Relationship between obstructive sleep apnea and markers of cardiovascular alterations in never-treated hypertensive patients

We addressed a question if there is a relationship between severity of newly diagnosed obstructive sleep apnea (OSA) and markers of cardiovascular alterations in middle-aged untreated hypertensive patients. In 121 consecutive patients with never-treated essential hypertension (mean age 35.9 +/- 10.1 years; 97 men and 24 women) evaluation of office and ambulatory blood pressure (BP) measurements, metabolic syndrome (MS) components and markers of alterations in cardiovascular system including left ventricular structure and function, carotid artery wall intima-media thickness (cIMT) and urinary albumin excretion (UAE) was performed. OSA was classified as mild (apnea/hypopnea index (AHI) 5-15 events h(-1)) or moderate-to-severe (AHI > 15 events h(-1)). Mild and moderate-to-severe OSA were diagnosed in 30% and 20% of patients, respectively. No differences in nighttime BP levels and decline between patients with and without OSA were observed. The patients with moderate-to-severe OSA were characterized by higher cIMT (0.74 +/- 0.16 vs. 0.60 +/- 0.15 mm; P = 0.001), UAE (14.5 +/- 6.9 vs. 10.0 +/- 8.0 mg 24 h(-1); P = 0.014), relative wall thickness (0.42 +/- 0.05 vs. 0.39 +/- 0.05; P = 0.023) and by a higher degree of diastolic dysfunction (E'-wave velocity 11.4 +/- 3.2 vs. 15.5 +/- 3.8ms(-1); P<0.001) as compared with the patients without OSA. In multivariate analysis, AHI independently of BP and MS components correlated with UAE, relative wall thickness and E'-wave velocity. In the middle-aged never-treated hypertensive patients, moderate-to-severe OSA correlates with markers of cardiovascular alterations independently of BP levels and MS components.