Serum TSH, T4, T3 and thyroid hormone-binding globulin (TBG) prealbumin (TBPA) and albumin (Alb) during acute and recovery stages of idiopathic respiratory distress syndrome (IRDS)

In 27 IRDS infants and 52 healthy babies blood was collected 1-2 times weekly until 30 days of life. During the first 2 days of life se-TSH was lower in IRDS than in healthy babies. Se-T4 and -T3 were low in IRDS and decreased to minimal levels by day 3-5. Se-T3 increased to normal levels by day 6-10, and se-T4 by day 21-30. Se-TBG was low in IRDS reaching normal levels during recovery. Se-TBPA and se-Alb levels were normal, but se-TBPA increased and exceeded significantly TBPA-levels of healthy babies by day 11-20. The T4/TBG ratio was low during recovery from IRDS.The low se-T4 and se-T3 values in IRDS are associated with a reduced TSH stimulation and a low se-TBG in the acute stage. During recovery, a decreased saturation of se-TBG and, possibly, an increased T4 to T3 coversion occur.