Does transient hypothyroxinemia influence metabolic bone disease of prematurity?

ABSTRACT

OBJECTIVE: To investigate the relationship between Metabolic Bone Disease (MBD) and Transient Hypothyroxinemia of Prematurity (THOP). METHOD: One hundred twenty-four infants, born in Marmara University Hospital with a gestational age ≤34 weeks, were enrolled. Clinical features were recorded. Serum TSH, free T4, total T4, calcium, phosphorus and total Alkaline Phosphatase (ALP) levels were determined in the first and third postnatal weeks. MBD was defined as a phosphorus level <4.5 mg/dl and/or ALP >900 IU/l. THOP was defined as a serum free and/or total thyroxine level lower than -1 SD for gestational age at the 7th postnatal day. RESULT: THOP was diagnosed in nineteen (15.3%) patients. MBD was diagnosed in 52 (41.9%) at the 3rd month. Low birth weight, low gestational age and prolonged parenteral nutrition were associated with MBD. Multivariate analysis documented a significant relationship solely between MBD and gestational age. CONCLUSION: The risk of MBD does not increase significantly in babies with THOP.