目的：分析糖尿病视网膜病变(DR)患者血清中同型半胱氨酸(Hcy)、维生素 B12(VitB12)、叶酸的含量变化，并探讨其在DR发生发展中的意义。

方法：采用病例对照研究设计，选取2021-07/2022-01在深圳市人民医院眼科诊治的DR患者95例和在内分泌科就诊的糖尿病(DM)患者94例，以及在眼科诊治的单纯年龄相关性白内障患者87例作为正常对照组。采集受检者晨起空腹静脉血并分离血清。采用酶联免疫定量法检测每组患者血清中Hcy的浓度，化学发光免疫法检测 VitB12 和叶酸的浓度。采用Pearson线性相关分析法评估各组血清Hcy与各临床参数的相关性，采用多因素线性回归分析评估影响Hcy水平的主要因素。ROC曲线分析血清Hcy、VitB12及叶酸对DR的诊断价值。

结果：DR组血清中Hcy浓度为16.52±3.54μmol/L，明显高于糖尿病组(10.86±3.47μmol/L)和正常对照组(6.84±1.39μmol/L)(均P<0.05)； 正常对照组血清中VitB12的浓度为501.79±108.95pmol/L高于糖尿病组(478.57±57.85pmol/L)和DR组(455.88±181.49pmol/L)，但无差异(P=0.054)； 正常对照组血清中叶酸的浓度为10.31±2.43nmol/L高于糖尿病组(9.94±1.90nmol/L)和DR组(7.27±2.79nmol/L)，其中DR组与DM组之间有差异(P<0.05)； 在DR组中Hcy的表达水平与甘油三脂(TG)和低密度脂蛋白(LDL)均呈弱正相关(r=0.208，P=0.043； r=0.240，P=0.019)。多因素线性回归分析表明LDL是影响DR患者Hcy表达的重要因素。ROC曲线说明Hcy对DR的诊断具有重要价值。

结论：Hcy、VitB12及叶酸在DR组、DM组及正常对照组中存在差异性表达，其中Hcy可能参与了DR的发病进程，并对DR的诊断具有重要价值，且LDL是影响其表达的重要因素。

METHODS: A case-control study was designed. A total of 95 patients with DR(DR group), 94 patients with diabetes mellitus(DM group)treated in endgcrinology department and 87 patients with age-related cataract(normal control group)from the ophthalmology department of Shenzhen People's Hospital between July 2021 and January 2022 were selected. Fasting venous blood was collected and serum was separated. The concentration of Hcy in serum was detected by enzyme linked immunosorbent assay(ELISA), and chemiluminescence immunoassay was used to detect the concentration of VitB12 and folic acid. Pearson linear correlation analysis was used to evaluate the correlation between Hcy and clinical parameters. Multivariate linear regression analysis was used to evaluate the main factors which affect Hcy level. Receiver operating characteristic(ROC)curve was designed to analyze the diagnostic value of serum Hcy, VitB12 and folic acid in DR.

RESULTS: The concentration of serum Hcy in DR group was 16.52±3.54 μmol/L, which was significantly higher than that in DM group(10.86±3.47 μmol/L)and control group(6.84±1.39 μmol/L; all P<0.05); The concentration of VitB12 in the serum of the control group was 501.79±108.95 pmol/L, which was higher than that in DM group(478.57±57.85 pmol/L)and DR group(455.88±181.49 pmol/L), but the difference was not statistically significant(P=0.054); The concentration of folic acid in serum of control group was 10.31±2.43 nmol/L, which was higher than that of DM group(9.94±1.90 nmol/L)and DR group(7.27±2.79 nmol/L), and the difference between DR group and DM group was statistically significant(P<0.05); In DR group, Hcy expression was weakly positively correlated with triglyceride and low density lipoprotein(r=0.208, P=0.043; r=0.240, P=0.019). Multivariate linear regression showed that low density lipoprotein was an important factor which affect the expression of Hcy in DR patients. ROC curve shows that Hcy has important value in the diagnosis of DR.

CONCLUSIONS: Hcy, VitB12 and folic acid are differentially expressed in DR group, DM group and normal control group. Hcy may be involved in the pathogenesis of DR, and it has important value in the diagnosis of DR. In addition, low density lipoprotein is also an important factor which affects the expression of Hcy.