Total Carnitine Research Articles

Effect of levocarnitine supplementation on myocardial strain in children with acute kidney injury receiving continuous kidney replacement therapy: a pilot study.

Carnitine plays a key role in energy production in the myocardium and is efficiently removed by continuous kidney replacement therapy (CKRT). Effects of levocarnitine supplementation on myocardial function in children receiving CKRT have not been investigated. This controlled pilot cohort study of 48 children investigated effects of levocarnitine supplementation on myocardial strain in children receiving CKRT for acute kidney injury (AKI). Children (n = 9) with AKI had total (TC) and free plasma carnitine (FC) measurements and echocardiogram for longitudinal and circumferential strain at baseline (prior to CKRT) and follow-up (on CKRT for > 1 week with intravenous levocarnitine supplementation, 20 mg/kg/day). Intervention group was compared with three controls: (1) CKRT controls (n = 10) received CKRT > 1 week (+AKI, no levocarnitine), (2) ICU controls (n = 9) were parenteral nutrition-dependent for > 1 week (no AKI, no levocarnitine), and (3) healthy controls (n = 20). In the Intervention group, TC and FC increased from 36.0 and 18 μmol/L to 93.5 and 74.5 μmol/L after supplementation. TC and FC of unsupplemented CKRT controls declined from 27.2 and 18.6 μmol/L to 12.4 and 6.6 μmol/L, which was lower vs. ICU controls (TC 32.0, FC 26.0 μmol/L), p < 0.05. Longitudinal and circumferential strain of the Intervention group improved from - 18.5% and - 18.3% to - 21.1% and - 27.6% after levocarnitine supplementation; strain of CKRT controls (-14.4%, -20%) remained impaired and was lower vs. Intervention and Healthy Control groups at follow-up, p < 0.05. Levocarnitine supplementation is associated with repletion of plasma carnitine and improvement in myocardial strain and may benefit pediatric patients undergoing prolonged CKRT.

Carnitine status before and after paracentesis in patients with ascites and liver cirrhosis and improvement of subjective symptoms by intravenous administration of carnitine ― Initial study

Carnitine status before and after paracentesis in patients with ascites and liver cirrhosis and improvement of subjective symptoms by intravenous administration of carnitine ― Initial study

Carnitine chloride reduces the severity of experimental hyperhomocysteinemia and promotes lactate utilization by mitochondrial fraction of the rat epididymis

Hyperhomocysteinemia is a risk factor for many diseases, including reproductive disorders in men. L-carnitine is used in medical practice to correct impaired bioenergetic conditions; in patients with idiopathic forms of infertility its effects are associated with improvement of the sperm parameters. However, the effect of exogenous L-carnitine on the level of homocysteine in the gonadal tissues, as a risk factor for impaired fertility, has not been investigated yet. The aim of this study was to investigate activity of bioenergetic enzymes in the epididymal mitochondrial fraction, the dynamics of changes in the cytoplasmic and mitochondrial lactate levels and LDH activity, the total carnitine content, as well as the oxidative status of these cells under conditions of oxidative stress caused by hyperhomocysteinemia, and to assess the effect of carnitine chloride on these parameters under conditions of methionine administration to male Wistar rats. Methionine administration to animals for three weeks at a dose of 3 g/kg, resulted in development of the severe forms of hyperhomocysteinemia with serum homocysteine concentrations exceeding 100 μmol/L. This was accompanied by a decrease in the activity of enzymes involved in the bioenergetic processes of the cell: tissue respiration (succinate dehydrogenase) and oxidative phosphorylation (H+-ATPase) in the epididymal head and tail. The change in lactate metabolism included an increase in its level in both the mitochondrial and cytoplasmic fractions of the epididymal head and mitochondria of the epididymal tail, and also simultaneous statistically significant decrease in LDH activity in the mitochondria and cytoplasm of the epididymal head. In male rats with severe hyperhomocysteinemia, an increase in the activity of mitochondrial SOD accompanied by an increase in the carbonylation of mitochondrial proteins in the head and tail of the epididymis was noted. Modeling of hyperhomocysteinemia under conditions of carnitine chloride of administration led to different reactions of the cells of the studied tissues assayed in the epididymal head and tail homogenate. In the epididymal head, carnitine chloride promoted an increase in the mitochondrial lactate concentration and a decrease in the cytoplasmic lactate concentration, as well as an increase in the LDH activity associated with the mitochondrial fraction. These changes were accompanied by an increase in the activity of H+-ATPase in the epididymal, thus suggesting that carnitine chloride stimulated lactate transport of into the mitochondria and its use as an energy substrate under conditions of oxidative stress caused by hyperhomocysteinemia. In the tail tissues, the changes were protective in nature and were associated with a decrease in the formation of oxidatively modified proteins.

