Free Carnitine Levels Research Articles

Evaluation of plasma carnitine status in patients diagnosed with juvenile idiopathic arthritis.

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood and manifests mainly as autoinflammation of the joints and other tissues. Several treatment options such as nonsteroidal antiinflammatory drugs, methotrexate, and intra-articular steroids are widely used to relieve and improve this inflammation. Secondary carnitine deficiency can be detected in chronic diseases by either renal loss or increased demand. While carnitine status can be associated with several conditions, in the present study our aim is to determine the levels of free carnitine and acyl-carnitine in Turkish JIA patients. One hundred and fourteen patients diagnosed with juvenile idiopathic arthritis and 50 healthy individuals who served as the control group were included in the study. A fasting blood sample was collected from the children in both groups to determine free carnitine and acylcarnitine ester by quadripole electrospray tandem mass spectrometry (ESI-MS/ MS). Screening of acyl-carnitine profile revealed free carnitine, C14, C14:2, C16, C16-OH, and C18 carnitine levels were higher (p < 0.0001, p < 0.0001, p < 0.001, p < 0.001, and p = 0.011, respectively), while C2, C3, C4, C6, C8, C10, C10:1, C10:2, C3DC, C4DC, C5DC, C4-OH, and C18:1-OH carnitine levels were lower (p < 0.0001) in JIA patients in comparison to the control group. Total acyl-carnitine levels (p < 0.001) and acyl-carnitine to free carnitine ratio (p < 0.001) were also lower in JIA patients than the control group. Free carnitine levels were significantly higher (48.05 ± 13.36 μmol/L) in patients under antiinflammatory drug therapy than those who did not receive any treatment (43.18 ± 7.96 μmol/L) (p = 0.004). In the present study we were not able to define secondary carnitine deficiency in JIA patients, although free carnitine and acyl-carnitine variations were detected in JIA patients. In conclusion, routine carnitine supplementation is not recommended in all patients with JIA.

Quantification of Free and Total Carnitine in Serum Using Liquid Chromatography Tandem Mass Spectrometry.

L-carnitine is a crucial component for transporting long-chained fatty acids from the cytosol into the mitochondrial matrix for fatty acid oxidation. During this process, carnitine forms numerous acylcarnitines before being recycled into the cytosol. Abnormal levels of free carnitine, total carnitine, and acylcarnitines in serum can be indicative of a metabolic disorder before symptoms are present. A liquid chromatography tandem mass spectrometry (LC-MS/MS) method is described for the determination of free and total carnitine in serum. To measure total carnitine, samples are spiked with deuterated carnitine (internal standard) and hydrolyzed with potassium hydroxide to convert acylcarnitines to carnitine. The reaction is quenched by the addition of hydrochloric acid. Carnitine is extracted via a methanolic protein precipitation. The solution is then injected on LC-MS/MS for analysis to determine the carnitine concentration using multiple-reaction monitoring.

PROPIONYLCARNITINE AND FREE CARNITINE ARE NEW BIOMARKERS IN THE FOLLOW-UP PERIOD OF MUCOPOLYSACCARIDOSIS TO SCREEN OXIDATIVE STRESS

Objective&#x0D; There is no applicable and easy procedure to screen&#x0D; oxidative stress in mucopolysaccaridosis (MPS)&#x0D; patients. The aim herein was to show the antioxidative&#x0D; properties of free carnitine (FC) and propionylcarnitine&#x0D; (PC) with respect to oxidative markers in MPS and&#x0D; use a simple and easy method in patient follow-up.&#x0D; Material and Methods&#x0D; FC and PC were studied as an antioxidative&#x0D; marker using tandem mass spectroscopy and&#x0D; malondialdehyde (MDA) was studied as an oxidative&#x0D; marker in 27 MPS patients and 24 healthy volunteers.&#x0D; Results&#x0D; While the PC and FC levels were significantly&#x0D; decreased, the MDA levels were higher in the&#x0D; MPS patients than in the healthy volunteers.When&#x0D; compared between the enzyme-treated MPS patients&#x0D; and untreated MPS patients, there were no significant&#x0D; differences between the groups. MDA was found to&#x0D; inversely correlated with PC (r =–0.402, P=0.003).It&#x0D; was noteworthy that PC had a significant correlation&#x0D; with MDA.&#x0D; Conclusion&#x0D; The findings revealed that the affected patients had&#x0D; higher MDA levels and lower PC and FC levels,&#x0D; indicating an imbalance through the oxidative side. An&#x0D; applicable method of FC and PC measurement could&#x0D; be used to screen patients, considering them as new&#x0D; antioxidative markers in the patient follow-up period&#x0D; for the response of enzyme replacement therapy and/&#x0D; or antioxidant drugs.

