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 age- sex- 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.