Astımlı çocuklarda leptin, adiponektin ve karnitin düzeylerinin akciğer fonksiyonları, astım şiddeti ve BMI ile ilişkisinin değerlendirilmesi

Purpose: The aim of this study is to evaluate the relationship between serum levels of leptin, adiponectin and carnitine with lung function, disease severity and BMI (Body Mass Index) in children with asthma. Materials and methods: 97 Pediatric patients with not in acute attack period bronchial asthma and 40 healthy control subjects were included in the study. Pulmonary function tests done to all asthma patients with a spirometer. Children with asthma were divided into 3 groups according to GINA criteria, mild intermittent, mild persistent, and moderate persistent, with using symptoms and spirometric parameters according to the severity of airway obstruction. Leptin, total carnitine and adiponectin analyzes were performed from venous blood by ELISA method. Results: Patient group serum leptin values were found to be significantly higher than the control group serum leptin values (p = 0.001). Patient group serum total carnitine values were found to be significantly lower than the control group (p = 0.001). Moderate persistent group adiponectin and total carnitine values were found to be significantly lower than mild intermittent group (p <0.05). A weak negative correlation was found between leptin and total carnitine, eosinophil, BMI values. A weak negative correlation was found between total carnitine and eosinophil, BMI values. A moderate negative correlation was found between age and leptin, adiponectin, total carnitine values. Conclusions: It suggested that leptin levels increased, adiponectin and total carnitine levels decreased in children with asthma and at the same time the decrease in adiponectin and total carnitine levels may be associated with disease severity.

Effect of L-carnitine on health-related quality of life in patients with liver cirrhosis.

L-carnitine (4-N-trimethylammonium-3-hydroxybutyric acid) is the physiologically active form of carnitine and is a natural compound that has been shown to exhibit antioxidant activity. L-carnitine is used as a supplementary treatment in patients with cirrhosis with hepatic encephalopathy, hyperammonemia or muscle cramps. In the present study, the effect of L-carnitine supplementation on health-related quality of life in 30 patients with cirrhosis was prospectively examined. L-carnitine (1,800 mg/day) was administered orally for 6 months. To assess the effects of L-carnitine on chronic fatigue, patients filled out a self-report questionnaire regarding their physical and mental health. The levels of total and free carnitine, and acylcarnitine were found to be significantly higher 1, 3 and 6 months after therapy initiation compared with before treatment. Serum albumin levels were significantly increased 3 and 6 months after initiation of therapy. L-carnitine supplementation significantly increased the BAP/d-ROM ratio, a marker of antioxidant status in patients with cirrhosis. Changes in serum carnitine concentrations were positively correlated with changes in serum albumin levels (R2=0.369; P=0.012), but not with changes in serum ammonia levels (R2= 0.005; P=0.78). Total and mental health scores improved significantly, and physical scores improved marginally 3 and 6 months after initiation of L-carnitine. These findings may be attributed to the enhanced serum albumin levels and oxidative stress rather than the reduced serum ammonia levels. Based on these results, it is suggested that L-carnitine can potentially alleviate chronic fatigue, along with the increased BAP/d-ROM ratio, which were involved in increased oxidative stress in patients with cirrhosis. The specific mechanisms by which L-carnitine ameliorates chronic fatigue is not fully understood and requires further investigation.