Levocarnitine Supplementation Suppresses Lenvatinib-Related Sarcopenia in Hepatocellular Carcinoma Patients: Results of a Propensity Score Analysis.

This study investigated the inhibitory effect of levocarnitine supplementation on sarcopenia progression in hepatocellular carcinoma (HCC) patients treated with lenvatinib. We evaluated the skeletal muscle index (SMI). After propensity score matching for age, sex, modified albumin-bilirubin grade, baseline presence of sarcopenia, and branched-chain amino acid administration, we selected 17 patients who received levocarnitine supplementation after starting lenvatinib therapy and 17 propensity-score-matched patients who did not receive levocarnitine. Sarcopenia was present in 76% of the patients at baseline. Changes in baseline SMI at 6 and 12 weeks of treatment were significantly suppressed in the group with levocarnitine supplementation compared with those without (p = 0.009 and p = 0.018, respectively). While there were no significant differences in serum free carnitine levels in cases without levocarnitine supplementation between baseline and after 6 weeks of treatment (p = 0.193), free carnitine levels were significantly higher after 6 weeks of treatment compared with baseline in cases with levocarnitine supplementation (p < 0.001). Baseline SMI and changes in baseline SMI after 6 weeks of treatment were significantly correlated with free carnitine levels (r = 0.359, p = 0.037; and r = 0.345, p = 0.045, respectively). Levocarnitine supplementation can suppress sarcopenia progression during lenvatinib therapy.

Biochemical and genetic characteristics of patients with primary carnitine deficiency identified through newborn screening

BackgroundPrimary carnitine deficiency (PCD) is an autosomal recessive disorder of carnitine transportation that leads to impaired fatty acid oxidation. Large-scale studies on newborn screening (NBS) for PCD are limited. This study aimed to investigate the biochemical and genetic characteristics of patients with PCD detected through NBS.ResultsA total of 548 247 newborns were screened for PCD between January 2014 and June 2021; 1714 newborns with low free carnitine (C0) levels were called back and 49 patients were diagnosed with PCD. The latest incidence rate in Quanzhou, China, was estimated to be 1 in 11 189 newborns. NBS results showed that the 49 patients had varying degrees of decreased C0 levels, whereas seven patients exhibited normal C0 levels during the recall review. All patients harbored biallelic pathogenic variants of the SLC22A5 gene. Nineteen distinct SLC22A5 variants were detected in these 49 patients, and most of the detected variants were clustered in exons 1, 4, and 7. The top eight variants had an allele frequency of 86.73%. The most common variant was c.760C > T (p.R254*) with an allele frequency of 31.63%, followed by c.51C > G (p.F17L) (17.35%) and c.1400C > G (p.S467C) (16.33%). The C0 level of patients with the N/N genotype was significantly lower than that of the M/M group. The C0 levels of patients with genotypes of R254*/R254* and R254*/F17L were far lower than those of patients with the R254*/S467C genotype.ConclusionsThis study presented more than 500,000 NBS data with the latest incidence of 1:11 189 in the Quanzhou area. The SLC22A5 variant spectrum in the selected southern Chinese population has been updated. Patients with null variants were associated with low C0 levels. Combining NBS with genetic testing is critical to improve screening efficiency because patients with PCD may have normal C0 levels during NBS and recall review.

The Effects of Streptozotocin-Induced Diabetes and Insulin Treatment on Carnitine Biosynthesis and Renal Excretion.

