Study on the relationship between serum iodine malnutrition and anti-thyroglobulin antibodies

Abstract Iodine deficiency results in elevated thyroglobulin (Tg) concentrations, with high iodine Tg being more immunogenic than low iodine Tg. This study aimed to investigate the relationship between serum iodine concentration and thyroglobulin autoantibody (TgAb) levels under different iodine nutritional statuses. Demographic information was collected from 1,482 participants through a questionnaire. Blood and spot urine were collected to measure thyroid-stimulating hormone (TSH), TgAb, thyroid anti-peroxidase antibody (TPOAb), total iodine (StI), serum non-protein-bound iodine (snPBI), urine iodine (UIC), creatinine (UCr). The median UIC and StI were 146.46 µg/L and 74.85 µg/L, respectively. A linear relationship was observed between StI, snPBI, and sPBI (P < 0.001). The 90% medical reference values for StI, snPBI, and sPBI were 50.74-120.66 µg/L, 21.86–52.87 µg/L, and 19.65–77.92 µg/L, respectively. The positive rate of TgAb was significantly higher in women than in men (P < 0.001). Both low and high levels of snPBI and sPBI were associated with an increased risk of elevated TgAb levels. In women, the risk of positive TgAb in the group below the reference value of snPBI (OR = 2.079, 95%CI: 1.166, 3.705) and sPBI (OR = 2.578, 95%CI: 1.419, 4.684) was higher. In men, the risk of positive TgAb in the group below the reference value of StI was higher (OR = 3.395, 95%CI: 1.286, 8.962). Iodine might influence TgAb levels by altering the iodine content of Tg, thus contributing to the development of autoimmune thyroid disorders.