Several participants had TH levels suggestive of undiagnosed primary hypothyroidism (fT4 < 0.6 ng/dL and TSH > 5.6 mIU/L, n = 3), subclinical hypothyroidism (0.6 ≤ fT4 ≤ 1.6 ng/dL, and TSH > 5.6 mIU/L, n = 21, including 2 participants in the T1I1 group), primary hyperthyroidism (fT4 > 1.6 ng/dL and TSH < 0.34 mIU/L, n = 3), or subclinical hyperthyroidism (0.6 ≤ fT4 ≤ 1.6 ng/dL, fT3 ≤ 3.9 pg/mL and TSH < 0.34 mIU/L, n = 16) using NHANES 2007–2008 clinical cutoffs (NHANES 2007a). Here, TH is linked to Primary hypothyroidism.