RB1 and hyperthyroidism: , while lower serum Co and Rb were found to be associated with hyperthyroidism (OR = 0.988, 95% CI: 0.976–0.999, and P = 0.036 for Co and OR = 0.910, 95% CI: 0.839–0.988, and P = 0.024 for Rb) in the adjusted model (Table 3).