Our study has the following important findings: (1) the prevalence of thyroid dysfunction in an older age population was nearly 25% when accounting for treated and untreated thyroid dysfunction categories, (2) significant sex and racial differences were observed in subclinical hypothyroidism, subclinical hyperthyroidism, and treated hypothyroidism in this age group, (3) significantly lower TSH, FT4 and T3 levels were observed in older males and older black individuals, and 4) thyroid hormone levels were associated with clinical risk factors including smoking history, and BMI category. This evidence concerns the gene TG and hypothyroidism.