Correlation of Cognitive Performance and Thyroid Hormone Levels in Adolescents with Subclinical Hypothyroidism

Subclinical hypothyroidism (SCH) can negatively affect cognitive functioning. This study aimed at correlating serum T3, T4, TSH with adolescent’s performance on a learning disability scale. Methods: A cross-sectional study was conducted on 100 schoolchildren, (10 15 years). Thyroid hormones were estimated and classified into two groups: euthyroid and subclinical hypothyroid. NIMHANS index for Specific Learning Disabilities was used to assess the learning ability and cognitive functions. Results: Subclinical hypothyroid group made more mistakes than euthyroid group. In SCH male group, T3 correlated with language and T4 levels correlated in all areas except in language. In the females, there is no significant correlation between T3 and ability parameters except in partial correlation coeffeicient among euthyroid children in arithmetic, visual-motor skills and memory. T4 results did not correlate in language skills. There was a statistical significance between T4 and ability skills in girls except in language. TSH and language skills correlated in females. Conclusion: T3 and T4 levels have correlation with cognitive skills other than TSH. It is necessary to measure both T3 and T4 in addition to TSH in adolescents.