Biochemical phenotype and its relationship to treatment in 16 individuals with PCCB c.1606A > G (p.Asn536Asp) variant propionic acidemia

Propionic acidemia (PA) is caused by inherited deficiency of mitochondrial propionyl-CoA carboxylase (PCC) and results in significant neurodevelopmental and cardiac morbidity. However, relationships among therapeutic intervention, biochemical markers, and disease progression are poorly understood. Sixteen individuals homozygous for PCCB c.1606A > G (p.Asn536Asp) variant PA participated in a two-week suspension of therapy. Standard metabolic markers (plasma amino acids, blood spot methylcitrate, plasma/urine acylcarnitines, urine organic acids) were obtained before and after stopping treatment. These same markers were obtained in sixteen unaffected siblings. Echocardiography and electrocardiography were obtained from all subjects. We characterized the baseline biochemical phenotype of untreated PCCB c.1606A > G homozygotes and impact of treatment on PCC deficiency biomarkers.Therapeutic regimens varied widely. Suspension of therapy did not significantly alter branched chain amino acid levels, their alpha-ketoacid derivatives, or urine ketones. Carnitine supplementation significantly increased urine propionylcarnitine and its ratio to total carnitine. Methylcitrate blood spot and urine levels did not correlate with other biochemical measures or cardiac outcomes. Treatment of PCCB c.1606A > G homozygotes with protein restriction, prescription formula, and/or various dietary supplements has a limited effect on core biomarkers of PCC deficiency. These patients require further longitudinal study with standardized approaches to better understand the relationship between biomarkers and disease burden.

Intramuscular short-chain acylcarnitines in elderly people are decreased in (pre-)frail females, but not in males.

This study tested the hypothesis that in human aging, a decreased intramuscular acylcarnitine status is associated with (pre-)frailty, reduced physical performance, and altered mitochondrial function. We used a cross-sectional study design with well-matched fit and (pre-)frail old males and females, using young males and females as healthy controls. Frailty was assessed according to the Fried criteria and physical performance was determined by 400m walk test, short physical performance battery and handgrip strength. Muscle and plasma acylcarnitine status, and muscle mitochondrial gene expression was analyzed. Results showed that intramuscular total carnitine levels and short-chain acylcarnitine levels were lower in (pre-)frail old females compared to fit old females and young females, whereas no differences were observed in males. The low intramuscular short-chain acylcarnitine levels in females correlated with low physical performance, even after correction for muscle mass (%), and were accompanied with lowered expression of genes involved in mitochondrial energy production and functionality. It is, therefore, concluded that in (pre-)frail old females, intramuscular total carnitine levels and short-chain acylcarnitine levels are decreased, and this decrease is associated with reduced physical performance and low expression of a wide range of genes critical for mitochondrial function. The results stress the importance of taking sex differences into account in aging research.

Sorafenib Might Induce Sarcopenia in Patients With Hepatocellular Carcinoma by Inhibiting Carnitine Absorption.

Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of cancers. Sorafenib, an oral multi-target TKI, improves the median overall survival time in patients with hepatocellular carcinoma (HCC). It also inhibits the absorption of carnitine by down-regulating the human organic cationic transporter OCTN2 located largely in the small intestinal mucosa and skeletal muscle. The aim of the study was to determine, by assessing carnitine metabolism, whether sarcopenia is induced in patients with HCC who are receiving sorafenib. This retrospective study included 110 adult Japanese patients with liver cirrhosis and HCC who received sorafenib. Sorafenib was administered at a dose of 200-800 mg/day for 4 weeks. Blood samples were collected before and after treatment, and serum carnitine fraction and myostatin levels were measured. Cross-sectional areas (cm2) of the skeletal muscles at the third lumbar vertebra level were determined by manually outlining computed tomography images before and after treatment. The cross-sectional areas were normalized for height [skeletal muscle index (SMI), cm2/m2]. Patients were allocated to two groups according to Child-Pugh (CP) class; 81 had CP-A liver function, and 29 had CP-B. SMI after treatment was significantly lower than that before treatment in both groups. Serum levels of total carnitine and free carnitine after treatment were significantly lower than those before treatment in both groups. There were no differences in serum levels of myostatin before and after treatment in either group. Sorafenib might decrease serum levels of carnitine by inhibiting carnitine absorption. Decreasing of serum levels of carnitine might lead to presarcopenia.