Carnitine insufficiency is reported in type 1 diabetes mellitus. To determine whether this is accompanied by defects in biosynthesis and/or renal uptake, liver and kidney were obtained from male Sprague-Dawley rats with streptozotocin-induced diabetes. Diabetic rats exhibited the metabolic consequences of type 1 diabetes, including hypoinsulinemia, hyperglycemia, and increased urine output. Systemic hypocarnitinemia, expressed as free carnitine levels, was evident in the plasma, liver, and kidney of diabetic rats. Compared to control rats, the low free carnitine in the plasma of diabetic rats was accompanied by decreased expression of γ-butyrobetaine hydroxylase in liver and kidney, suggesting impaired carnitine biosynthesis. Expression of organic cation transporter-2 in kidney was also reduced, indicating impaired renal reabsorption, and confirmed by the presence of elevated levels of free carnitine in the urine of diabetic rats. Insulin treatment of diabetic rats reversed the plasma hypocarnitinemia, increased the free carnitine content in both kidney and liver, and prevented urinary losses of free carnitine. This was associated with increased expression of γ-butyrobetaine hydroxylase and organic cation transporter-2. The results of our study indicate that type 1 diabetes induced with streptozotocin disrupts carnitine biosynthesis and renal uptake mechanisms, leading to carnitine insufficiency. These aberrations in carnitine homeostasis are prevented with daily insulin treatment.

Change in Anemia by Carnitine Supplementation in Patients Undergoing Peritoneal Dialysis: A Retrospective Observational Study.

Background: Carnitine supplementation improves various dialysis-related symptoms including erythropoietin-resistant anemia in patients who are undergoing hemodialysis. However, the utility of carnitine supplementation in patients who are undergoing peritoneal dialysis (PD) is not fully understood.Methods: Thirteen patients undergoing PD [mean age: 54.2 ± 14.8 years, males: 9/13 (69%)] administered oral carnitine supplementation (mean dose: 9.1 ± 3.3 mg/kg/day) for 4–6 months were retrospectively investigated. Changes in serum carnitine levels and other clinical variables including the erythropoietin resistance index (ERI) were analyzed after carnitine supplementation.Results: Carnitine supplementation increased serum total carnitine (48.5 ± 10.2 vs. 130.1 ± 37.2 μmol/L, P < 0.01), free carnitine (31.1 ± 8.3 vs. 83.1 ± 24.6 μmol/L, P < 0.01), and acyl carnitine (17.4 ± 2.8 vs. 46.9 ± 13.8, P < 0.01) levels. The acyl carnitine/free carnitine ratio was not affected (0.6 ± 0.1 vs. 0.6 ± 0.1, P = 0.75). Although the mean ERI was not affected by carnitine supplementation [13.7 ± 4.7 vs. 11.6 ± 3.4 IU/kg/(g/dL)/week, P = 0.28], the ERI change rate was significantly decreased (1.00 ± 0.00 vs. 0.87 ± 0.11, P < 0.01).Conclusion: Carnitine supplementation may improve erythropoietin resistance in patients who are undergoing PD.

Newborn screen metabolic panels reflect the impact of common disorders of pregnancy.

Hypertensive disorders of pregnancy and maternal diabetes profoundly affect fetal and newborn growth, yet disturbances in intermediate metabolism and relevant mediators of fetal growth alterations remain poorly defined. We sought to determine whether there are distinct newborn screen metabolic patterns among newborns affected by maternal hypertensive disorders or diabetes in utero. A retrospective observational study investigating distinct newborn screen metabolites in conjunction with data linked to birth and hospitalization records in the state of California between 2005 and 2010. A total of 41,333 maternal-infant dyads were included. Infants of diabetic mothers demonstrated associations with short-chain acylcarnitines and free carnitine. Infants born to mothers with preeclampsia with severe features and chronic hypertension with superimposed preeclampsia had alterations in acetylcarnitine, free carnitine, and ornithine levels. These results were further accentuated by size for gestational age designations. Infants of diabetic mothers demonstrate metabolic signs of incomplete beta oxidation and altered lipid metabolism. Infants of mothers with hypertensive disorders of pregnancy carry analyte signals that may reflect oxidative stress via altered nitric oxide signaling. The newborn screen analyte composition is influenced by the presence of these maternal conditions and is further associated with the newborn size designation at birth. Substantial differences in newborn screen analyte profiles were present based on the presence or absence of maternal diabetes or hypertensive disorder of pregnancy and this finding was further influenced by the newborn size designation at birth. The metabolic health of the newborn can be examined using the newborn screen and is heavily impacted by the condition of the mother during pregnancy. Utilizing the newborn screen to identify newborns affected by common conditions of pregnancy may help relate an infant's underlying biological disposition with their clinical phenotype allowing for greater risk stratification and intervention.

