Abstract: Objective  To systematically evaluate the relationship between the carotid atherosclerotic plaque and the serum chitin enzymes protein 40 (YKL 40) level in patients with atherosclerotic cerebral infarction (ACI). Methods  Literature about the influence of serum YKL 40 levelonACIpublished before Jan.1, 2018 were searched. The search was conducted in databases including CNKI, Wanfang Dataand PubMed. The casecontrol study about the YKL40 levelbetween ACI patients(ACI group) and patients without ACI(control group) were included in this study. Quality evaluation and data extraction were carried out, and meta analysis was performed by RevMan 5.3.Results  Sevencasecontrol studies were included in this study, including  649  patients in the ACI group and 290patientsin the control group. The result showed that the serum YKL 40 level of the ACI group were much more higher than that of thecontrol group, and the differences is statistically significant (SMD=1.55,95%CI=1.391.71,P<0.01);  In the ACI group, the serum YKL 40 level among patientswith stable plaques was lower than that of patients withunstable plaques. Conclusion  The level of serum YKL40 is positively correlated with the occurrence of ACI in China, and the higher the serum YKL40 is, the worse the stability of atherosclerotic plaques is.

Key words: brain , infarction, atherosclerosis;chitin enzymes protein;meta analysis