Carnitine deficiency in premature infants receivingtotal parenteral nutrition: Effect of l-carnitine supplementation

Schmidt-Sommerfeld, Eberhard; Penn, Duna; Wolf, Harald

doi:10.1016/s0022-3476(83)80027-4

Cited by 91 publications

(48 citation statements)

References 20 publications

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“…Gestational ages may vary from 22 to 36 wk, and individually delayed enteral feedings require a repeated metabolic screening after 2-4 wk. Normal values for free carnitine and acylcarnitines in premature infants published so far are restricted either to measurements within the first postnatal days (5, 7), small numbers of patients (9, 10), measurements at different postnatal ages (11)(12)(13)(14), or gestational age above 28 wk (15,16).…”

Section: Discussionmentioning

confidence: 99%

Acylcarnitine Profiles of Preterm Infants Over the First Four Weeks of Life

et al. 2002

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Measurement of free carnitine and acylcarnitines allows the detection of several inborn errors of metabolism in neonatal screening. Because available data for premature infants is limited, we studied longitudinal changes in acylcarnitine profiles of full-term and preterm neonates over the first 4 weeks of life. One hundred twenty infants were divided into four groups of 30: A, gestational age 22 to 27 wk; B, 28 to 31 wk; C, 32 to 36 wk; and D, 37 to 41 wk. Blood samples spotted on a Guthrie card were taken on days 5 and 28. Additional specimens (groups A and B only) were collected on days 1, 3, 7, and 14. Carnitine and its acyl esters were detected by looking for the precursor ions of m/z ϭ 85 using a PE Sciex API 365 electrospray ionization tandem mass spectrometer. Concentrations of free carnitine and most acylcarnitines were significantly higher in group A compared with group D postnatally. Groups B and C displayed intermediate values. Carnitine levels in infants from group A and B decreased steadily from day 1 to day 7, and recovered up to day 14 in group B only. On day 28 carnitine concentrations had further decreased in group A, while reaching postnatal levels again in group B. Postnatal carnitine levels are higher in very immature preterm infants compared with full-term infants, but become lower on day 28. However, the commonly used metabolite ratios should still allow the detection of inborn errors of metabolism. Determination of acylcarnitines by means of tandem mass spectrometry (MS/MS) is of increasing importance in the screening for disorders of inborn errors of metabolism (1-3). Metabolic screening is also applied to preterm infants, although normal ranges are not yet established. However, carnitine levels in cord blood measured by MS/MS differed between term and preterm infants (4). Another study reported increased postnatal plasma and RBC carnitine levels in preterm infants (5). No sufficient data about dried blood spot acylcarnitine profiles in premature neonates are available so far. Especially in very immature preterm infants, initiation of enteral feeding is often delayed, and total or partial parenteral nutrition is needed for a considerable period of time. Several studies have shown that carnitine levels decrease with total parenteral nutrition in term (6) as well as in preterm infants (7). Therefore, screening for inborn errors of metabolism of preterm infants, e.g. in Germany, is repeated after 2-4 wk, when oral feeding is well established (8). In this study, we investigated carnitine levels longitudinally in premature neonates by means of MS/ MS, including very immature infants (gestational age from 22 wk) during the first 4 weeks of postnatal life to test the need of individual normal ranges for metabolic screening. METHODSSolvents, reagents and internal standards. High-purity grade methanol was obtained from Merck (Darmstadt, Germany). Butanolic HCl (3 M) was prepared from high purity butanol (Merck) and HCl-gas. Stable isotopes used as internal standards were obtained from Neo Gen Scre...

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Section: Discussionmentioning

confidence: 99%

Acylcarnitine Profiles of Preterm Infants Over the First Four Weeks of Life

et al. 2002

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“…The uptake of carnitine by different organs is determined by tissue-specific fluxes from the plasma (5,32). Plasma concentrations are influenced by diet as well as de novo synthesis, and deficiency states due to poor dietary intake in neonates (33), as well as apparently impaired production of carnitine (13), have been reported.…”

Section: Discussionmentioning

confidence: 99%

Plasma and muscle free carnitine deficiency due to renal Fanconi syndrome.