Carnitine deficiency in chronic obstructive lung disease: A study in a tertiary care centre

Chronic Obstructive Lung Disease (COPD) is a condition where there is poor airflow to the lungs and over a period of time this condition worsen, resulting in severe morbidity. L-carnitine (LC) is a soluble qaurtenary amine and is essential for the tissues and lung tone to function normally. This study was therefore find out the association of L-carnitine in patients with chronic Obstructive Pulmonary Disease. 75 patients who came to the Department of Pulmonology of either sex between 40 to 75 years with confirmed COPD were included into patients group and 75 healthy patients were included into the control group. Blood was collected for Fasting blood sugar, AST, ALP, ALT, Urea, Creatinine, Albumin, pre-albumin, iron , magnesium, sodium, phosphorous, calcium, Acylcarnitines, total and free carnitine levels. X-rays were taken and pulmonary function test was done for all the patients. The mean age of the patients in our study was 62.53 and 61.86 years among the patients and controls respectively. Among the controls the Ph and Fe levels were 3.1 ± 0.9mmol/L and 21.69 ± 3.19 mcg/dL respectively and among the patients the same levels were 2.6 ± 1.9mmol/L and 43.82 ± 8.22mcg/dL respectively. The albumin and the prealbumin in the patients were significantly lower in the patients with 21.81 ± 2.88 and 23.53 ±2.58 mg/dL and in controls they were 32.61 ±3.87 and 26.87 ± 1.93 mg/dL respectively. There was a considerable carnitine deficiencies in COPD patients when compared to the controls and since carnitine can be found in regular diet, people can be educated to have a proper intake of foods containing carnitine in their regular diet.

Possible correlation between increased serum free carnitine levels and increased skeletal muscle mass following HCV eradication by direct acting antivirals

We aimed to evaluate factors associated with changes in skeletal muscle mass in hepatitis C virus (HCV)-infected patients after treatment with direct-acting antivirals (DAAs). Consecutive HCV-infected patients after treatment with DAA were recruited into the study. Patients who achieved sustained virological response (SVR); and had complete clinical information, preserved serum samples at baseline and SVR48, and skeletal muscle mass evaluations based on the psoas muscle mass index (PMI) on computed tomography at baseline and ≥ 12 months were included. Altogether, 70.7% of patients (41/58) showed increased PMI after DAA therapy, and mean relative PMI was significantly higher after DAA therapy than at baseline. There were no significant associations between baseline clinical factors routinely examined in clinical practice and increased PMI. Among factors reported to be associated with skeletal muscle loss in patients with chronic liver disease, serum zinc levels and total and free carnitine levels increased significantly after DAA therapy and only changes in serum free carnitine levels were significantly associated with an increased PMI (r = 0305, P = 0.020). In conclusion, increased skeletal muscle mass after successful HCV eradication by DAAs was significantly associated with increased serum-free carnitine levels. l-carnitine supplementation may be beneficial in patients with low skeletal muscle mass after DAA.

Biochemical and molecular features of Chinese patients with glutaric acidemia type 1 detected through newborn screening

