Natural history of thyroid function in adults with Down syndrome - 10-year follow-up study

Background The natural history of thyroid function in adults with Down syndrome (DS) is unknown. Method This study investigated annual thyroid function tests in 200 adults with DS over a 10‐year period. Results Transient and persistent thyroid dysfunction was common. The 5‐ and 10‐year incidence of definite hypothyroidism was 0.9%−1.64% and 13.6%, respectively. Subclinical hypothyroidism was not found to be an early sign for definite hypothyroidism. Conclusions Routine screening for adults with DS who are euthyroid can be reduced to every 5 years rather than the present policy of every 1–2 years.