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1.
The effect of L-carnitine supplementation on insulin resistance, sex hormone-binding globulin and lipid profile in overweight/obese women with polycystic ovary syndrome: a randomized clinical trial.
Sangouni, AA, Pakravanfar, F, Ghadiri-Anari, A, Nadjarzadeh, A, Fallahzadeh, H, Hosseinzadeh, M
European journal of nutrition. 2022;(3):1199-1207
Abstract
PURPOSE Polycystic ovary syndrome (PCOS) is a common endocrine disorder among reproductive-age women. Insulin resistance and dyslipidemia are linked to PCOS. L-Carnitine supplementation as a management strategy for women with PCOS has been proposed. The effect of L-carnitine supplementation on insulin resistance, sex hormone-binding globulin (SHBG) and lipid profile in overweight/obese women with PCOS was investigated. METHODS This randomized, double-blind, controlled clinical trial, was conducted on 62overweight/obese women with PCOS. Participants were randomly assigned into two groups to receive 1000 mg/day L-carnitine or placebo (1000 mg starch) for 12 weeks. RESULTS L-Carnitine supplementation compared to the placebo showed a significant improvement in insulin [- 0.7 (- 7.3 to 4.0) vs. 0.7 (- 3.0 to 5.2); P = 0.001], homeostatic model assessment for insulin resistance [- 0.4 (- 1.7 to 1.1) vs. 0.0 (- 0.7 to 1.3); P = 0.002], quantitative insulin sensitivity check index (+ 0.01 ± 0.02 vs. - 0.01 ± 0.01; P = 0.02) and a non-significant change toward improvement in SHBG (+ 11.5 ± 40.2 vs. - 3.2 ± 40.2; P = 0.2). However, there was no significant differences between the two groups in serum levels of fasting plasma glucose, total cholesterol, triglyceride, low density lipoprotein-cholesterol and high density lipoprotein cholesterol (P > 0.05). CONCLUSION 12-week L-carnitine supplementation in overweight or obese women with PCOS ameliorate insulin resistance, but has no effect on SHBG and lipid profile. Studies with higher dosages and duration of L-carnitine intake are required. The trial was registered on 30 December 2019 at Iranian Registry of Clinical Trials IRCT20191016045131N1. TRIAL REGISTRATION Registered on 30th December 2019 at Iranian Registry of Clinical Trials (IRCT20191016045131N1).
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2.
The Effect of L-Carnitine on Mortality Rate in Septic Patients: A Systematic Review and Meta-Analysis on Randomized Clinical Trials.
Abdollahi, H, Abdolahi, M, Sedighiyan, M, Jafarieh, A
Endocrine, metabolic & immune disorders drug targets. 2021;(4):673-681
Abstract
BACKGROUND Recent clinical trial studies have reported that L-carnitine supplementation can reduce the mortality rate in patients with sepsis, but there are no definitive results in this context. The current systematic review and meta-analysis aimed to evaluate the effect of L-carnitine supplementation on 28-day and one-year mortality in septic patients. METHODS A systematic search conducted on Pubmed, Scopus and Cochrane Library databases up to June 2019 without any language restriction. The publications were reviewed based on the Cochrane handbook and preferred reporting items for systematic reviews and meta-analyses (PRISMA). To compare the effects of L-carnitine with placebo, Risk Ratio (RR) with 95% confidence intervals (CI) were pooled according to the random effects model. RESULTS Across five enrolled clinical trials, we found that L-carnitine supplementation reduce one-year mortality in septic patients with SOFA> 12 (RR: 0.68; 95% CI: 0.49 to 0.96; P= 0.03) but had no significant effect on reducing 28-day mortality ((RR: 0.93; 95% CI: 0.68 to 1.28; P= 0.65) compared to placebo. Finally, we observed that based on current trials, L-carnitine supplementation may not have clinically a significant effect on mortality rate. CONCLUSION L-carnitine patients with higher SOFA score can reduce the mortality rate. However, the number of trials, study duration and using a dosage of L-carnitine are limited in this context and further large prospective trials are required to clarify the effect of L-carnitine on mortality rate in septic patients.
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3.
Evaluation of Plasma Free Amino Acid and Carnitine Levels in Patients with Cesarean Scar Pregnancy.
