Hyperthyroidism Clinical Applications Gail Nunlee-Bland, M.D. Division of Endocrinology

Hyperthyroidsim Clinical condition resulting from overactivity of the thyroid gland an an excess of circulating thyroid hormone

Hyperthyroidism Causes 2 categories Sustained hormone overproduction No associated overproduction

Hyperthyroidism Overproduction Graves’ disease Toxic multinodular goiter Toxic adenoma Iodine-induced Increase TSH secretion

Hyperthyroidism No Sustained Overproduction Thyrotoxicosis factitia Subacute thyroiditis chronic thyroiditis with transient thyrotoxicosis (painless thyroiditis, silent thyroiditis, post-partum thyroiditis Ectopic thyroidtissue (struma ovarii, functioning metastatic thyroid cancer)

Graves’Disease Diffuse goiter Thyrotoxicosis Infiltrative orbitopathy Infiltrative dermopathy

Graves’ Disease Autoimmune Antibodies against thyroid peroxidase, thyroglobulin and the TSH receptor Associated with other autoimmune disorders

Graves’ Disease Prevalence ~ 2.7% Incidence 1 case 1000/yr Most common cause of spontaneous hyperthyroidism in patients younger than age 40

Organ Specific Effects of Graves’ Disease Eyes –Infiltrative orbitopathy Skin –Dermopathy

Clinical Manifestations Thyrotoxicosis

Toxic Multinodular Goiter Generally seen in the elderly Multiple nodules are felt on exam - few of the nodules may be hyperfunctioning on thyroid uptake scan Signs and symptoms of hyperthyroidism are less pronounced Less increase in thyroid hormone overproduction

Toxic Adenoma Hyperfunctioning solitary nodule Occurs in a younger age group 30s or 40s Long-standing slowly growing lump in neck Manifestations of hyperthyroidism - less severe than in Graves’ disease Uptake scan may show hyperfunctioning nodule

Transient Hyperthyroidism Subacute thyroiditis –thyroid pain –Elevated sedimentation rate Silent thyroiditis –no thyroid pain Postpartum thyroiditis Factitious hyperthyroidism –ingestion of thyroid hormone Decreased iodide uptake on thyroid scan

Laboratory Investigations TSH Free T4 T3RIA Thyroid antibodies –Thyroid stimulating immunoglobulins Thyroid uptake scan

TBG Resin T4 Euthyroid

TBG Resin Hyperthyroid T4  T3RU  TSH 

Increase Uptake Scan Hyperthyroidism Iodine deficiency

Decrease Uptake Scan Subacute thyroiditis Factitious thyroiditis Antithyroid agents

Treatment Antithyroid drugs –Propylthiouracil –Methimazole Beta blockers Surgery Radioactive iodine

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