UCLA

Congenital hypothyroidism (CH) is a condition of severe thyroid hormone (TH) deficiency present at birth. The current treatment is clear, and straightforward - a daily oral dose of thyroxine (T4). But, knowing precisely how much T4 to give and how to adjust dosages over time is an unsolved major treatment issue. Too much can produce side effects throughout life; too little is not enough to sustain normal growth and development. We developed and quantified a non-linear, multi-compartmental CH neonate model, as an adaptation of an existing simulator of feedback control of human TH levels in children and adults. Using a simulation approach, we found that simulated L-T4 plus L-T3 treatment is better than L-T4 alone treatment and the best treatment for CH babies is 1st 8 mcg/kg L-T4, followed by 0.5 mcg/kg/day L-T4, with 0.10 mcg/kg/day L-T3 over the first month of life - the period for which we had reliable data.