The Value of Thyroid Status for the Control of Bronchial Asthma in Children

Background: Despite numerous studies, there was no consensus about the effect of thyroid hormones on asthma.

Purpose: To assess the relationship between the patient`s thyroid status and the level of BA control.

Method: 51 children with BA were examined, of them 15 girls aged 105.1+/-35.3 and 36 boys aged 114.2+/-14.1 months. All children underwent general clinical examination, spirometry, ACQ5 assessment, determination of thyroid-stimulating hormone (THS) levels, free thyroxine (free T4) test, and levels of antibodies to thyroperoxidase (anti-TPO) by ELISA.

Results: Elevated TSH levels occurred in 12 (23%) patients, while all of them had no clinical symptoms characteristic of hypothyroidism, and the maximum TSH rise was 8.45 mIU/L, which made it possible to treat this condition as subclinical hypothyroidism (cGT). None of the patients had an increase in the level of anti-TPO. Another 15 people had a TSH level in the range of 1.16-1.97 mIU/l, the remaining 24 had 2.01–3.74. 18 - had an excess of T4 free, but it was insignificant - a maximum of 23.1 pmol/l at the upper limit of the norm of 22 pmol/l, and was not accompanied by symptoms of thyrotoxicosis. Most often (in 33% of cases) subclinical hypothyroidism occurred in patients with complete control of BA (28, TSH 3.39±1.96), and was completely absent in patients with uncontrolled disease progression (5, TSH 1,87±0.73). In patients with partial BA control, TSH levels of 2.0 to 4.1 IU/L (18, TSH of 2.93±1.5) prevailed, which may indirectly indicate iodine deficiency. These differences do not reach the level of statistical significance (F =1.74, p=0.1858). Free T4 levels were comparable in all groups (16.57±1.93, 16.67±3.04, 15.82±4.93, respectively).

Conclusion: Patients with achieved BA control have a rather high incidence of subclinical hypothyroidism (23%).