CDKN2B methylation is associated with carotid artery calcification in ischemic stroke patients

Background Cyclin-dependent kinase inhibitor 2A/2B ( CDKN2A/2B ) near chromosome 9p21 have been associated with both atherosclerosis and artery calcification, but the underlying mechanisms remained largely unknown. Considering that CDKN2A/2B is a frequently reported site for DNA methylation, this study aimed to evaluate whether carotid artery calcification (CarAC) is related to methylation levels of CDKN2A/2B in patients with ischemic stroke. Methods DNA methylation levels of CDKN2A/2B were measured in 322 ischemic stroke patients using peripheral blood leukocytes. Methylation levels of 36 CpG sites around promoter regions of CDKN2A/2B were examined with BiSulfite Amplicon Sequencing. CarAC was quantified with Agatston score based on results of computed tomography angiography. Generalized liner model was performed to explore the association between methylation levels and CarAC. Results Of the 322 analyzed patients, 187 (58.1%) were classified as with and 135 (41.9%) without evident CarAC. The average methylation levels of CDKN2B were higher in patents with CarAC than those without (5.7 vs 5.4, p = 0.001). After adjustment for potential confounders, methylation levels of CDKN2B were positively correlated with cube root transformed calcification scores (β = 0.591 ± 0.172, p = 0.001) in generalized liner model. A positive correlation was also detected between average methylation levels of CDKN2B and cube root transformed calcium volumes (β = 0.533 ± 0.160, p = 0.001). Conclusions DNA methylation of CDKN2B may play a potential role in artery calcification.