ESPE Abstracts (2016) 86 P-P1-898

Do Different Initial Doses of L-T4 within the Range of 10-15 mcg/kg/day Influence Neurodevelopment during the First Two Years of Life in Children with Congenital Hypothyroidism?

Andrea Espositoa, Carmela Bravaccioa, Dario Bruzzeseb, Alessandra Cassioc, Roberto Gastaldid, Alessandro Mussae, Elena Peronif, Miriam Polizzia, Maria Cristina Vigonef, Malgorzata Gabriela Wasniewskag, Giovanna Weberf & Mariacarolina Salernoa

aDepartment of Translational Medical Sciences, University of Naples Federico II, Naples, Italy; bDepartment of Public Health, University Federico II of Naples, Naples, Italy; cPediatric Department, Sant’Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy; dDepartment of Pediatrics, Istituto Giannina Gaslini, Genoa, Italy; eDepartment of Pediatrics and Public Health, Regina Margherita Children’s Hospital, University of Turin, Turin, Italy; fDepartment of Pediatrics, Vita-Salute San Raffaele University, IRCCS San Raffaele Hospital, Milan, Italy; gDepartment of Pediatrics, University of Messina, Messina, Italy

Background: The initial L-T4 dose currently recommended in the treatment of congenital hypothyroidism (CH) is 10–15 mcg/kg per day.

Objective and hypotheses: We designed a multicenter randomized trial to evaluate the effects of different starting doses of L-T4 within the range 10–15 mcg/kg per day on neurocognitive development in children with CH.

Method: Seventy-two children with CH diagnosed by neonatal screening were enrolled in the study. They were randomly assigned to receive an initial L-T4 dose of 10–12.5 mcg/kg per day (group A) or 12.6–15 mcg/kg per day (group B). All patients underwent clinical examination and FT4 and TSH measurement periodically during the first two years of life. At the age of 12 and 24 months they underwent Griffiths Mental Development Scales to evaluate cognitive development.

Results: Growth during the first two years of life was comparable in the two groups of patients. Neurodevelopmental evaluation showed no significant differences in Global and Subscales Quotients between the two groups both at 12 and at 24 months of age.

Table 1. Neurodevelopmental and growth outcomes in CH children at 24 months
Group AGroup BP
Global Developmental Quotient112.6±22.0112.1±22.6Ns
Locomotor Subscale111.8±22.198.7±23.1Ns
Personal-social Subscale99.7±21.991.7±20.4Ns
Language Subscale91.2±20.787.7±21.7Ns
Eye-hand coordination Subscale105.6±12.7104.5±14.6Ns
Performance Subscale107.5±10.5104.8±13.0Ns
Length SDS0.18±0.940.54±0.98Ns
Weight SDS 0.11±1.280.28±1.08Ns

Conclusion: Different initial doses of L-T4 within the range of 10–15 mcg/kg per day are not associated with differences in neurodevelopment and growth during the first two years of life in CH patients.