Hepcidin and its Related Hematological Biomarkers of Anemia in Children on Hemodialysis: Role of Carnitine Deficiency

BACKGROUND: Anemia is one of the most common complications in end-stage renal disease (ESRD) patients. Hepcidin is a hormone that regulates iron homeostasis in patients with ESRD. Carnitine deficiency is commonly seen in hemodialysis (HD) patients.&#x0D; AIM: This study aimed to investigate the relationship between hepcidin and inflammatory and other anemia markers in children with ESRD and to evaluate the association of carnitine deficiency with anemia in these patients.&#x0D; SUBJECTS AND METHODS: Thirty pediatric patients with ESRD undergoing HD, and thirty healthy, age- and sex-matched children served as controls were included in the study. Serum levels hepcidin, iron status, high-sensitivity C-reactive protein, and total carnitine were measured.&#x0D; RESULTS: Statistically significant increases in serum levels of hepcidin (100.7 ± 0.99 ng\ml vs. 77.43 ± 0.8 ng\ml, p = 0.000), was found in HD children as compared to healthy controls. Statistically significant increase in serum levels of hs-CRP (3.94 ± 0.19 mg/l vs. 1.36 ± 0.07 mg/l, p = 0.04) was found in HD children as compared to healthy controls. However, serum levels of carnitine (29.59 ± 2.46 μmol/L vs. 36 ± 2.39 μmol/L, p = 0.000) showed statistically significant decreases in HD children as compared to healthy controls positive correlation was found between hepcidin and hs-CRP (r = 0.059, p = 0.042). Furthermore, a positive correlation was present between serum carnitine levels and serum iron levels (r = 0.651, p = 0.042).&#x0D; CONCLUSION: Serum hepcidin may be a more useful biomarker of functional iron deficiency in children on HD. The efficacy of carnitine treatment for children on HD with carnitine deficiency and its effect on anemia needs to be studied.

Determination of Free and Total Choline and Free and Total Carnitine in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography/Tandem Mass Spectrometry (HPLC-MS/MS): A Multi-laboratory Testing Study, Final Action 2015.10.

A multi-laboratory study was conducted on AOAC First Action Method 2015.10 "Determination of Free and Total Choline and Free and Total Carnitine in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography/Tandem Mass Spectrometry (HPLC-MS/MS)." In this study, nine laboratories participated in the performance testing of the method using ten nutritional products tested as blind duplicates. Both free and total carnitine and free and total choline content of the samples were determined using separate extractions for the free and total results. For free choline and carnitine analysis, samples are diluted in water. For total choline and carnitine analysis, samples are extracted using acid-assisted microwave hydrolysis with nitric acid. For both the free and total methods, samples are then diluted with acetonitrile and analyzed using strong cation exchange (SCX) liquid chromatography coupled to a triple quadrupole tandem mass spectrometer (LCMS). Stable isotope labeled internal standards were utilized in all analyses to compensate for extraction inefficiencies and ionization suppression.

Association Between the Serum Carnitine Level and Ammonia and Valproic Acid Levels in Patients with Bipolar Disorder.

