Serum YKL-40/chitinase 3-like protein 1 level is an independent predictor of atherosclerosis development in patients with obstructive sleep apnea syndrome.

OZET O sleep apnea syndrome (OSAS) is a common sleep-related breathing disorder, and is associated with several cardiovascular disturbances such as coronary artery disease (CAD), congestive heart failure, hypertension, cardiac arrhythmias, stroke and pulmonary hypertension.[1] YKL–40, also known as human cartilage glycoprotein-39 and chitinase-like protein 1, is a 40 kDa heparinand chitin-binding glycoprotein and a member of the “mammalian chitinase-like proteins”.[2,3] YKL–40, an inflammatory marker in relation to both acute and chronic inflammation and with an established role in extracellular remodelling remodeling and angiogenesis, is secreted from macrophages, neutrophils and vascular smooth muscle cells (VSMCs). [4] YKL–40 is closely related to both early and late phases of the atherosclerotic process. Several studies have shown that serum concentrations of YKL–40 are elevated in patients with CAD, and that there is an association between serum YKL–40 levels and the extent of CAD.[5,6] Carotid intima-media thickness (CIMT) is frequently used as a surrogate marker for subclinical or early atherosclerosis in epidemiological and interventional studies. However, there is little knowledge on the relationships between inflammatory biomarkers and CIMT in OSAS. Recently, YKL–40 has been shown to be associated with the presence and severity of OSAS.[7] To the best of our knowledge, there is no information about the relationship between serum YKL–40 level and CIMT in patients with OSAS. Therefore, the aim of the present study was to evaluate serum YKL–40 levels in patients with OSAS and to investigate the possible relationship between serum YKL–40 level and subclinical atherosclerosis, as assessed by CIMT, in OSAS patients.