INS and diabetes mellitus: For the VTDR that occurred in the long-duration group, the independent risk factors included younger age at diabetes onset (OR = 0.95; 95% CI:0.92–0.98; p <0.001), female gender (OR = 1.42; 95% CI:1.02–1.96; p = 0.037), higher systolic blood pressure (OR = 1.01; 95% CI: 1.00–1.03; p = 0.014), and higher glycated hemoglobin (OR = 1.12; 95% CI: 1.03–1.22; p = 0.007), insulin use (OR = 1.53; 95% CI:1.09–2.16; p = 0.015), and the presence of DN (OR = 1.46; 95% CI:1.03–2.06; p = 0.034) (Table S2).