Tammo, O, Uyanikoglu, H, Koyuncu, İ
Combinatorial chemistry & high throughput screening. 2021;(9):1436-1445
Abstract
AIM AND OBJECTIVE This study aimed to explore the plasma free amino acid (FAA) and carnitine levels in pregnant women with cesarean scar pregnancy (CSP), and to compare them with those of healthy pregnant women. MATERIALS AND METHODS This prospective and randomized controlled study was conducted in patients admitted to Harran University Medical Faculty Hospital Obstetrics Clinic between January 2018 and January 2019. A total of 60 patients were included in the study, and the patients were divided into two groups: the CSP group (n = 30) and the healthy pregnant group as the control group (n = 30). The blood samples were taken from the participants between 7 - 12 weeks of gestation. Twenty-seven carnitines and their esters and 14 FAAs were analysed by liquid chromatography - mass spectrometry (LC-MS/MS). RESULTS The mean plasma concentrations of some carnitines, including C2, C5, C5-OH, C5-DC, C6, C8-1, C12, C14, C14-1, C14-2, C16, C16-1, C18, and C18-1 were significantly higher in the CSP group than in the control group. However, other carnitines, including C0, C3, C4, C4-DC, C5- 1, C6-DC, C8, C8-DC, C10, C10-1, C18-1-OH, and C18-2, were similar in both groups. The plasma levels of some FAAs, including Methyl Glutaryl, Leu, Met, Phe, Arg, Orn, and Glu values, were significantly higher in the CSP group than in the control group. However, there was no statistical significance in other FAA levels, including Val, Asa, Tyr, Asp, Ala, Cit, and Gly between the two groups. Additionally, Pearson's correlation analysis showed that there were significantly positive correlations between many FAA and carnitine values. CONCLUSION Since several plasma carnitines and FAA levels were higher in the CSP group than in the control group, we think that scar pregnancy increases the metabolic need for myometrial invasion. Also, we think that these results may be useful in clinical practice for CSP diagnosis.
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4.
Effect of L-carnitine supplementation on renal anemia in patients on hemodialysis: a meta-analysis.
Zhu, Y, Xue, C, Ou, J, Xie, Z, Deng, J
International urology and nephrology. 2021;(10):2149-2158
Abstract
BACKGROUND L-carnitine is an amino acid derivative that is thought to be helpful for treating renal anemia in hemodialysis patients. However, the mechanism remains to be fully elucidated. METHODS A literature search was performed on PubMed, Embase, and Cochrane Central Register of Controlled Trials to identify randomized controlled trials (RCTs) and conduct a meta-analysis for investigating the effect of L-carnitine in the treatment of renal anemia in participants receiving hemodialysis. RESULTS A total of 18 eligible trials with 1090 participants were included in this study. L-carnitine can significantly increase plasma free L-carnitine levels (mean difference [MD]: 140.53, 95% confidence interval [CI] 102.22-178.85; P < 0.00001), decrease the erythropoietin responsiveness index (ERI; MD: -2.72, 95% CI -3.20 to -2.24; P < 0.00001) and the required erythropoiesis-stimulating agent (ESA) doses (MD: -1.70, 95% CI -2.04 to -1.36; P < 0.00001). However, the use of L-carnitine was not associated with a higher hemoglobin level (MD: 0.18, 95% CI -0.20 to 0.55; P = 0.35) and hematocrit level (MD: 1.07, 95% CI -0.73 to 2.87; P = 0.24). In subgroup analyses, the effects of L-carnitine supplementation on renal anemia in patients on hemodialysis were independent of the treatment duration and intervention routes. CONCLUSION The present meta-analysis indicated that L-carnitine therapy significantly increased plasma L-carnitine concentrations, improved the response to ESA, decreased the required ESA doses in patients receiving hemodialysis, and maintained hemoglobin and hematocrit levels. L-carnitine supplementation should be supported in hemodialysis patients. However, the relationship between L-carnitine treatment and long-term outcomes is still unclear. Further high-quality RCTs are needed to verify our findings.
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5.
Possible Neuroprotective Effects of l-Carnitine on White-Matter Microstructural Damage and Cognitive Decline in Hemodialysis Patients.
