However, simple linear regression analysis showed significant correlations of the plasma Ngal level with the following parameters of OSA: AHI (r = 0.24, p = 0.01), 4%ODI (r = 0.26, p = 0.01) and time of SpO2<90% (r = 0.23, p = 0.02). This evidence concerns the gene LCN2 and obstructive sleep apnea syndrome.