BACKGROUND: Study on the association of white matter lesions with obstructive sleep apnea hypopnea syndrome and its risk factors. METHODS: A recruited study with a sample of 172 patients from the department of neurology of the Third Affiliated Hospital of Southern Medical University between 2015 and 2019. RESULTS: According to the univariate analysis, the independent variables where < 0.1 were included in the multivariate logistic regression model. After adjusting for confounding factors, the two-category logistic regression showed that Obstructive sleep apnea hypopnea syndrome (OSAHS) (OR = 8.347, 95%CI: 2.561 ~ 27.212, < 0.001) were independent risk factors for WML, and that the prevalence of Cerebral white matter lesions (WML) increased with the severity of OSAHS ( = 0.002). In the non-OSAHS group, the mild OSAHS group, and the moderate-to-severe OSAHS group the apnea-hypopnea index (AHI) in the supine position was significantly higher than that in the left or right lateral position, showing a decreasing trend. The SaO2 < 90% total sleep time (TST SaO2 < 90%) showed an increasing trend, as did the body mass index. In the OSAHS severity groups, the AHI in the supine position was significantly higher than that in the left or right lateral position. Spearman correlation analysis showed that WML was positively related to AHI in the supine position (r = 0.209, = 0.006). CONCLUSIONS: OSAHS was an independent risk factor for WML. There was a positive relationship between WML and AHI in the supine position. ABBREVIATIONS: AHI, apnea-hypopnea index; OSAHS, obstructive sleep apnea hypopnea syndrome; WML, white matter lesions; MRI, magnetic resonance imaging; BMI, body mass index; TSTSaO2 <90%, SaO2 <90% total sleep time; LSaO2, lowest oxygen saturation level; CI, confidence interval; OR, odds ratio.