After adjusting for age, sex, diabetes mellitus status, and lymphocyte percentage, the concentration of IS (Q2: −119.1, 95% CI: −207.8 to −30.4, p < 0.01; Q3: −225.1, 95% CI: −340.2 to −110.1, p < 0.01; Q4: −448.2 95% CI: −622.0 to −274.5, p < 0.01) still negatively influenced the anti-S1 IgG titer in a dose-dependent manner (p for trend < 0.01). The gene discussed is PSMD1; the disease is diabetes mellitus.