Table 2 The Table displays mean ± standard deviation of age at diagnosis, starting dose of levo-thyroxine (LT4), height (H) at puberty onset, final height (FH), and target height (TH) in the recruited patients divided in quartiles on the basis of birthdate. ^a vs 4 th quartile p ≤ 0.001; ^b vs 4 th quartile p ≤ 0.005; ^c vs 1st quartile and vs 2nd quartile p < 0.05

Age at diagnosis (days)

28.5 ± 11.9 ^a

27.6 ± 12.6 ^b

23.4 ± 7.3

20.8 ± 7.4

Starting LT4/kg/day (μg)

7.5 ± 2.4 ^a

7.6 ± 2.3 ^a

8.9 ± 2.4 ^{a, c}

11.2 ± 3.0

H at puberty onset (SDS)

-0.2 ± 1.0

0.0 ± 1.0

0.0 ± 1.0

-0.1 ± 0.8

FH (SDS)

-0.1 ± 1.1

0.0 ± 1.1

-0.1 ± 1.0

-0.3 ± 0.9

TH (SDS)

-1.0 ± 0.9 ^a

-0.9 ± 1.2

-0.7 ± 0.8

-0.5 ± 0.9