Diagnosis of Carnitine Deficiency in Extremely Preterm Neonates Related to Parenteral Nutrition: Two Step Newborn Screening Approach.

Mamatha Ramaswamy,Ghassan Abdoh,Rola Fayez Mitri,Victor Anthony Skrinska

doi:10.3390/ijns5030029

Mamatha Ramaswamy, Ghassan Abdoh + Show 2 more

Open Access

https://doi.org/10.3390/ijns5030029

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Abstract

Currently, there is no evidence in the literature to support the routine supplementation of all parenterally fed premature infants with l-carnitine. In our study, we found that about 8.56% of extremely preterm neonates are diagnosed with carnitine deficiency secondary to malnutrition, either due to reduced stores at birth or related to total parenteral nutrition (TPN). Our two step approach of performing newborn screening (NBS) again at 32 weeks gestational age (GA) equivalent helps to diagnose 81.4% more preterm babies with carnitine deficiency—who would otherwise be missed—and supplement them with l-carnitine for optimal growth. We performed a retrospective cohort study to diagnose carnitine deficiency related to malnutrition in two groups: those presenting at birth and those presenting later in life. We found that there was a statistically significant difference in the median GA and birth weight (BW) between the two groups, but there was no difference in the free carnitine levels.

Highlights

Carnitine is an amino acid that plays an important role in the transport of long chain fatty acids into mitochondria where β oxidation occurs [1]
The second cohort included infants whose carnitine levels were normal on initial dried blood spots (DBS) but diagnosed later with carnitine deficiency on S32 gestational age (GA) equivalent DBS, which was related to total parenteral nutrition (TPN)
The second cohort included four infants diagnosed with carnitine deficiency at GA weeks, and initial DBS was received in these infants at around weeks GA

Summary

Introduction

Carnitine is an amino acid that plays an important role in the transport of long chain fatty acids into mitochondria where β oxidation occurs [1]. It can fulfil a detoxifying role by forming and exporting acylcarnitine esters of acyl-CoA molecules that accumulate within the mitochondria. Plasma and tissue concentrations of carnitine are low in newborn infants compared with those found in older children [2]. This may be due to the immaturity of synthetic pathways [3] or reflect a lower renal threshold [4]. The l-carnitine reserves in a full term newborn are approximately 25–50% of those in adults [2], and the reserves in preterm neonates are even lower [7]

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