Valproic acid (VPA) is not only an antiepileptic drug but also a mood stabilizer for patients with bipolar disorder. Long-term VPA therapy can cause carnitine deficiency, which may result in an increase in the blood ammonia level, in patients with epilepsy. However, information about this effect in patients with bipolar disorder is limited. The aim of this study was to investigate the associations between the serum VPA level and the carnitine and ammonia levels in psychiatric adult patients with epilepsy. The subjects were 182 consecutive Japanese adult patients (mean age 54.3 ± 19.5 years) diagnosed with bipolar disorder and treated with VPA. The serum VPA level, carnitine fraction, and plasma ammonia level were measured. Furthermore, the free carnitine and acylcarnitine fractions were measured using an enzyme cycling method. Sixty-nine patients (38%) had a low free carnitine level. There were significant differences in sex, height, VPA dose, serum VPA level, total carnitine level, acylcarnitine level, and acylcarnitine/free carnitine ratio between patients with a low free carnitine level and those with a normal range of free carnitine. The simple and multiple regression analyses revealed that the VPA dose and the serum VPA level were inversely and significantly correlated with the free carnitine level. The plasma ammonia level was correlated with the VPA dose, serum VPA level, and acylcarnitine level but not with the free carnitine level. These findings suggest that carnitine deficiency is associated with the VPA dose and the serum VPA level in patients with bipolar disorder. However, it is unlikely that carnitine deficiency is associated with hyperammonemia in patients with bipolar disorder.

MON-065 Prevention of 6-Mercaptopurine-Induced Hypoglycemia by Levocarnitine Replacement

Background: Symptomatic hypoglycemia has been reported in children less than 6 years of age receiving 6-Mercaptopurine for acute lymphoblastic anemia (ALL); however, the mechanism of 6-Mercaptopurine-induced hypoglycemia has been unclear. Objective: The objective was to investigate the metabolism in a 3-year-old patient with hypoglycemia induced by 6-Mercaptopurine during maintenance therapy for ALL. Methods: We reviewed test results including serum total and free carnitine levels at time of hypoglycemia in a 3-year-old child with ALL who had repeatedly low plasma glucose as a side effect of 6-Mercaptopurine. Hypoglycemia defined as plasma glucose <50 mg/dL was detected using a glucose meter and each time verified in the clinical laboratory. After Levocarnitine was added to 6-Mercaptopurine therapy, the glycemic control was assessed using a glucose meter, the clinical laboratory, and a continuous glucose monitor; serum total and free carnitine levels were repeated when hypoglycemia resolved. Results: Our patient presented with fatigue, tremors and plasma glucose 39 mg/dL to 47 mg/dL, corrected with a sugary beverage. He had plasma ACTH 38 pg/mL, serum cortisol 10 mcg/dL, total carnitine 24 nmol/mL (expected 35 - 84), free carnitine 18 nmol/mL (expected 24 - 63), plasma free fatty acids 1.62 mmol/L (expected >1.5), beta-hydroxybutyrate of 0.2 mmol/L to 0.7 mmol/L (expected >2.0), and urine ketone bodies negative when plasma glucose was between 33 mg/dL and 39 mg/dL. Plasma insulin was undetectable at time of hypoglycemia, and serum glucose increased by less than 30 points in response to Glucagon IV. Serum IGF-1 as measure of growth hormone effect and thyroid function were normal. Hypoglycemia continued to daily recur especially during the night despite bedtime snacks high in complex carbohydrates and was prevented only by Levocarnitine 25 mg/kg/dose every 12 hours PO that raised serum total and free carnitine levels. The patient remained hypoglycemia-free one month after Levocarnitine was added to 6-Mercaptopurine therapy, in particular, he had average glucose 114 mg/dL with standard deviation 30 mg/dL, glucose 70 mg/dL to 140 mg/dL 93% of the time, and glucose <55 mg/dL 0% of the time. Conclusions: Our patient had symptomatic hypoketotic hypoglycemia related to moderately reduced serum total and free carnitine, corrected with Levocarnitine replacement. Increase in plasma free fatty acids without expected increase in plasma and urine ketone bodies may be sign of impaired synthesis of carnitine, which is required for transport of fatty acids into the mitochondria to produce ketone bodies. Measuring serum total and free carnitine in hypoglycemia induced by 6-Mercaptopurine is helpful in identifying children, who may benefit from Levocarnitine replacement.

