Related Experiment Videos

Serum thyroid hormones in preterm infants: associations with postnatal illnesses and drug usage

Fiona L R Williams1, Simon A Ogston, Hans van Toor

  • 1Community Health Sciences, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, Scotland, United Kingdom.

The Journal of Clinical Endocrinology and Metabolism
|August 18, 2005
PubMed

Insights

Transient hypothyroxinemia in preterm infants is linked to more postnatal factors than previously known. Addressing these factors and drug impacts may be more effective than hormone replacement alone.

Area of Science:

  • Neonatal Medicine
  • Endocrinology
  • Pediatric Critical Care

Background:

  • Transient hypothyroxinemia is common in preterm infants (<30 wk gestation) and linked to neurodevelopmental deficits.
  • Reductions in thyroxine (T4) and triiodothyronine (T3) with unchanged thyroid-stimulating hormone (TSH) characterize severe illness, but do not specify individual disease or drug impacts.

Purpose of the Study:

  • To investigate the contribution of postnatal factors to variations in serum iodothyronines, thyroid-binding globulin, and TSH levels in preterm infants.

Main Methods:

  • A cohort of 780 infants (23-34 wk gestation) was recruited across 11 Scottish NICUs from 1998-2001.
  • Serum levels of iodothyronines, thyroid-binding globulin, and TSH were assessed at 7, 14, and 28 days.
  • Adjustments were made for 31 potentially significant postnatal influences.

Main Results:

  • Serum levels of TSH, free T4, T3, and T4 showed significant associations with various factors.
  • Associated factors included bacteremia, endotracheal bacterial cultures, persistent ductus arteriosus, necrotizing enterocolitis, and cerebral ultrasonography changes.
  • Oxygen dependence and the use of aminophylline, caffeine, dexamethasone, diamorphine, and dopamine were also significantly associated.

Conclusions:

  • Numerous postnatal factors are associated with transient hypothyroxinemia in preterm infants, exceeding prior understanding.
  • Alternative strategies to direct hormone replacement, focusing on preventing or reducing illness severity, are suggested.
  • Evaluation of drug alternatives that do not interfere with the hypothalamic-pituitary-thyroid axis is recommended.
Abstract

Related Concept Videos

Graves' Disease I: Introduction01:28

Graves' Disease I: Introduction

Graves' disease is an autoimmune disorder that causes hyperthyroidism, or overactivity of the thyroid gland. It results from autoantibodies called thyroid-stimulating immunoglobulins (TSIs), which bind to thyroid-stimulating hormone (TSH) receptors, leading to overstimulation of hormone production and a hypermetabolic state.EtiologyAlthough considered idiopathic, Graves’ disease has well-established contributing factors. There is a strong genetic component, with increased prevalence in...
Factors Affecting Drug Response: Overview01:21

Factors Affecting Drug Response: Overview

When it comes to infants and young children, they are typically administered smaller doses of medication in comparison to adults. This is primarily because their organ functions still need to fully develop, meaning their bodies are not as efficient at metabolizing or eliminating drugs. Additionally, their blood-brain barrier is more permeable than in adults. As a result, high concentrations of drugs can easily penetrate the central nervous system (CNS), potentially leading to neurological...
Hyperthyroidism II: Pathophysiology01:27

Hyperthyroidism II: Pathophysiology

Hyperthyroidism is a hypermetabolic state caused by elevated levels of thyroid hormones, triiodothyronine (T3) and thyroxine (T4). It results from dysregulation at the thyroid, pituitary, or immune system level and affects multiple organ systems.PathophysiologyThe most common cause of hyperthyroidism is Graves’ disease, an autoimmune disorder in which antibodies, specifically thyroid-stimulating antibodies (TSAb), a subtype of TSH receptor antibodies (TRAb), bind to and activate TSH receptors...
Pharmacokinetics in Pediatric Patients: Drug Distribution01:17

Pharmacokinetics in Pediatric Patients: Drug Distribution

Drug distribution in the pediatric population exhibits unique challenges and considerations due to the physiological differences between children, particularly neonates and infants, and adults. A crucial aspect of pediatric pharmacology is understanding how these differences impact the pharmacokinetics of various drugs, necessitating age-specific dosing strategies to ensure efficacy and safety.Neonates and infants have a higher total body water content, ~75%–90% of their body weight, compared...
Pharmacokinetics in Pediatric Patients: Drug Metabolism01:24

Pharmacokinetics in Pediatric Patients: Drug Metabolism

In pediatric care, understanding the nuances of hepatic drug metabolism is crucial, as it significantly differs from that of adults. This divergence is primarily due to the developmental stage of drug-metabolizing enzymes, which affects how medications are processed in the body. In neonates, for instance, the activity of Phase I enzymes—critical for the initial breakdown of drugs—is markedly reduced, functioning at just 20–40% of the levels seen in adults. This reduction poses a challenge in...
Drug Toxicity: Risk factors01:24

Drug Toxicity: Risk factors

Adverse Drug Reactions (ADRs) are potential complications that arise during pharmacotherapy, influenced by multiple risk factors. Age plays a significant role; both neonates and the elderly are at heightened risk due to their respective immature and diminished metabolic and elimination processes. Gender also impacts ADRs, with females experiencing a 1.5 to 1.7-fold greater risk than males, which may be linked to pharmacokinetic, pharmacodynamic, and hormonal differences. Notably, neonates, the...