Abstract:

Objective To analyze the association between the rs562556 polymorphism of the proprotein convertase subtilisin/kexin type 9（PCSK9） gene and the degree of coronary artery stenosis in the patients with acute myocardial infarction（AMI）. Methods A total of 200 patients diagnosed with AMI from January 2021 to December 2022 were selected as AMI group， and 200 healthy individuals during the same period were selected as control group. According to the Gensini scoring standard， the patients in AMI group were divided into low risk group （Gensini score≤40， n=78） and medium-high risk group（Gensini score>40， n=122）. The levels of lipid metabolism indicators in serum of the patients in two groups were detected by fully automatic biochemical analyzer； enzyme linked immunosorbent assay （ELISA） method was used to detect the PCSK9 levels in serum of the patients in two groups； ultraviolet spectrophotometry was used to detect the single nucleotide polymorphism （SNP） of PCSK9 gene of the patients in two groups； Spearman correlation analysis was used to detect the correlation between the rs562556 polymorphism of the PCSK9 gene and the degree of the disease and the levels of lipid metabolism indicators in serum of the patients. Results Compared with control group， the percentage of smokers of the patients in AMI group was significantly increased（P<0.01）. Compared with control group， the levels of low-density lipoprotein cholesterol （LDL-c） and PCSK9 in serum of the patients in AMI group were significantly increased（P<0.05）. Compared with low risk group， the levels of LDL-c and PCSK9 in serum of the patients in medium-high risk group were significantly increased（P<0.05）. The distribution of PCSK9 gene rs1800487 genotype in both control and AMI groups conformed to the Hardy-Weinberg（H-W） equilibrium（χ²=0.677， P=0.713； χ²=0.970， P=0.831）. Compared with control group， the distribution frequencies of PCSK9 gene rs562556 genotype AA and allele A of the patients in AMI group were significantly increased（P<0.05）. In the AMI patients， the distribution of PCSK9 gene rs562556 genotype in both low risk and medium-high risk groups conformed to the H-W equilibrium（χ²=0.045， P=0.978； χ²=1.290， P=0.525）. Compared with low risk group， the distribution frequencies of genotype AA and allele A of PCSK9 gene rs562556 of the patients in medium-high risk group were significantly increased（P<0.05）. The PCSK9 gene rs562556 genotype AA was positively correlated with the degree of AMI（r=0.193， P=0.006） and LDL-c level（r=0.301， P<0.01）. Allele A was positively correlated with the LDL-c level（r=0.168， P=0.017）. Conclusion The PCSK9 gene rs562556 genotype AA is positively correlated with the degree of coronary artery stenosis of the AMI patients， and its polymorphism may promote the development of AMI by upregulating the LDL-c level.

Key words: Acute myocardial infarction, Gene polymorphism, Lipid metabolism, Proprotein convertase subtilisin/kexin type 9, Low-density lipoprotein cholesterol