Liver-Oriented Acute Metabolic Effects of A Low Dose of L-Carnitine under Fat-Mobilizing Conditions: Pilot Human Clinical Trial.

The acute metabolic effect of low dosages of L-carnitine under fat-mobilizing conditions was investigated. Healthy subjects (Study 1: n=5; Study 2: n=6) were asked to fast overnight. Then, 30 min of aerobic exercise on a cycle ergometer was performed after supplementation, followed by a 3.5-h sedentary recovery phase. The following ingestion patterns were used: Study 1 (i) noningestion, (ii) 750 mg of L-carnitine (LC), and (iii) 750 mg of LC+50 g of carbohydrate (CHO); Study 2 (iv) noningestion, (v) 500 mg of LC, (vi) 30 mg of CoQ10, and (vii) 500 mg of LC+30 mg of CoQ10. The energy expenditure (EE) and nonprotein respiratory quotient (npRQ) were measured during the pre-exercise, postexercise, and recovery periods. Serum free carnitine, acetylcarnitine, total carnitine (Study 1 and 2), and ketone bodies (Study 2) were measured. The 750 mg LC treatment significantly facilitated fat oxidation during the recovery phases (p<0.05) without elevating EE. The higher fat oxidation associated with LC was completely suppressed by CHO. CoQ10 affected neither npRQ nor EE. npRQ was significantly correlated with the serum total ketone bodies (R=-0.68, p<0.001) and acetylcarnitine (R=-0.61--0.70, p<0.001). The highest correlation was found between acetylcarnitine and total ketone bodies immediately after exercise (R=0.85, p<0.001). In conclusion, LC enhanced liver fat utilization and ketogenesis in an acute manner without stimulating EE under fat-mobilizing conditions.

Mass Spectrometric Analysis of L-carnitine and its Esters: Potential Biomarkers of Disturbances in Carnitine Homeostasis.

Purpose: After a golden age of classic carnitine research three decades ago, the spread of mass spectrometry opened new perspectives and a much better understanding of the carnitine system is available nowadays. In the classic period, several human and animal studies were focused on various distinct physiological functions of this molecule and these revealed different aspects of carnitine homeostasis in normal and pathological conditions. Initially, the laboratory analyses were based on the classic or radioenzymatic assays, enabling only the determination of free and total carnitine levels and calculation of total carnitine esters’ amount without any information on the composition of the acyl groups. The introduction of mass spectrometry allowed the measurement of free carnitine along with the specific and sensitive determination of different carnitine esters. Beyond basic research, mass spectrometry study of carnitine esters was introduced into the newborn screening program because of being capable to detect more than 30 metabolic disorders simultaneously. Furthermore, mass spectrometry measurements were performed to investigate different disease states affecting carnitine homeostasis, such as diabetes, chronic renal failure, celiac disease, cardiovascular diseases, autism spectrum disorder or inflammatory bowel diseases.Results: This article will review the recent advances in the field of carnitine research with respect to mass spectrometric analyses of acyl-carnitines in normal and various pathological states.Conclusion: The growing number of publications using mass spectrometry as a tool to investigate normal physiological conditions or reveal potential biomarkers of primary and secondary carnitine deficiencies shows that this tool brought a new perspective to carnitine research.

Comparison of LC-MS/MS and Enzymatic Methods for the Determination of Total Choline and Total Carnitine in Infant Formula and Milk Products.