Bernardini¹,

Rizzo²,

Dalakas³

et al. 1985

J. Clin. Invest.

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Plasma and urine free and acyl carnitine were measured in 19 children with nephropathic cystinosis and renal Fanconi syndrome. Each patient exhibited a deficiency of plasma free carnitine (mean 11.7±4.0 [SDI nmol/ml) compared with normal control values (42.0±9.0 nmol/ml) (P < 0.001). Mean plasma acyl carnitine in the cystinotic subjects was normal. Four subjects with Fanconi syndrome but not cystinosis displayed the same abnormal pattern of plasma carnitine levels; controls with acidosis or a lysosomal storage disorder (Fabry disease), but not Fanconi syndrome, had entirely normal plasma carnitine levels. Two postrenal transplant subjects with cystinosis but without Fanconi syndrome also had normal plasma carnitine levels. Absolute amounts of urinary free carnitine were elevated in cystinotic individuals with Fanconi syndrome. In all 21 subjects with several different etiologies for the Fanconi syndrome, the mean fractional excretion of free carnitine (33%) as well as acyl carnitine (26%) greatly exceeded normal values (3 and 5%, respectively). Total free carnitine excretion in Fanconi syndrome patients correlated with total amino acid excretion (r = 0.76). Two cystinotic patients fasted for 24 h and one idiopathic Fanconi syndrome patient fasted for 5 h showed normal increases in plasma fl-hydroxybutyrate and acetoacetate, which suggested that hepatic fatty acid oxidation was intact despite very low plasma free carnitine levels. Muscle biopsies from two cystinotic subjects with Fanconi syndrome and plasma carnitine deficiency had 8.5 and 13.1 umol free carnitine per milligram of noncollagen protein, respectively (normal controls, 22.3 and 17.1); total carnitines were 11.8 and 13.3 nmol/mg noncollagen protein (controls 33.5, 20.0). One biopsy revealed a mild increase in lipid droplets. The other showed mild myopathic features with variation in muscle fiber size, small vacuoles, and an increase in lipid droplets. In renal Fanconi syndrome, failure to reabsorb free and acyl carnitine results in a secondary plasma and muscle free carnitine deficiency.

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“…No transfer of palmitoylcarnitine [present in plasma in small amounts (28)] could be detected. This may be partly due to the strong binding of palmitoylcarnitine to albumin (Schmidt-Sommerfeld E, unpublished data), and possibly also to placental tissue protein, suggested by the large placental uptake of palmitoylcarnitine during perfusion.…”

Section: Discussionmentioning

confidence: 99%

Transfer and Metabolism of Carnitine and Carnitine Esters in the in Vitro Perfused Human Placenta

et al. 1985

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ABSTRAa. The transfer and metabolism of L-carnitine, L-acetylcarnitine, and L-palmitoylcarnitine were studied in the human placenta at term by means of in vitro dual perfusion of a placental lobe. L-Carnitine transfer was 20% that of the freely diffusing antipyrine and 40% that of Llysine. The transfer of L-acetylcarnitine was similar to that of ccarnitine, but no placental transfer of L-palmitoylcarnitine was found. In contrast to L-lvsine. L-carnitine. and -,

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Carnitine deficiency in premature infants receivingtotal parenteral nutrition: Effect of l-carnitine supplementation

Cited by 91 publications

References 20 publications

Acylcarnitine Profiles of Preterm Infants Over the First Four Weeks of Life

Acylcarnitine Profiles of Preterm Infants Over the First Four Weeks of Life

Plasma and muscle free carnitine deficiency due to renal Fanconi syndrome.

Transfer and Metabolism of Carnitine and Carnitine Esters in the in Vitro Perfused Human Placenta

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