CDK5 and Alzheimer disease: After adjusting for confounding factors, including age, sex, and BMI, by multiple linear regression, the increased AHI was significantly correlated with the decreased CDK5 level in the CSF from AD-OSA patients [β, −0.028; 95% CI (−0.047, −0.009); p = 0.004] (Figure 3 and Supplementary Table 2).