Choline and l-carnitine are classified as pseudo-vitamins because of their conditionally essential status. As they are involved in multiple physiological metabolic pathways in the human body, they are routinely fortified in infant and adult nutritional formulas. The performance of an LC-MS/MS method for the analysis of choline and carnitine, compared with enzymatic methods in routine use for the analysis of total carnitine and total choline, is described. Powder samples were reconstituted, with release of carnitine and choline facilitated by both acid and alkaline hydrolysis and the extract analyzed by LC-MS/MS. Quantitation was by internal standard technique using deuterium-labeled carnitine and deuterium-labeled choline. Method range, specificity, sensitivity, precision, recovery, accuracy, and ruggedness were assessed for milk powders, infant formulas, and soy- and milk-based nutritional products. Spike recoveries of 94.0-108.4% were obtained for both total carnitine and choline, and no statistical bias (α = 0.05) between measured results and certified values (choline: P = 0.36; free carnitine: P = 0.67) was found for NIST 1849a certified reference material (NIST1849a). Precision, as repeatability relative standard deviation (RSD), was 2.0% RSDr for total carnitine and 1.7% RSDr for total choline. Equivalent results for total choline and total carnitine were obtained by LC-MS/MS and enzymatic methods (n = 30). The described LC-MS/MS method is fit for purpose for routine product compliance release testing environments. This validation study has confirmed that alternative enzymatic assays can be used with confidence in laboratories in which LC-MS/MS platforms are unavailable. An LC-MS/MS method was evaluated and found to be fit-for-purpose for routine product compliance release testing of infant formula. The LC-MS/MS method was compared with enzymatic methods for the analysis of total carnitine and total choline. Alternative enzymatic assays can be used with confidence in laboratories in which LC-MS/MS platforms are unavailable.

Effects of the Menstrual Cycle on Serum Carnitine and Endurance Performance of Women.

This study aimed to investigate the effect of the menstrual cycle on serum carnitine and the endurance performance of healthy women. Fifteen eumenorrheic women underwent cycle ergometer exercise at 60% maximal oxygen uptake (V̇ O2max) for 45 min, followed by exercise at an intensity that was increased to 80% V̇ O 2max until exhaustion, during two menstrual cycle phases, including the early follicular phase (FP) and the midluteal phase (LP). The blood levels of estradiol, progesterone, total carnitine, free carnitine, and acylcarnitine were assessed. Compared with the FP, the LP had significantly lower serum total carnitine (p<0.05) and free carnitine (p<0.01). Moreover, the group with decreased endurance performance in the LP than in the FP showed a significantly higher change in serum free carnitine compared with the group that showed improved endurance performance in the LP than in the FP (p<0.05). The results of this study suggested that the changes in serum free carnitine during the menstrual cycle might influence endurance performance.

Carnitine Profile Changes in Pediatric Hematopoietic Stem Cell Transplant: New Role for Carnitine?

Carnitine is an essential cofactor for mitochondrial import and oxidation of fatty acids. High-dose chemotherapy and radiation, often required for hematopoietic stem cell transplant (HSCT), leads to tissue damage, mitochondrial dysfunction, and alterations in carnitine metabolism. The aim of this pilot cohort study was to describe plasma and urinary carnitine profiles during pediatric HSCT and their relationships with clinical outcomes. Plasma and urinary carnitine samples were collected from 22 pediatric patients before and through day 180 post-HSCT. Associations were observed between graft-versus-host disease and an elevated plasma total carnitine (P=0.019), and also increased plasma acyl:free carnitine ratio with veno-occlusive disease (P=0.016). Mortality was observed in those with their highest urinary total carnitine losses on day 0 (P=0.005), and in those with an abnormal day 28 plasma ratio either above or below the reference range (P=0.007). Changes in carnitine profiles were more reflective of metabolic stress and negative outcomes than of inadequate dietary intake. Associations observed direct larger studies to assess the validity of carnitine profiles as a prognostic indicator and also to assess whether prophylactic carnitine supplementation pre-HSCT could reduce mitochondrial injury and urinary losses and help mitigate inflammatory and metabolic comorbidities of HSCT.

