Related Experiment Videos
Soy formula complicates management of congenital hypothyroidism
S C Conrad1, H Chiu, B L Silverman
1Department of Pediatrics, Northwestern University Medical School, Chicago, IL, USA. sconrad@mail.cho.org
Insights
Soy formula in infants with congenital hypothyroidism (CH) is linked to prolonged increases in thyroid stimulating hormone (TSH). Close monitoring and potential dose adjustments for levothyroxine are recommended for these infants.
Area of Science:
- Pediatric Endocrinology
- Neonatal Nutrition
- Thyroid Disorders
Background:
- Congenital hypothyroidism (CH) requires lifelong thyroid hormone replacement.
- Dietary factors, such as soy formula, may influence thyroid hormone levels in infants.
Purpose of the Study:
- To investigate if soy formula feeding prolongs elevated thyroid stimulating hormone (TSH) levels in infants with CH.
- To assess the impact of soy formula on thyroid function in infants with congenital hypothyroidism.
Main Methods:
- Retrospective chart review of 78 infants diagnosed with CH within their first year of life (1990-1998).
- Data collected included diagnosis, treatment initiation, TSH levels, levothyroxine dosage, growth parameters, and dietary information.
- Comparison of outcomes between infants fed soy formula (n=8) and non-soy formula (n=70).
Main Results:
- Infants fed soy formula showed a prolonged increase in TSH compared to those on non-soy formula.
- Significant differences observed in time to TSH normalization, initial TSH on treatment, and elevated TSH percentages at 4 months and throughout the first year.
- No significant difference in levothyroxine starting dose or its change over one year between groups.
Conclusions:
- Soy formula consumption is associated with delayed TSH normalization in infants with CH.
- These infants require vigilant monitoring of free thyroxine and TSH levels.
- Levothyroxine dosage adjustments may be necessary to achieve optimal thyroid function in infants fed soy formula.
Aims:
To test the hypothesis that feeding soy formula to infants with congenital hypothyroidism (CH) leads to prolonged increase of thyroid stimulating hormone (TSH).
Methods:
The study was a review of 78 patients seen during their first year of life between 1990 and 1998. Data regarding clinical diagnosis, date of treatment initiation, TSH, levothyroxine dose, weight, length, and diet information from each visit were collected from the charts.
Results:
There were eight patients in the soy diet group and 70 in the non-soy diet group. There was no significant difference between the two groups in the starting dose of levothyroxine or the change in this dose over one year. There was a significant difference between the two groups in the following areas: time to TSH normalisation, first TSH on treatment, percentage with increased TSH at 4 months of age, percentage with increased TSH throughout the first year of life, and in the overall trend of TSH at each visit.
Conclusions:
Infants fed soy formula had prolonged increase of TSH when compared to infants fed non-soy formula. These infants need close monitoring of free thyroxine and TSH measurements, and they may need increased levothyroxine doses to achieve normal thyroid function tests.
Related Concept Videos
01:23Hypothyroidism II: Pathophysiology
01:20Synthesis and Regulation of Thyroid Hormones
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
01:25Hyperthyroidism I: Introduction
01:18Functions of Thyroid Hormones
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
01:27Goiter
01:27Hyperthyroidism II: Pathophysiology