BackgroundGlutaric acidemia type 1 (GA1) is a treatable disorder affecting cerebral organic acid metabolism caused by a defective glutaryl-CoA dehydrogenase (GCDH) gene. GA1 diagnosis reports following newborn screening (NBS) are scarce in the Chinese population. This study aimed to assess the acylcarnitine profiles and genetic characteristics of patients with GA1 identified through NBS.Results From January 2014 to September 2020, 517,484 newborns were screened by tandem mass spectrometry, 102 newborns with elevated glutarylcarnitine (C5DC) levels were called back. Thirteen patients were diagnosed with GA1, including 11 neonatal GA1 and two maternal GA1 patients. The incidence of GA1 in the Quanzhou region was estimated at 1 in 47,044 newborns. The initial NBS results showed that all but one of the patients had moderate to markedly increased C5DC levels. Notably, one neonatal patient with low free carnitine (C0) level suggest primary carnitine deficiency (PCD) but was ultimately diagnosed as GA1. Nine neonatal GA1 patients underwent urinary organic acid analyses: eight had elevated GA and 3HGA levels, and one was reported to be within the normal range. Ten distinct GCDH variants were identified. Eight were previously reported, and two were newly identified. In silico prediction tools and protein modeling analyses suggested that the newly identified variants were potentially pathogenic. The most common variant was c.1244-2 A>C, which had an allelic frequency of 54.55% (12/22), followed by c.1261G>A (p.Ala421Thr) at 9.09% (2/22).ConclusionsNeonatal GA1 patients with increased C5DC levels can be identified through NBS. Maternal GA1 patients can also be detected using NBS due to the low C0 levels in their infants. Few neonatal GA1 patients may have atypical acylcarnitine profiles that are easy to miss during NBS; therefore, multigene panel testing should be performed in newborns with low C0 levels. This study indicates that the GCDH variant spectra were heterogeneous in this southern Chinese cohort.

Novel mutation in carnitine palmitoyltransferase 1A detected through newborn screening for a presymptomatic case in China: a case report

BackgroundCarnitine palmitoyltransferase 1A (CPT1A) deficiency is a rare mitochondrial fatty acid oxidation (FAO) disorder that results in hypoketotic hypoglycemia and hepatic encephalopathy. It is caused by mutation in CPT1A. To date, only two symptomatic cases of CPT1A deficiency have been reported in China.Case presentationA newborn male, without any disease-related clinical manifestations, was diagnosed with CPT1A deficiency through newborn screening. Increased free carnitine levels and a significantly increased C0/(C16 + C18) ratio were detected by tandem mass spectrometry, and subsequently, mutations in CPT1A were found by gene sequence analysis. The patient was advised a low-fat, high-protein diet and followed up regularly. During three-years of follow-up since, the patient showed normal growth velocity and developmental milestones. Whole-exome sequence identified two mutations, c.2201 T > C (p.F734S) and c.1318G > A (p.A440T), in the patient. The c.2201 T > C mutation, which has been reported previously, was inherited from his father, while the c.1318G > A, a novel mutation, was inherited from his mother. The amino acid residues encoded by original sequences are highly conserved across different species. These mutations slightly altered the three-dimensional structure of the protein, as analyzed by molecular modeling, suggesting that they may be pathogenic.ConclusionThis is the first case of CPT1A deficiency detected through newborn screening based on diagnostic levels of free carnitine, in China. Three years follow-up suggested that early diagnosis and diet management may improve the prognosis in CPT1A patient. In addition, we identified a novel mutation c.1318G > A in CPT1A,and a possible unique to Chinese lineage mutation c.2201 T > C. Our findings have expanded the gene spectrum of this rare condition and provided a basis for family genetic counseling and prenatal diagnosis.

Changes in carnitine levels through induction chemotherapy in head and neck cancer patients as a potential cause of therapy-related malaise

BackgroundCarnitine is related to malaise, and cisplatin is associated with decreased carnitine. The purpose of this study was to elucidate the effects of one course of induction chemotherapy (IC) for head and neck cancer on blood carnitine levels, focusing on free carnitine (FC).MethodsThis single-center prospective study investigated 20 patients diagnosed with primary head and neck cancer who underwent IC with cisplatin, docetaxel, and 5-fluorouracil. FC, acylcarnitine (AC), and total carnitine (TC) levels were measured before starting therapy and on Days 7 and 21 after starting IC. In addition, malaise was evaluated before and after therapy using a visual analog scale (VAS).ResultsAll subjects were men and the most common primary cancer site was the hypopharynx (9 patients). FC levels before starting therapy and on Days 7 and 21 were 47.7 ± 2.2 μM/mL, 56.7 ± 2.2 μM/mL, and 41.1 ± 1.9 μM/mL, respectively. Compared with the baseline before starting therapy, FC had significantly decreased on Day 21 (p = 0.007). AC levels before starting therapy and on Days 7 and 21 were 12.5 ± 1.2 μM/mL, 13.6 ± 1.4 μM/mL, and 10.7 ± 0.7 μM/mL, respectively. TC levels before starting therapy and on Days 7 and 21 were 60.2 ± 2.5 μM/mL, 70.2 ± 3.3 μM/mL, and 51.7 ± 2.3 μM/mL, respectively. No significant differences in AC, TC or VAS were seen before the start of therapy and on Day 21.ConclusionsAfter IC, a latent decrease in FC occurred without any absolute deficiency or subjective malaise.