Effect of L-Carnitine on Amino Acid Metabolism in Elderly Patients Undergoing Regular Hemodialysis

Introduction: Among patients regularly undergoing hemodialysis, hypocarnitinaemia often develops as a consequence of inadequate dietary intake, reduced synthesis in the body, and considerable losses during hemodialysis. Objectives: To evaluate the effects of L-carnitine supplementation on patients with end-stage kidney disease (ESKD) who underwent hemodialysis. Methods: Thirty-one patients with ESKD, comprising 18 men and 13 women, with a median age of 72 (range 58–89) years, who underwent regular hemodialysis received treatment with L-carnitine for 1 year. The total and free carnitine, acylcarnitine, and amino acids (AA) levels before and after L-carnitine treatment were analyzed, and the blood biochemistry results and clinical profiles of the subjects were compared before and after treatment. Results: The median (interquartile range [IQR]) serum total and free carnitine and acylcarnitine levels significantly increased from 34.5 (28.2–44.3), 20.9 (15.8–27.6), and 14.1 (11.2–17.6) µmol/L, respectively to 407.4 (371.6–493.5), 270.2 (228.3–316.0), and 155.0 (136.1–168.5) µmol/L, respectively, after treatment (all p < 0.001). The median (IQR) blood valine, tyrosine, phenylalanine, and citrulline levels increased from 0.94 (0.80–1.09), 0.45 (0.39–0.55), 0.61 (0.56–0.79), and 1.04 (0.79–1.26) mg/dL, respectively to 1.24 (1.13–1.54), 0.76 (0.62–0.85), 0.90 (0.70–1.04), and 1.22 (0.92–1.39) mg/dL, respectively, following L-carnitine treatment (p < 0.001, p < 0.001, p = 0.002, and p = 0.030, respectively); however, the median (IQR) blood arginine level decreased from 0.20 (0.13–0.24) to 0.09 (0.06–0.14) mg/dL after treatment (p < 0.001). The median (IQR) percentage fractional shortening (41.5 vs. 41.9%; p = 0.012) and left ventricular ejection fraction (65.2 vs. 67.3%; p = 0.036) increased significantly following treatment. Conclusions: L-Carnitine increased the blood acylcarnitine levels, enhanced fatty acid metabolism, and affected AAs metabolism; this may be beneficial for energy production within the cardiac and skeletal muscles.

Carnitine metabolism and maximum oxygen consumption in young athletes

Purpose. To assess physical performance of children doing sports on the basis of carnitine exchange indicators.Characteristics of children and research methods. The study involved 94 young athletes and 37 schoolchildren (Control Group). The researchers studied such indicators as free and bound carnitine, maximum oxygen consumption and body composition.Results. The study noted positive reliable correlations between the level of absolute maximum oxygen consumption and the content of total and free carnitine in the blood. The data obtained may indicate greater aerobic performance in athletes with a high level of free carnitine in the blood, since its sufficient amount provides adequate cellular energy exchange.Conclusion. Thus, studying the state of carnitine indicators and body composition, it is possible to predict physical performance of children and to prevent deterioration of health in children during intense physical exertion.

Manifestations of mitochondrial dysfunction in children with connective tissue dysplasia and chronic gastroduodenitis

According to the literature, signs of mitochondrial dysfunction are found in 15–20% of children in the population. It often accompanies physical illness. The digestive tract is an energy-intensive system of organs, so violations of energy metabolism affect its functioning. The aim of this study was to determine the basal level of carnitine and its fractions in children with connective tissue dysplasia and chronic gastroduodenitis and to evaluate their dynamics after L-carnitine therapy. 77 children with this somatic pathology were examined. Depending on the presence of connective tissue dysplasia, they were divided into 2 groups – the main and the comparison group. Blood levels of total and bound carnitine were determined in all patients using liquid tandem chromatomass-spectrometry. Free carnitine was calculated as the difference between total and bound. It was found that in children with connective tissue dysplasia basal levels of total carnitine and its fractions are significantly lower than in patients of the comparison group. Carnitine and fractions increased in all children after a 30-day course of therapy with L-carnitine, reaching normal values with a reduced basal level. The degree of increase in indicators was greater in patients with initially lower levels, which was observed primarily in a group with connective tissue dysplasia. This study showed that connective tissue dysplasia in most cases is accompanied by mitochondrial dysfunction. Most patients with connective tissue dysplasia and chronic gastroduodenitis require correction of energy metabolism disorders using energy-stimulating therapy.