Age-Specific Distribution of Serum Thyrotropin and Antithyroid Antibodies in the U.S. Population: Implications for the Prevalence of Subclinical Hypothyroidism

Context: Measurements from all age groups defined the upper limit of the TSH reference range in National Health and Nutrition Examination Survey III. The TSH median, 97.5 centile and prevalence of subclinical hypothyroidism (SCH), normal serum T4 and TSH greater than 4.5 mIU/liter, increased progressively with age. Age-adjusted reference ranges would include many people with TSH greater than 4.5...