Effects of intravenous l-carnitine on myocardial fatty acid imaging in hemodialysis patients: responders or non-responders to l-carnitine

Association of Abnormal Serum L-Carnitine Levels with Idiopathic Changes in Left Ventricular Geometry in Pediatric and Adolescent Patients

Background

There is no compelling evidence to prove an association between serum free L-carnitine levels and changes in left ventricular (LV) geometry. The present study aimed to evaluate a possible association between these parameters.

Methods

In a cross-sectional study, 504 outpatients were randomly selected among those registered at Sanandaj Pediatric Heart Clinic (Sanandaj, Iran) during 2014-2020. The patients aged one to 25 years and were presented with cardiac complaints. The serum L-carnitine levels of all patients were evaluated and associated with changes in LV geometry measured by echocardiography. The association was assessed using the Chi squared test, Fisher's exact test, and one-way ANOVA with post hoc Tukey test. Data were analyzed using SPSS software (version 22.0). P≤0.05 was considered statistically significant.

Results

The mean serum L-carnitine levels in the normal, low, and high serum groups were 52.69, 14.16, and 178.67 nmol/dL, respectively. There was a significant statistical association between abnormal serum levels of free L-carnitine and changes in LV geometry (P<0.001).

Conclusion

Our findings are indicative of an association between abnormal serum L-carnitine levels and changes in LV geometry in pediatric and adolescent patients.

The role of carnitine in maintenance dialysis therapy

Carnitine metabolism and homeostasis is significantly altered in patients receiving maintenance dialysis. Current literature in the adult and pediatric dialysis populations suggest a high prevalence of carnitine deficiency, which may lead to erythropoietin-resistant anemia, cardiomyopathy, and muscle weakness. However, the results of pediatric dialysis studies are limited and have not provided the evidence necessary to support strong recommendations or guidelines pertaining to carnitine management. The characteristics and function of carnitine, the definition and consequences of deficiency, a brief overview of recent adult studies, and current studies on carnitine supplementation in pediatric hemodialysis (HD) and peritoneal dialysis (PD) populations are discussed in this review.

Serum carnitine concentration and the acyl to free carnitine ratio in nondialysis chronic kidney disease and hemodialysis patients

Mechanisms of impaired fatty acid metabolism may not be the same in nondialysis and hemodialysis patients. Correlations between the serum-free carnitine concentration (FC), acylcarnitine concentration (AC), acyl to free carnitine ratio (AC/FC), and estimated glomerular filtration rate (eGFR) in the nondialysis population and the duration of hemodialysis in hemodialysis patients were investigated. As the eGFR decreased, the FC and AC increased, and as the duration of hemodialysis became longer, the FC and AC decreased. The AC/FC increased consistently as the eGFR decreased and the duration of hemodialysis increased. As an exception, the AC/FC decreased in the patients with a hemodialysis duration less than 90 days, which was not explained by carnitine removal by hemodialysis. In nondialysis patients, a functional, rather than an absolute, carnitine deficiency is a main cause of impaired fatty acid metabolism. Long-term hemodialysis exacerbates absolute carnitine deficiency, whereas hemodialysis treatment may improve impaired fatty acid metabolism.

QT Prolongation in Dialysis Patients: An Epidemiological Study with a Focus on Malnutrition

BACKGROUND/AIMS

QT prolongation is a known risk factor for ventricular fibrillation and ventricular tachycardia. Therefore, more refined management is necessary to reduce sudden cardiac death secondary to such arrhythmias.

METHODS

Electrocardiographic findings were reviewed in 224 patients, and the associations of QT prolongation with various clinical parameters were examined, including the nutritional state. Correlations were also examined between QT prolongation and body composition measurements determined by multifrequency bioelectrical impedance analysis.

RESULTS

Prolongation of the corrected QT (QTc) interval over 0.44 s was seen in 140 patients (62.5%). QT prolongation was independent of age and dialysis therapy duration and was more frequent in diabetics (70.1%) than in nondiabetics (54.2%, p = 0.014) and more frequent in women (78.8%) than in men (53.5%, p < 0.001). Serum levels of albumin (p < 0.001) and Cr (p < 0.001) and the Geriatric Nutritional Risk Index (GNRI, p < 0.001) were negatively correlated with QTc interval; no significant correlation was noted with total protein, urea nitrogen, or uric acid. Negative correlations with QTc interval were found for BMI(p < 0.01), percent total body water (%TBW; p < 0.05), and percent intracellular water (%ICW; p < 0.01) but not with the percent extracellular water/TBW ratio or edema ratio. The longer the QTc interval, the lower the fat-free mass (FFM; p < 0.01) and muscle mass (MM; p < 0.01), but there was no significant correlation with percent fat.

