INS and type 1 diabetes mellitus: Table 2 shows the medication usage in all T1D. All T1D patients used different regimen of insulin, and the median total daily dosage of insulin between different age at onset groups was not significant (P = 0.14). In CANTAB tests, no significant group differences were found by nonparametric tests. However, we used the multivariable linear regression to investigate the association of different T1D onset groups and the log-transformed CANTAB tests with adjustment of the age, disease duration, and education years. The mean response latency of RVP had significant group differences (P = 0.02).