Newborn Screening and Genetic Analysis Identify Six Novel Genetic Variants for Primary Carnitine Deficiency in Ningbo Area, China.

Primary carnitine deficiency (PCD) is an autosomal recessive disorder that could result in sudden death. It is caused by a defect in the carnitine transporter encoded by SLC22A5 (Solute Carrier Family 22 Member 5, MIM:603377). Currently, a number of variants in SLC22A5 have been identified, however, the PCD prevalence and its variants in Ningbo area are unclear. In this study, we screened 265,524 newborns by using tandem mass spectrometry. Variants in SLC22A5 were further detected by next-generation sequencing in individuals with abnormal free carnitine levels (C0). We identified 53 newborns with abnormal C0 levels and 26 with variants in SLC22A5. Among them, 16 with compound heterozygous or homozygous variants in SLC22A5 were diagnosed with PCD, suggesting the PCD birth prevalence in Ningbo city was 1/16,595. Moreover, the C0 level was significantly (P = 0.013) higher in PCD patients than in those with one variant. Besides, the c.1400C > G (p. S467C) and c.51C > G (p. F17L) variants were the most frequent and six novel variants are all predicted to be damaging. This study reports the largest PCD patients in Ningbo area by newborn screening and expands the variant spectrum of SLC22A5. Our findings demonstrate the clinical value of combining NBS program results with DNA analysis for the diagnosis of PCD.

Factors associated with blood carnitine levels in adult epilepsy patients with chronic valproic acid therapy

AimsValproic acid (VPA) is a widely used antiepileptic drug for the treatment of epilepsy, seizures, and bipolar and psychiatric disorders. A deficiency of carnitine, a compound involved in energy production, is associated with chronic VPA use. However, the clinical factors affecting blood carnitine levels and their pathophysiology remain unclear. Hence, we aimed to identify the factors that correlated with serum carnitine levels in epilepsy patients receiving chronic VPA therapy. MethodsThis observational study included 138 epilepsy patients receiving chronic VPA therapy. Serum total and free carnitine levels, routine blood tests and drug concentrations were assessed. The correlation between carnitine levels and other factors were calculated using Spearman's rank correlation coefficients, and a principal component analysis (PCA) and a multiple linear regression analysis were performed. ResultsOverall, serum free carnitine levels showed significant negative correlations with epilepsy duration, VPA treatment duration, daily VPA dose, and blood VPA concentration. A significant positive correlation was observed with erythrocyte count, hemoglobin levels, and creatinine levels. Of the 138 patients, 21 (15.2 %) with serum free carnitine levels of <20 μmol/L had significantly longer disease duration, a higher daily VPA dose, and lower blood clobazam concentrations. In the 48 VPA monotherapy patients, serum free carnitine levels showed a significant negative correlation with disease duration and duration of VPA therapy. Furthermore, in the 2.1 % patients receiving VPA monotherapy, serum free carnitine levels were <20 μmol/L. PCA resulted in seven factor solution (eigenvalue >1; 71.67 % explained variance). Component 1 clearly revealed the maximal loading for serum free carnitine level (.792) and the most negative loading for disease duration of epilepsy (−.595). A linear regression analysis revealed that the duration of epilepsy, serum creatinine level, and daily dose of VPA were significant (p < .01) factors that affected serum free carnitine levels. ConclusionsThe effects of combination therapy with VPA and other anti-epileptic drug(s) on carnitine levels are higher than that of VPA monotherapy. Additionally, epilepsy duration may affect serum free carnitine level.