CONCLUSION

These results suggest that QT prolongation is a common complication and is more frequent in women and diabetic patients. The decreases in serum albumin and Cr levels, GNRI, BMI, %TBW, %ICW, FFM, and MM together coincided with malnutrition and thus suggest a close relationship of QT prolongation with malnutrition. Management of QT prolongation may be achieved better in the future by understanding these biochemical and biophysical changes, particularly those regarding malnutrition.

L-carnitine Improved the Cardiac Function via the Effect on Myocardial Fatty Acid Metabolism in a Hemodialysis Patient

Patients on hemodialysis often have carnitine deficiency. We herein report a woman who experienced the dramatic improvement of cardiac dysfunction after intravenous L-carnitine administration. We also investigated the myocardial fatty acid metabolism using ¹²³I-labeled β-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT) before and after L-carnitine therapy, and the impaired metabolism was ameliorated. Taken together, these findings indicate that L-carnitine therapy improved cardiac dysfunction via the amelioration of the abnormal myocardial fatty acid metabolism, at least in part.

Solving manufacturing problems for L-carnitine-L-tartrate to improve the likelihood of successful product scale-up

L-carnitine-L-tartrate, a non-essential amino acid, is hygroscopic. This causes a problem in tablet production due to pronounced adhesion of tablets to punches. A 33 full factorial design was adopted to suggest a tablet formulation. Three adsorbents were suggested (Aerosil 200, Aerosil R972, talc) to reduce stickiness at three concentrations (1, 3 and 5 %), and three fillers (mannitol, Avicel PH 101, Dibasic calcium phosphate) were chosen to prepare 27 formulations. Micromeritic properties of formulations were studied, and tablets were prepared by wet granulation. Absence of picking, sticking or capping, recording of sufficient hardness, acceptable friability and tablet ejection force indicated formulation success. The resulting formulation prepared using Avicel PH 101 and 1 % Aerosil 200 was submitted to further investigation in order to choose the most suitable compression conditions using a 33 full factorial design. Variables included compression force, tableting rate and magnesium stearate (lubricant) concentration. The formulation prepared at compression force of 25 kN, using 2 % magnesium stearate, at a production rate of 30 tablets/ minute, was found to be the most appropriate scale up candidate.

Efficacy and Safety of L-Carnitine Treatment for Chronic Heart Failure: A Meta-Analysis of Randomized Controlled Trials

Background. Whether additional benefit can be achieved with the use of L-carnitine (L-C) in patients with chronic heart failure (CHF) remains controversial. We therefore performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the effects of L-C treatment in CHF patients. Methods. Pubmed, Ovid Embase, Web of Science, and Cochrane Library databases, Chinese National Knowledge Infrastructure (CNKI) database, Wanfang database, Chinese Biomedical (CBM) database, and Chinese Science and Technology Periodicals database (VIP) until September 30, 2016, were identified. Studies that met the inclusion criteria were systematically evaluated by two reviewers independently. Results. 17 RCTs with 1625 CHF patients were included in this analysis. L-C treatment in CHF was associated with considerable improvement in overall efficacy (OR = 3.47, P < 0.01), left ventricular ejection fraction (LVEF) (WMD: 4.14%, P = 0.01), strike volume (SV) (WMD: 8.21 ml, P = 0.01), cardiac output (CO) (WMD: 0.88 L/min, P < 0.01), and E/A (WMD: 0.23, P < 0.01). Moreover, treatment with L-C also resulted in significant decrease in serum levels of BNP (WMD: −124.60 pg/ml, P = 0.01), serum levels of NT-proBNP (WMD: −510.36 pg/ml, P < 0.01), LVESD (WMD: −4.06 mm, P < 0.01), LVEDD (WMD: −4.79 mm, P < 0.01), and LVESV (WMD: −20.16 ml, 95% CI: −35.65 to −4.67, P < 0.01). However, there were no significant differences in all-cause mortality, 6-minute walk, and adverse events between L-C and control groups. Conclusions. L-C treatment is effective for CHF patients in improving clinical symptoms and cardiac functions, decreasing serum levels of BNP and NT-proBNP. And it has a good tolerance.