Early treatment with L-thyroxine in children and adolescents with type 1 diabetes, positive thyroid antibodies, and thyroid gland enlargement.

Aim: To investigate whether early treatment with l-thyroxine may prevent deterioration of thyromegaly and progression to subclinical or clinical hypothyroidism in pediatric patients with type 1 diabetes, positive thyroid antibodies, and ultrasound abnormalities of the thyroid gland.

Methods: The development of thyroid gland volume and function in patients without L-thyroxine treatment (group A, n = 8) was assessed and compared with that in patients receiving L-thyroxine treatment (group B, n = 7) with median follow-up time of 2.0 yr (range 0.6-3.0 yr). Standard deviation score (SDS) of thyroid gland volume was calculated according to gender- and age-corresponding data.

Results: Median thyroid gland volume SDS at study entry was 4.8 (range 2.0-15.3) in group A and 5.6 (3.6-13.9) in group B. At follow-up, median thyroid volume SDS has increased by 0.8 (-3.9 to 6.0) at 1 yr and by 2.0 (-4.5 to 10.9) at 2 yr in group A but decreased significantly by -3.4 (-10.0 to 0.4) and -5.3 (-12.3 to -1.7) in group B, respectively. The change of thyroid gland volume was significantly different between the two groups (p = .043 and .032, respectively). In group A, three of eight patients without therapy developed subclinical hypothyroidism with thyroid-stimulating hormone elevation.

Conclusion: These data demonstrate that treatment with L-thyroxine in patients with diabetes, positive thyroid antibodies, and elevated gland volume leads to a significant reduction of thyromegaly. Prospective randomized clinical trials are required to prove these preliminary findings.