Table 2.

Risk Reduction of Thyroid Autoimmunity in the Individual Patient

Susceptibility factor	Mechanism	Reduce or monitor risk
Genetic background: family history of thyroid disease	Increases genetic susceptibility to environmental triggers	Awareness/avoidance of triggers; low clinical threshold for thyroid function testing
Dietary iodine	Increased immunogenicity of thyroglobulin, thyroid cell destruction	Maintain regular and sufficient intake, especially during pregnancy
Dietary selenium	Interaction with immune response	Avoid deficiency, benefit of supplements not established, but may reduce antibody production in specific settings
Cigarette smoking	May increase cytokines in orbit and thyroid, complex interactions with the immune system	Increased risk of Graves' disease and Graves' ophthalmopathy; reduced risk of Hashimoto's disease
Medical radiation	Increases thyroid antigens, inflammation	Awareness of increased incidence of Hashimoto's and Graves' disease, thyroid function test monitoring
Nuclear incident	Direct thyroid destruction, increased thyroid antigens	Potassium iodine ingestion at time of incident
Medications	Stimulation of immune response at multiple sites	Thyroid function tests and thyroid autoantibodies in susceptible individuals, thyroid function test monitoring
Environmental toxicants/chemicals	Promote autoimmune thyroiditis in susceptible animal models	Monitoring thyroid function tests and thyroid autoantibodies, test well water for contaminants