Abstract: Objective To investigate the predictive value of serum proprotein convertase subtilisin 9 (PCSK9) level in elderly patients with nonalcoholic fatty liver disease (NAFLD) in predicting the degree of atherosclerosis and prognosis. Methods From April 2020 to April 2021, 254 NAFLD patients who were treated in Tangshan Traditional Chinese Medicine Hospital and Tangshan Artificial Hospital were divided into three groups according to the quartiles of Gensini score: Group 1(Gensini score ≤ 24, n=84); Group 2(24<Gensini score ≤53, n=86) and Group 3(Gensini score>53, n=84). According to whether NAFLD patients had major cardiovascular and cerebrovascular events (MACCE), they were divided into the MACCE group(n=30) and non-MACCE group(n=224). The clinical data among the groups were compared. The relationship between Gensini score and PCSK9 was analyzed by Pearson correlation analysis. The risk factors of MACCE risk were analyzed by Cox risk model, and the predictive value of PCSK9 on the occurrence of MACCE in elderly patients with NAFLD was analyzed by ROC curve. Results hs-CRP, PCSK9, TG, LDL-C, and Lp(a) increased in Group 1 [5.79(4.17,7.81)mg/L, (329.17±50.26)ng/mL, (1.47±0.33)mmol/L, (2.69±0.52)mmol/L, (0.52±0.12)mg/L], Group 2[6.22(4.61,7.58)mg/L, (416.33±55.92)ng/mL, (1.65±0.36)mmol/L, (2.87±0.35)mmol/L, (0.63±0.09)mg/L], and Group 3[7.85(6.21,9.11)mg/L, (498.55±61.28)ng/mL, (1.86±0.24)mmol/L, (3.95±0.48)mmol/L, (0.70±0.11)mg/L] contrary to HDL-C [(1.46±0.25)mmol/L, (1.20±0.22)mmol/L, (1.06±0.27)mmol/L]]. There were significant differences between the three groups (P<0.05); PCSK9 was positively correlated with Gensini score (r=0.657, P=0.000). The age, Gensini score, PCSK9 and LDL-C of the MACCE group[[(72.12±5.54)years, (86.27±5.03)points, (489.71±63.05)ng/mL, (2.88±0.79)mmol/L] were significantly higher than those of the non-MACCE group[(68.63±3.35)years, (61.09±4.52)points, (356.03±51.19)ng/mL, (2.52±0.77)mmol/L, all P<0.05]. Multivariate Cox risk regression analysis showed that Gensini score and PCSK9 were independent risk factors for the risk of MACCE (P<0.05). The AUC of PCSK9 for predicting the occurrence of MACCE was 0.724, the sensitivity was 68.25%, and the specificity was 75.92%. Conclusion Serum PCSK9 is positively correlated with Gensini score in elderly patients with NAFLD, which could be used as a predictor of MACCE in patients.

Key words: Aged, Nonalcoholic fatty liver disease, Atherosclerosis, Circulating proprotein convertase subtilisin 9