关键词: 糖尿病视网膜病变, 受体, 趋化因子, 卵泡抑素相关蛋白质类

Abstract: Objective To explore the correlation between serum chemokine-like receptor 1 (CMKLR1), follistatin-like protein-1 (FSTL1) levels and the severity of diabetic retinopathy (DR). 
Methods A total of 206 patients with type 2 diabetes (T2DM) who were admitted to our hospital were selected as the research subjects. According to the severity of DR, they were divided into diabetes without DR group (n=67), background stage DR group (n=82) and the proliferative stage DR group (n=57). Another 50 healthy volunteers who underwent physical examination in our hospital during the same period were selected as the control group. The clinical data and serum CMKLR1 and FSTL1 levels of the four groups were compared. Logistic multivariate regression analysis was used to analyze the factors affecting the occurrence of DR. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of serum CMKLR1 and FSTL1 for DR. 
Results The course of diabetes in the background stage DR group and the proliferative stage DR group was longer than that of the diabetes without DR group (P＜0.05), and longer in the proliferative stage DR group than in the background stage DR group (P＜0.05). The levels of fasting blood glucose (FPG), 2 h postprandial blood glucose (2 hFPG), glycosylated hemoglobin (HbA1c), CMKLR1 and FSTL1 levels were compared among research subjects in the four groups, and the differences were statistically significant (P＜0.05). The levels of FPG, 2 hPG, HbA1c, CMKLR1 and FSTL1 in the diabetes without DR group, background stage DR group and proliferative stage DR group were higher than those in the control group (P＜0.05). The levels of FPG, HbA1c, CMKLR1 and FSTL1 in the background stage DR group and the proliferative stage DR group were higher than those in the diabetes without DR group (P＜0.05), and higher in the proliferative stage DR group than in the background stage DR group (P＜0.05). The duration of diabetes, the proportion of combined DR, the proportion of combined macrovascular disease, urine microalbumin, HbA1c, C-reactive protein, tumor necrosis factor-α (TNF-α), CMKLR1 and FSTL1 in the DR group were higher than those in the non-DR group (P＜0.05). Logistic regression analysis showed that the course of diabetes, combined DR, serum CMKLR1 and FSTL1 levels were all risk factors for DR in diabetic patients (OR=3.330, 2.746, 2.762, 2.724, P＜0.05).ROC analysis showed that the optimal cut-off points of serum CMKLR1 and FSTL1 for diagnosing DR in diabetic patients were 49.39 μg/L and 11.64 μg/L respectively. The specificity and area under the ROC curve (AUC) of the combination of serum CMKLR1 and FSTL1 were 97.01% and 0.903 respectively, which were higher than those of the serum CMKLR1 and FSTL1 levels evaluated alone. 
Conclusion There is a certain correlation between the serum CMKLR1 and FSTL1 levels and the severity of DR, and the serum CMKLR1 and FSTL1 levels have high diagnostic efficiency for the occurrence of DR in diabetic patients, and can be used as important reference indicators for clinical evaluation of the occurrence of DR. 

Key words: diabetic retinopathy, receptors, chemokine, follistatin-related proteins