Clinical Characteristics of People With Long-term Type 1 Diabetes

This is a single-center, prospective, observational study. The investigators propose to enroll 400 patients with type 1 diabetes (T1D) ≥10 years. The patients will be followed up annually for 3 years. In order to ensure high quality data, two staff are responsible for the input of original data into the database to check and confirm the accuracy. When the data entered by two people is inconsistent, the auxiliary staff decides which data to use. Missing data will be filled in with the multiple imputation method. The regression analysis will be used to explore the risk and protective factors for the development and progression of microvascular complications.