The neutrophil-to-lymphocyte ratio in patients with obstructive sleep apnoea syndrome and its relationship with cardiovascular disease

Abstract Objective To investigate the association between the neutrophil-to-lymphocyte ratio (NLR) and obstructive sleep apnoea syndrome (OSAS) severity and whether the NLR predicts cardiovascular disease (CVD) in patients with OSAS. Background OSAS is known as a risk factor for CVD. An increased NLR was strongly correlated with cardiovascular outcomes in several studies. Methods We retrospectively examined the laboratory data for 289 patients with suspected OSAS evaluated using polysomnography. Results The study included 171 OSAS patients and 118 controls. The NLR was higher in OSAS group than control group. The NLR was significantly higher in patients with CVD than in those without (3.31 ± 1.1 vs. 1.93 ± 0.8, p = 0.002). There were also significant correlations between the NLR and apnoea-hypopnoea index, mean SaO2, and oxygen desaturation index. Conclusions There was a significant correlation between the NLR and OSAS severity and the NLR was independently associated with CVD in patients with OSAS.