目的  探讨慢性肾脏病(chronic kidney disease,CKD)3～5期患者血清维生素K2(vitamin K2,VitK2)与腹主动脉钙化(abdominal aortic calcification,AAC)的相关性，分析影响血管钙化(vascular calcification,VC)的危险因素，为控制或延缓VC提供新的思路和诊治方法。 方法  选取2020年9月—2023年5月在天长市人民医院肾内科诊治的CKD 3～5期住院患者作为研究对象。根据腰椎侧位片是否存在AAC设置为钙化组和对照组。比较2组VitK2及其相关指标的差异，用二元Logistic回归法分析AAC的独立影响因素，探讨VitK2与AAC的相关性。 结果  共纳入178例患者。钙化组104例，男性59例，女性45例，年龄(67.58±11.90)岁；对照组74例，男性54例，女性20例，年龄(52.86±14.17)岁。钙化率58.43%。与对照组相比，钙化组估算肾小球滤过率(eGFR)(Z=1.974,P=0.041)、VitK2(Z=3.765,P=0.025)、血尿酸(t=2.373,P=0.022)降低，25羟维生素D3(Z=2.077,P=0.042)、C反应蛋白(CRP)(Z=3.214,P=0.001)升高。多因素分析显示VitK2(OR=0.425，95% CI：0.146～0.617，P=0.005)、eGFR(OR=0.854，95% CI：0.814～0.886，P=0.023)和年龄(OR=1.123，95% CI：1.075～1.176，P=0.001)为AAC的独立影响因素，回归模型方程为ln[P/(1-P)]=-2.657+0.122×年龄-0.166×eGFR-0.866×VitK2。相关性分析显示AAC与VitK2(r=-0.253，P=0.034)、eGFR(r=-0.263，P=0.005)呈负相关；与年龄(r=0.343，P=0.001)、CRP(r=0.241，P=0.001)和全段甲状旁腺激素(r=0.191,P=0.011)呈正相关。 结论 血清VitK2与AAC具有一定的相关性，血清VitK2、eGFR和年龄是AAC的独立影响因素，检测血清VitK2水平可作为评估VC的重要参考指标。

Objective  To investigate the correlation between serum vitamin K2 (VitK2) and abdominal aortic calcification (AAC) in patients with chronic kidney disease (CKD) at stage 3～5, and to analyze the risk factors for vascular calcification (VC), so as to provide new ideas for diagnosis, treatment, and control of VC.  Methods   A total of 178 CKD patients at stage 3～5 and hospitalized in the Department of Nephrology, Tianchang People’s Hospital from September 2020 to May 2023 were recruited as the study subjects. Lumbar lateral X-ray examination was used to determine AAC, by which patients were assigned into calcification group or control group. VitK2 and its related indexes were compared between the two groups. Binary logistic regression was used to analyze the independent influencing factors for AAC. The correlation between VitK2 and AAC was then discussed.  Results  There were 104 cases (59 males and 45 females) in calcification group, with an average age of 67.58±11.90 years, and there were 74 cases (54 males and 20 females) in control group, with an average age of 52.86±14.17 years. The overall calcification rate was 58.43%. Compared with control group, estimated glomerular filtration rate (eGFR) (Z=1.974, P=0.041), VitK2 (Z=3.765, P=0.025) and serum uric acid decreased (t=2.373, P=0.022), and serum 25-hydroxyvitamin D3 (Z=2.077, P=0.042) and CRP (Z=3.214, P=0.001) increased in calcification group. Multivariate regression showed that VitK2 (OR=0.425, 95% CI:0.146～0.617, P=0.005), eGFR (OR=0.854, 95% CI:0.814～0.886, P=0.023) and age (OR=1.123, 95% CI:1.075～1.176, P=0.001) were the independent influencing factors for AAC. The equation from regression model was ln[P/(1-P)]=-2.657+0.122×age-0.166×eGFR-0.866×VitK2. Correlation analysis showed that AAC was negatively correlated with VitK2 (r=-0.253, P=0.034) and eGFR (r= -0.263, P=0.005), and was positively correlated with age (r=0.343, P=0.001), CRP (r=0.241, P=0.001) and intact parathyroid hormone (r=0.191, P=0.011).   Conclusion   Serum VitK2 is correlated with AAC. Serum VitK2, eGFR and age are the independent influencing factors for AAC. Serum VitK2 level can be used as an important reference marker for prediction of VC.