Effect of L-carnitine supplementation on lipid profile and apolipoproteins in children on hemodialysis: a randomized placebo-controlled clinical trial

Cardiovascular disease (CVD) is the leading cause of death in children with chronic kidney disease (CKD) and accounts for 40% of all deaths among pediatric patients with stage5 chronic kidney disease (CKD5). Dyslipidemia is common in children with CKD and is considered one of the major causes of CVD in these patients. As carnitine plays a key role in lipid metabolism and because plasma levels are reduced in hemodialysis patients, the aim of this study was to determine the effects of L-carnitine supplementation on serum lipid profiles, apolipoproteins, and free carnitine (FC) levels. A total of 30 children on hemodialysis (6-18 years) were enrolled and 24 completed the study. Twelve patients received 50 mg/kg/day L-carnitine, while the other 12 patients received placebo for 10 weeks. Serum FC, total cholesterol (TC), LDL-C, HDL-C, TG, Apolipoprotein B (ApoB), and Apolipoprotein A1 (ApoA1) were determined at the baseline and after the intervention. One-way repeated measures analysis was used to evaluate the effects of L-carnitine supplementation. Oral L-carnitine supplementation led to decreased ApoB levels and ApoB/ApoA1 ratio, but these changes were not significant compared to placebo. Meanwhile, L-carnitine supplementation significantly reduced serum LDL-C and TC and increased serum FC compared to placebo. No significant changes were observed in serum TG and HDL-C levels. Given the significant reduction in LDL-C and TC levels, L-carnitine supplementation had positive effects on improving hyperlipidemia in children receiving hemodialysis. For more decisive results, studies with longer duration of L-carnitine therapy on children receiving hemodialysis with significant dyslipidemia are recommended. We registered the present trial in the Iranian Registry of Clinical Trials website (available at: http://www.irct.ir , identifier: IRCT20170202032367N2).

Increased detection of primary carnitine deficiency through second-tier newborn genetic screening

BackgroundNewborn screening for primary carnitine deficiency (NBS) is commonly implemented worldwide; however, it has poor sensitivity. This study aimed to evaluate the feasibility of improving screening by including a second-tier genetic assay.ResultsAn Agena iPLEX assay was developed to identify 17 common SLC22A5 mutations in Chinese populations and was applied in NBS as a second-tier screening. From January 2017 to December 2018, 204,777 newborns were screened for PCD using tandem mass spectrometry. A total of 316 (0.15%) residual NBS-positive specimens with low free carnitine (C0) levels were subjected to this second-tier screening. The screening identified 20 screen-positive newborns who harboured biallelic mutations in theSLC22A5 gene, 99 carriers with one mutation, and 197 screen-negative newborns with no mutations. Among the 99 carriers, four newborns were found to have a second disease-causing SLC22A5mutation by further genetic analysis. Among the 197 screen-negatives were four newborns with persistently low C0 levels, and further genetic analysis revealed that one newborn had two novel SLC22A5 pathogenic variants. In total, 25 newborns were diagnosed with PCD, for a positive predictive value of 7.91% (25/316). Based on these data, we estimate the incidence of PCD in Quanzhou is estimated to be 1:8191.Thirteen distinct SLC22A5 variants were identified, and the most common was c.760C > T, with an allelic frequency of 32% (16/50), followed by c.1400C > G (7/50, 14%), and c.51C > G (7/50, 14%).ConclusionData from this study revealed that 24% (6/25) of PCD cases would have been missed by conventional NBS. This high-throughput iPLEX assay is a powerful tool for PCD genotyping. The addition of this second-tier genetic screening to the current NBS program could identify missed PCD cases, thereby increasing PCD detection. However, further studies are needed to optimise the workflow of the new screening algorithm and to evaluate the cost-effectiveness of this screening approach.

