Table 1 Natural history studies of subclinical hypothyroidism in children.
From: Subclinical Hypothyroidism in Children: Normal Variation or Sign of a Failing Thyroid Gland?
Patient population | N with SCH | Years of f/u | Outcomes | Ref |
|---|---|---|---|---|
Abnormal newborn screening TSH | 28 | 7.2–9.5 years | 9 with normal TSH 19 with TSH 4–10 0 with TSH >10 | [4] |
Children in a single health care system screened in 2002; no known thyroid disease | 3,475 | Up to 5 years | 73.6% with normal TSH ≈ 25% with TSH 5.5–10 ≈ 2% with TSH >10 | [3] |
Idiopathic SCH—no antibodies, no goiter | 92 | 2 years | 38 with normal TSH 43 with TSH 5–10 11 with TSH >10 (10.5–15) | [5] |
Autoimmune thyroiditis: nl T4 and TSH 5–64 mU/L | 18 | Mean of 5.8 years | 7 with normal TSH 10 with normal T4, ↑ TSH 1 with low T4, ↑ TSH | [6] |
Autoimmune thyroiditis | 55 | At least 5 years | 16 with normal TSH 16 with TSH 1-2x ULN 23 with TSH > 2x ULN | [7] |
Patients with SCH maintained on low doses of l-thyroxine | 30 | Mean of 3.5 years on l-thyroxine then stopped | 14 with TSH <5 12 with TSH 5–9.9 4 with TSH 10–15 | [9] |
Down syndrome: mean age 16.4 ± 10 years | 70 | 2–7 years | 19 with normal TSH 46 with SCH 3 with overt hypothyroidism 2 with hyperthyroidism | [10] |