Thyroid diseases in elderly.

Thyroid diseases are the commonest endocrine disorders in the general population. In most of the cases, they are consistent with benign conditions which may be asymptomatic or affect people at a variable extent. Since they often represent chronic conditions their prevalence increases by age and reaches in elderly the highest rates. Thyroid nodules are a common clinical finding. Most subjects with thyroid nodules have few or no symptoms. Thyroid nodules are more commonly non-functioning. However, in elderly, toxic multinodular goiter is the most frequent cause of spontaneous hyperthyroidism and often, it emerges insidiously from nontoxic multinodular goiter. Although autoimmune thyroiditis is the most common cause of hypothyroidism in elderly subjects, other causes, such as drugs, neck radiotherapy, thyroidectomy or radioiodine therapy, are frequently observed among these subjects. A small subset of medications including dopamine agonists, glucocorticoids and somatostatin analogs affect thyroid function through suppression of TSH. Other medications that may affect TSH levels are metformin, antiepileptic medications, lithium carbonate and iodine-containing medications. Other drugs can alter T4 absorption, T4 and T3 transport in serum and metabolism of T4 and T3, such as proton-pump inhibitors and antacids, estrogens, mitotane and fluorouracil, phenobarbital and rifampin. Amiodarone administration is associated with thyrotoxicosis or hypothyroidism. Thyroid cancer has similar characteristics in elderly as in general population, however the rate of aggressive forms such as the anaplastic histotype, is higher in older than younger subjects. Diagnosis of thyroid diseases includes a comprehensive medical history and physical examination and appropriate laboratory tests. A correct diagnosis of thyroid diseases in the elderly is crucial for proper treatment, which consists in the removal of medications that may alter thyroid function, in the use of levo-thyroxine in case of hypothyroidism, anti-thyroid drugs in case of hyperthyroidism and use of surgery, radioiodine therapy and percutaneous ablative procedures in selected cases. In conclusion, thyroid diseases in patients older than 60 years deserve attention from different points of view: the prevalence is different from the young adult; symptoms are more nuanced and makes difficult the diagnosis; age and comorbidity often force therapeutic choices and may limit safety and efficacy of therapy. Finally, in elderly patients for whom specific therapy is necessary, more gradual and careful therapeutic approach and close follow-up are recommended in order to minimize the alterations of thyroid function which are induced by many drugs commonly used in clinical practice.