Sustained attention in school-age children with congenital hypothyroidism: Influence of episodes of overtreatment in the first three years of life.

INTRODUCTION

Children with congenital hypothyroidism (CH) are at risk of developing mild cognitive impairment despite normal overall intellectual performance. These deficits may be caused by disease-related and treatment-related factors. This study explores the impact of abnormal thyroid function during the first 3 years of life on attention performance at school age.

METHODS

We included 49 children diagnosed with CH and receiving treatment for the condition: 14 boys (mean age 9.5±2.8 years) and 35 girls (9.6±2.6 years). The number of episodes of normal, under-, and overtreatment were estimated based on TSH levels during their first 3 years of life (at 12, 18, 24, 30, and 36 months). Children were assessed using a computerised version of a Sustained attention test. General linear models were calculated with the attention index as the dependent variable and sex, aetiology, and number of episodes of normal, under-, and overtreatment as independent variables.

RESULTS

Higher numbers of episodes of overtreatment (low TSH level) were associated with poorer attention performance at school age (P=.005, r=-0.45).

CONCLUSIONS

Children with CH should be monitored closely during the first 3 years of life in order to prevent not only hypothyroidism but also any adverse effects of overtreatment that may affect attentional function at school age.