Note: 1) Totally 9 figures were contained in figure 2, the detailed subgroups were listed as follow from left to right: 1) up row: males, females, total study population, 2) middle row: age<45 years-old, age between 45–64 years-old, age≥65 years-old, 3) down row: BMI<24.0, BMI between 24.0–27.9, BMI≥28.
2) Chi-square tests, ρ values for the non-linearity between serum selenium and diabetes ORs were listed as follow: 2A (F=6.07, ρ=0.04), 2B (F=5.62, ρ=0.04), 2C (F=5.26, ρ=0.07), 2D (F=3.54, ρ=0.10), 2E (F=4.79, ρ=0.08), 2F (F=5.89, ρ=0.05), 2G (F=11.82, ρ<0.01), 2H (F=2.11, ρ=0.18), 2I (F=0.89, ρ=0.51)