 53% of patients on placebo CPAP