Ueno, Y, Saito, A, Nakata, J, Kamagata, K, Taniguchi, D, Motoi, Y, Io, H, Andica, C, Shindo, A, Shiina, K, et al
Nutrients. 2021;(4)
Abstract
Although l-carnitine alleviated white-matter lesions in an experimental study, the treatment effects of l-carnitine on white-matter microstructural damage and cognitive decline in hemodialysis patients are unknown. Using novel diffusion magnetic resonance imaging (dMRI) techniques, white-matter microstructural changes together with cognitive decline in hemodialysis patients and the effects of l-carnitine on such disorders were investigated. Fourteen hemodialysis patients underwent dMRI and laboratory and neuropsychological tests, which were compared across seven patients each in two groups according to duration of l-carnitine treatment: (1) no or short-term l-carnitine treatment (NSTLC), and (2) long-term l-carnitine treatment (LTLC). Ten age- and sex-matched controls were enrolled. Compared to controls, microstructural disorders of white matter were widely detected on dMRI of patients. An autopsy study of one patient in the NSTLC group showed rarefaction of myelinated fibers in white matter. With LTLC, microstructural damage on dMRI was alleviated along with lower levels of high-sensitivity C-reactive protein and substantial increases in carnitine levels. The LTLC group showed better achievement on trail making test A, which was correlated with amelioration of disorders in some white-matter tracts. Novel dMRI tractography detected abnormalities of white-matter tracts after hemodialysis. Long-term treatment with l-carnitine might alleviate white-matter microstructural damage and cognitive impairment in hemodialysis patients.
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6.
L-Carnitine Tartrate Supplementation for 5 Weeks Improves Exercise Recovery in Men and Women: A Randomized, Double-Blind, Placebo-Controlled Trial.
Stefan, M, Sharp, M, Gheith, R, Lowery, R, Ottinger, C, Wilson, J, Durkee, S, Bellamine, A
Nutrients. 2021;(10)
Abstract
UNLABELLED L-carnitine tartrate has been shown to improve relatively short-term recovery among athletes. However, there is a lack of research on the longer-term effects in the general population. OBJECTIVE The primary objectives of this randomized double-blind, placebo-controlled trial were to evaluate the effects of daily L-carnitine tartrate supplementation for 5 weeks on recovery and fatigue. METHOD In this study, eighty participants, 21- to 65-years-old, were recruited. Participants were split into two groups of forty participants each, a placebo, and a L-carnitine Tartrate group. Seventy-three participants completed a maintenance exercise training program that culminated in a high-volume exercise challenge. RESULTS Compared to placebo, L-carnitine tartrate supplementation was able to improve perceived recovery and soreness (p = 0.021), and lower serum creatine kinase (p = 0.016). In addition, L-carnitine tartrate supplementation was able to blunt declines in strength and power compared to placebo following an exercise challenge. Two sub-analyses indicated that these results were independent of gender and age. Interestingly, serum superoxide dismutase levels increased significantly among those supplementing with L-carnitine tartrate. CONCLUSIONS These findings agree with previous observations among healthy adult subjects and demonstrate that L-carnitine tartrate supplementation beyond 35 days is beneficial for improving recovery and reducing fatigue following exercise across gender and age.
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7.
L-Carnitine's Effect on the Biomarkers of Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Choi, M, Park, S, Lee, M
Nutrients. 2020;(9)
Abstract
A systematic review and meta-analysis of randomized controlled trials (RCTs) was carried out to assess L-carnitine supplements' influence on the biomarkers of metabolic syndrome (MetSyn). PubMed, EMBASE, Cochrane library, and CINAHL were used to collect RCT studies published prior to February 2020. RCT studies were included if they had at least one of the following biomarker outcome measurements: waist circumference (WC), blood pressure (BP), fasting blood sugar (FBS), triglyceride (TG), or high density lipoprotein-cholesterol (HDLc). Nine of twenty studies with adequate methodological quality were included in this meta-analysis. The dose of L-carnitine supplementation administered varied between 0.75 and 3 g/day for durations of 8-24 weeks. L-carnitine supplementation significantly reduced WC and systolic BP (SBP), with no significant effects on FBS, TG, and HDLc. We found that L-carnitine supplementation at a dose of more than 1 g/d significantly reduced FBS and TG and increased HDLc. In conclusion, L-carnitine supplementation is correlated with a significant reduction of WC and BP. A dose of 1-3 g/d could improve the biomarkers of MetSyn by reducing FBS and TG and increasing HDLc.
