Perinatal free carnitine and short chain acylcarnitine blood concentrations in 12,000 full-term breastfed newborns in relation to their birth weight (original) (raw)
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On Carnitine Content of the Human Breast Milk
Pediatric Research, 1982
The concentration of total carnitine in human breast milk remained at a constant mean level near 62.9 range: 56.0-69.8/ nmoles/ml during the first 21 days postpartum. The carnitine level fell significantly to 35.2 + 1.26 nmoles/ml until the 40-50th day.
Carnitine concentrations in term and preterm newborns at birth and during the first days of life
PubMed, 2005
Carnitine plays an important role in energetic metabolism. The aim of the study was to characterize the carnitine status in term and preterm newborns with respect to gestational age, birth weight, haematocrit and red blood cell count (RBC). The effect of nutrition on carnitine levels in the first week of life was also studied. Total blood pool of free carnitine (FC), acylcarnitines (AC) and total carnitine (TC) were analysed in whole cord blood and postnatally in capillary blood obtained at the day 4-6 in 33 term newborns and at the day 7-10 in 27 preterm newborns using tandem mass spectrometry. Plasma level of carnitine in the cord blood was measured using radioenzymatic method. Cord plasma levels of FC, AC and TC were higher in preterm newborns in comparison with term newborns (p < 0.01), but the total blood pool of FC and TC in whole cord blood was lower in preterm newborns than in term newborns (p < 0.01) and positive correlation was found between FC and gestational age or birth weight (p < 0.05). In addition, positive correlation was found between AC and red blood cell count or haematocrit (p < 0.05). During the first week of life, blood pool of FC and TC in term newborns and AC and TC in preterm newborns decreased regardless of the type of enteral or parenteral nutrition. Our results indicate that preterm newborns are born with limited carnitine store. Interpretation of carnitine analyses in whole blood relies in addition to gestational age and birth weight on the haematocrit, especially in newborns with anaemia or blood hyperviscosity.
Evaluation of carnitine nutritional status in full-term newborn infants
Early Human Development, 1998
Carnitine supplements may be advisable not only in premature but also in artificially-fed full-term babies. The acyl-carnitine / free carnitine (AC / FC) and FC / total carnitine (FC / TC) ratios have been considered markers of ''carnitine insufficiency'' and ''carnitine deficiency'', respectively. Values of AC / FC. 0.40 are considered abnormal and mean that FC has a low bioavailability to the cells and so reflects a ''carnitine insufficiency''. Values of FC / TC , 0.7 indicate ''carnitine deficiency''. We analyze the validity of such ratios and the limits for them in three groups of full-term neonates (n 5 66): 22 breast-fed (BF), 22 with formula (F); and 22 fed with carnitine-supplemented formula. Several studies have shown the need to give supplements of carnitine to the neonate because of its ''essentiality'', but no one has demonstrated the adequate dosages. We therefore propose to establish new limit levels for these ratios to control carnitine nutritional status in neonates, based on the control of percentile th rd
Neonatal Blood Carnitine Concentrations: Normative Data by Electrospray Tandem Mass Spectometry
Pediatric Research, 2003
Despite a number of published reports, there is limited information about carnitine metabolism in the newborn. To establish normative data, we analyzed whole-blood carnitine concentrations in 24,644 newborns at age 1.85 Ϯ 0.95 d and umbilical cord whole blood and plasma carnitine concentrations in 50 full-term newborns. Total carnitine (TC), free carnitine (FC), and acylcarnitine (AC) were measured by electrospray tandem mass spectrometry. AC/FC ratios were derived from these measurements. The entire cohort was stratified according to TC values into a middle TC group representing 90% of the population and lower and upper TC groups representing 5% of the population, respectively. Normative data were derived from the middle TC group of full-term infants (N ϭ 19,595). TC was 72.42 Ϯ 20.75 M, FC was 44.94 Ϯ 14.99 M, AC was 27.48 Ϯ 8.05 M, and AC/FC ratio was 0.64 Ϯ 0.19 (ϮSD). These values differed significantly from umbilical cord whole blood TC values of 31.27 Ϯ 10.54 M determined in 50 samples. No meaningful correlation was found between TC and gestational age or birth weight in any group. In controlled analyses, prematurity was not associated with TC levels, whereas low birth weight (Ͻ2500 g) and male sex were significantly associated with higher TC levels. The association of low birth weight with higher TC values may be related to decreased tissue carnitine uptake. The sex effect may be related to hormonal influences on carnitine metabolism. Our study provides normative data of carnitine values measured by the highly precise method of electrospray tandem mass spectrometry in a large cohort of newborns and provides the basis for future studies of carnitine metabolism in health and disease states during the neonatal period. 829, 2003) Abbreviations MS-MS, electrospray tandem mass spectrometry TC, total carnitine FC, free carnitine AC, acylcarnitine RBC, red blood cells OR, Odds ratio CI, 95% confidence interval RE, radioenzyme ABSTRACT 823 RE: 29.39 Ϯ 14.99 MS: 29.80 Ϯ 7.63 RE: 13.99 Ϯ 11.16 MS: 9.98 Ϯ 6.54 Intermediate values set (N ϭ 19) FC Ն 46.0, FC Յ 75.9 RE: 49.67 Ϯ 17.81 MS: 71.02 Ϯ 16.54
Journal of Pediatric Gastroenterology & Nutrition, 2013
Objective: The aim of the study was to compare plasma carnitine profiles in fortified human milk (HM)-fed preterm infants or formula-fed preterm infants. Methods: Plasma acylcarnitine concentrations were determined in 20 formula-fed and 18 HM-fed preterm infants (birth weights between 1000 and 2200 g) by isotope dilution ESI MS/MS technique on study days 0, 14, and 28. Results: Concentrations of free carnitine (FC) and different acylcarnitines did not change during the 4 weeks of the study in infants fed HM. In contrast, in infants fed formula FC increased markedly (day 0: 29.989 [16.646] mmol/L, median [interquartile range], day 14: 43.972 [8.455], P < 0.05) along with increases of short-chain esters (C2 day 0: 5.300 [3.272], day 14: 6.773 [2.127], P < 0.05; C3 day 0: 0.070 [0.059], day 14: 0.110 [0.069], P < 0.05). In contrast, some medium-chain (C8:1, C12) and long-chain esters (C14, C16) decreased significantly in infant formula by day 14, whereas FC and C2 and C3 esters increased further by day 28 (FC: 47.672 [14.753], C2: 7.430 [4.688], C3: 0.107 [0.047]). Conclusions: The altered carnitine ester profile likely reflects active involvement of the carnitine molecule in the buffering, metabolism, and elimination of nonphysiological acyl moieties.