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

OBJECTIVE
The inflammatory process plays an important role in the development of cardiovascular complications in patients with obstructive sleep apnea syndrome (OSAS). YKL-40/chitinase 3–like protein 1 is a novel biomarker of systemic inflammation. This study aimed to investigate whether carotid intima-media thickness (CIMT), a useful marker for early atherosclerosis, is associated with serum YKL–40/chitinase 3–like protein 1 levels in patients with normotensive and nondiabetic OSAS.

METHODS
The study included 40 OSAS patients and 40 agesex- and body mass index-matched healthy controls. Serum YKL–40 levels were detected by enzyme-linked immunosorbent assay. CIMT was measured by B-mode ultrasound.

RESULTS
The patients with OSAS had significantly increased CIMT and higher YKL–40 and high sensitivity C-reactive protein (hsCRP) levels than those of the controls. CIMT was strongly correlated with serum YKL–40 levels (r=0.694, p<0.001), hsCRP (r=0.622, p<0.001), age (r=0.525, p=0.001), and weakly correlated with apnea-hypopnea index (AHI) (r=0.365, p=0.021) and the percentage of recording time spent (PRTS) of oxygen saturation <90% (r=0.488, p=0.001). Moreover, it was detected that serum YKL-40 levels were strongly correlated with AHI (r=0.617, p<0.001), and weakly correlated with SaO2 <90% of PRTS (r=0.394, p=0.012) and hsCRP (r=0.486, p=0.001). In multiple regression analyses, age and serum levels of YKL–40 and hsCRP were found to be independent predictors of CIMT.

CONCLUSION
In patients with OSAS, CIMT was increased. This increase was associated with serum YKL–40 level. Increased serum level of YKL–40 may be an early predictor of atherosclerosis development in patients with OSAS.