L-thyroxine stabilizes autoimmune inflammatory process in euthyroid nongoitrous children with hashimoto's thyroiditis and type 1 diabetes mellitus

Objective: to investigate if l-thyroxine (t4) treatment may influence the clinical course of autoimmune thyroiditis (ait) or prevent progression to subclinical or overt hypothyroidism in euthyroid nongoitrous pediatric patients with type 1 diabetes mellitus (t1dm) and ait. methods: the study was performed in four polish pediatric diabetes centers. of 330 children with t1dm and ait followed between 2008 and 2012,101 received l-t4 and 160 underwent clinical observation for 24 months. thyroid stimulating hormone (tsh),free t4 (ft4),anti thyroid peroxidase antibody (anti-tpo),anti thyroglobulin antibody (anti-tg),glycosylated hemoglobin (hba1c) levels,and lipid profile were assessed in all patients. ultrasonographic evaluation was also performed in all children at each examination. results: patients treated with thyroid hormones had higher tsh levels (3.99; interquantile 3.5 to 4.52 vs. 2.09 miu/l; interquantile 1.55 to 3.06; p<0.0001). a fall in tsh level (0.87 miu/l 95% ci 0.43-1.30; p<0.0001) was documented after the first year of treatment. ft4 level did not differ between the groups at baseline (p=0.7434),but rose in the treatment group and fell in the control group [mean difference 0.78 95% ci -0.22-1.53 pmol/l (p=0.02) after 12 months and 0.98 95% ci 0.04-1.76 (p=0.005) after 24 months]. higher levels of anti-tpo were initially found in the treated patients (p<0.0001) and significantly decreased over the 24-month period (p<0.0001). children in the treatment group had higher anti-tg levels (p<0.0001),which showed a borderline decrease (p=0.08) in time. in the control group,anti-tg levels rose marginally (p=0.06) during the study. conclusions: the data demonstrate that treatment with l-t4 in euthyroid pediatric patients with t1dm and ait stabilizes autoimmune inflammation in the thyroid gland and is to be recommended as soon as the diagnosis is established. © journal of clinical research in pediatric endocrinology,published by galenos publishing.