The Relationship Between the Onset of Levothyroxine Therapy in Congenital Hypothyroidism and Children's Language and Cognitive Development

Thyroid hormones play an important role in the formation and maturation of the central nervous system. Congenital hypothyroid very rarely shows clinical symptoms in early life so that cases of delayed treatment increase. Babies with untreated congenital hypothyroidism can develop into individuals with intellectual disabilities and be accompanied by motor deficits, such as impaired gross and fine motor function and balance coordination. This study aims to proving that there is a relationship between the onset of therapy in congenital hypothyroid patients and the child's language and cognitive development. The study was conducted using a cross sectional design. This research was conducted at the Children's Polyclinic at Ngoerah Hospital and Wangaya Hospital Denpasar from Desember 2022 until August 2023, using the consecutive sampling method. Based on the sample size formula of 2 unpaired proportions, the minimum number of samples is 96. Inclusion criteria are congenital hyothyroid patients were diagnosed based on TSH levels >10 uIU/mL, currently undergoing therapy and carrying out control to monitor the success of therapy for a minimum of 6 months with age < 3 years and obtain written consent from parents by signing an informed consent form. Exclusion criteria included incomplete data and clinicaly down syndrome. This study involved 107 subjects, with 45 subjects had been therapy under 3 months old and 62 subjects had been therapy more than 3 months old. Initial characteristics of the study showed that the mean age was 13.3 (±3.64) in therapy under 3 months old compare with 16.5 (±6.32) in therapy more than 3 months old. Bivariate analysis, we found significant relationship between levothyroxine therapy on language and cognitive function (p = 0.032, PR 1.74, CI=1.156-5.594). Multivariate analysis, therapy < 3 months had a significant relationship with language and cognitive development in hypothyroid children with an adjusted OR of 3.404 (95% CI 1.330 – 8.710, P value 0.011). There is a relationship between the onset of therapy in congenital hypothyroid patients and children's language development and cognition.