[A study on the mediation effect of insulin use on diabetic retinopathy in a community population].

To explore the risk factors for diabetic retinopathy (DR) in patients with diabetes and the mediating effect of insulin use on the relationship between glycated hemoglobin (HbA1c) and DR. Cross-sectional study. Random cluster sampling was conducted using a random number table method. A total of 84 sampling points (including 2 pilot points) were selected from the registered population of patients with type 2 diabetes aged 50 years and above at the Disease Prevention and Control Center in Funing County, Jiangsu Province. Questionnaires and biochemical tests were performed to obtain information on the general characteristics of the participants, medical history, insulin use, and glycated hemoglobin (HbA1c) levels. Ocular examinations, including anterior segment and fundus examinations, were conducted. The participants were divided into two groups, DR (diabetic retinopathy) and non-DR, based on the presence or absence of retinal hemorrhages, hard exudates, cotton wool spots, neovascularization, preretinal or vitreous hemorrhage. Univariate and multivariate logistic regression analyses were performed to identify the influencing factors for DR. The Karlson-Holm-Breen analysis method was used for mediation effect analysis. A total of 2 067 diabetic patients were enrolled, of whom 1 965 completed the survey and 1 802 were included in the statistical analysis, resulting in a response rate of 87.2%. Among them, 660 patients were diagnosed with DR, with a detection rate of 36.63%. The results of multivariate analysis showed that diabetes duration (=1.166, 95%: 1.138-1.196), family history of diabetes (=1.325, 95%: 1.001-1.755), insulin therapy (=1.995, 95%: 1.434-2.777), HbA1c level (=1.513, 95%: 1.189-1.925), and alcohol consumption (=0.712, 95%: 0.514-0.985) were independent risk factors for DR. The mediating effect of insulin use accounted for 13.67% of the total effect of HbA1c on DR (<0.001). The risk factors for DR in patients with diabetes include a history of insulin therapy, longer duration of diabetes, family history of diabetes, alcohol consumption, and high HbA1c levels. Insulin use increases the impact of HbA1c on DR and has a partial mediating effect on DR.