Carnitine supplementation prevents carnitine deficiency caused by pivalate-conjugated antibiotics in patients with epilepsy prescribed valproate

We measured carnitine levels before and after pivalate-conjugated antibiotic (PCA) use in six patients with epilepsy who were prescribed valproate (VPA). Three of the patients were on carnitine supplementation when PCA use started. Serum FC levels were within the normal range (37.2–49.0 μmol/L) in all six patients before PCA use. After PCA use, the serum free carnitine (FC) levels remained within the normal range (48.0–68.2 μmol/L) in all three patients on carnitine supplementation, but were below the normal range (18.7–30.8 μmol/L) in the three patients not on carnitine supplementation. No remarkable changes in serum VPA levels, platelet count, amylase or ammonia level was evident in any patients in relation to PCA use. Carnitine deficiency due to PCA use was prevented by carnitine supplementation in patients with epilepsy who were taking VPA. Carnitine supplementation can support patients at risk of carnitine deficiency.

Effectiveness of monitoring free carnitine levels for L-carnitine supplementation in hemodialysis patients to maintain carnitine sufficiency and nutritional factors.

We investigated the effectiveness of monitoring serum carnitine levels in hemodialysis patients receiving L-carnitine supplementation. One-hundred forty-five hemodialysis patients were divided into three groups. Group 1 consisted of patients (n= 30) who had been receiving supplementation before this study and then discontinued at the beginning. The remaining patients were divided into Group 2 (n= 13) and Group 3 (n= 102) based on their baseline free carnitine (FC) level, <20 or ≥ 20 μmol/L. Group 2 was started on supplementation, and Groups 1 and 3 were observed without any intervention for the first 6 months. FC was measured every 6 months in all three groups up to 18 months. All patients in whom FC was less than 20 μmol/L at 6 and 12 months were prescribed supplementation. After the first 6 months, the mean ± SD of FC changed from 262.5 ± 87.5 μmol/L at baseline to 70.8 ± 33.6 μmol/L (P< 0.001) in Group 1, from 17.4 ± 1.9 to 193.9 ± 43.3 μmol/L (P< 0.001) in Group 2, and from 49.2 ± 24.6 to 44.2 ± 19.8 μmol/L (P< 0.05) in Group 3. The acyl/free carnitine changed from 0.62 to 0.59 in Group 1 (P= 0.287), from 0.76 to 0.66 in Group 2 (P= 0.054) and from 0.57 to 0.60 in Group 3 (P< 0.05). Of the 145 patients, 126 continued follow-up for the full 18 months. FC remained in the normal range (36-74 μmol/L) within the 95% CI. FC was considered a strong predictor of carnitine deficiency after 6 months (AUC: 0.9146, cut-off value: 33.8 μmol/L). FC monitoring is essential for appropriate carnitine supplementation in hemodialysis patients.

Evaluation of micronutrient levels in children and adolescents with obesity and their correlation with the components of metabolic syndrome.

Obesity is a significant public health problem worldwide. Vitamin deficiencies, developing due to monotype nutrition, are more likely to be observed in patients than healthy children. The present study evaluates vitamin and micronutrient levels in children and adolescents with obesity and metabolic syndrome compared to healthy controls. The study included 73 patients with obesity, 64 patients with metabolic syndrome and 71 healthy children (control group) aged 10 to 16 years. Physical examinations were performed, and waist circumference and systolic blood pressure measurements were recorded. Fasting blood glucose, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, insulin, vitamin A, vitamin E, vitamin B1, vitamin B2, vitamin B6, vitamin B12, folic acid and free carnitine levels were analyzed. The homeostatic model of assessment-insulin resistance (HOMA-IR) index was calculated and recorded. The mean age of all patients was 11.9±2.6 years. The serum insulin level and HOMA-IR index were found to be significantly higher in the obesity and metabolic syndrome groups. No significant difference was found between the groups in terms of vitamin A, vitamin B6 and free carnitine levels. Significantly decreased vitamin E, vitamin B2, vitamin B12 and folic acid and increased vitamin B1 levels were observed in the obesity and metabolic syndrome groups. Compared to healthy children, children with obesity and metabolic syndrome may have varying degrees of micronutrient and vitamin deficiency due to poor and unbalanced eating habits. These deficiencies should also be considered in the treatment and follow-up of obesity and metabolic syndrome.