[Long-term effects of continuous positive airway pressure treatment on subclinical atherosclerosis in obstructive sleep apnoea syndrome]. 
Obstructive sleep apnoea (OSA) is associated with an increased risk of cardiovascular disease.  Our objective was to evaluate subclinical atherosclerosis in OSA patients and the effect of continuous positive airway pressure (CPAP) treatment on carotid intima-media thickness (cIMT).  We included 125 patients with suspected OSA.  After polysomnography, 107 patients were diagnosed with OSA; 58 of these met the criteria for CPAP treatment.  cIMT was measured by ultrasonography at baseline in all patients and after 2 years of follow up in 50 patients on CPAP and 35 without CPAP treatment.  The average cIMT was significantly thicker in OSA than in non-OSA patients (665±120 vs. 581±78μm, P=.005) and did not differ according to OSA severity.  Atheromatous carotid plaque was more prevalent in OSA than non-OSA patients (48 vs. 2%, P=.004).  Among OSA patients, the mean cIMT remained stable over time in the group without CPAP, whereas cIMT decreased markedly in the CPAP group (679±122 vs. 631±117μm, P<.0001).  Increased cIMT was associated with presence of OSA, but not with its severity.  Carotid ultrasound in OSA is a reliable marker of atherosclerosis.  CPAP treatment with CPAP in OSA reduces cIMT and cardiovascular risk.