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8.
The significant role of carnitine and fatty acids during pregnancy, lactation and perinatal period. Nutritional support in specific groups of pregnant women.
Manta-Vogli, PD, Schulpis, KH, Dotsikas, Y, Loukas, YL
Clinical nutrition (Edinburgh, Scotland). 2020;(8):2337-2346
Abstract
BACKGROUND & AIMS Pregnancy is characterized by a complexity of metabolic processes that may impact fetal health and development. Women's nutrition during pregnancy and lactation is considered important for both mother and infant. This review aims to investigate the significant role of fatty acids and carnitine during pregnancy and lactation in specific groups of pregnant and lactating women. METHODS The literature was reviewed using relevant data bases (e.g. Pubmed, Scopus, Science Direct) and relevant articles were selected to provide information and data for the text and associated Tables. RESULTS Dynamic features especially of plasma carnitine profile during pregnancy and lactation, indicate an extraordinarily active participation of carnitine in the intermediary metabolism both in pregnant woman and in neonate and may also have implications for health and disease later in life. Maternal diets rich in trans and saturated fatty acids can lead to impairments in the metabolism and development of the offspring, whereas the consumption of long chain-polyunsaturated fatty acids during pregnancy plays a beneficial physiologic and metabolic role in the health of offspring. CONCLUSIONS Pregnant women who are underweight, overweight or obese, with gestational diabetes mellitus or diabetes mellitus and those who choose vegan/vegetarian diets or are coming from socially disadvantaged areas, should be nutritionally supported to achieve a higher quality diet during pregnancy and/or lactation.
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9.
The effect of l-carnitine supplementation on lipid profile and glycaemic control in adults with cardiovascular risk factors: A systematic review and meta-analysis of randomized controlled clinical trials.
Asadi, M, Rahimlou, M, Shishehbor, F, Mansoori, A
Clinical nutrition (Edinburgh, Scotland). 2020;(1):110-122
Abstract
BACKGROUND & AIMS Several randomized clinical trials (RCTs) have investigated the effect of l-carnitine supplementation on lipid profile and glycaemic control in adults with cardiovascular risk factors; however, the results were conflicting. Therefore, a meta-analysis was performed to assess the effect of l-carnitine on lipid profile and glycaemic control in adults with cardiovascular risk factors. METHODS We searched PubMed, Scopus, Cochrane Databases, Google Scholar, ProQuest, Web of Science and Embase for randomized, placebo-controlled human trials that investigated the effect of l-carnitine supplementation on lipid profile and glycaemic control up to April 2017. From the eligible trials, 24 articles were selected for the meta-analysis. The meta-analysis was performed in a random-effects model. Heterogeneity was determined by I2 statistics and Cochrane Q test. RESULTS The result showed significant effect of l-carnitine on TC (WMD: -13.73 [95% CI: -22.28, -5.17] mg/dL; P < 0.001), LDL-C (WMD = - 7.70 [95% CI: - 11.80, -3.61]mg/dL; p < 0.001), HDL-C (WMD = 0.82 [95% CI: 0.44, 1.21] mg/dL; P > 0.001), Lp(a) (WMD = - 7.13 [95% CI: -9.82,- 4.43]mg/dL; P < 0.001), FPG (WMD = -6.25 [95% CI: -10.35, -2.16] mg/dL; P < 0.001), HbA1C (WMD (%) = - 0.35 [95% CI: -0.65,- 0.05]; p = 0.02) and HOMA-IR (WMD (%) = - 0.94 [95% CI: -1.89, -0.00]; P = 0.05). No effect of l-carnitine was detected in TG, Apo A-I and Apo B 100 on pooled effect size. Additionally, sensitivity analysis showed l-carnitine supplementation could improve glycaemic control, particularly along with hypocaloric diet. CONCLUSION This meta-analysis showed that l-carnitine supplementation could improve lipid profile levels, particularly in doses more than 1500 mg/day. More RCTs with large sample sizes, focusing on gut microbiome profiles and dietary patterns are needed to better understand the effect of l-carnitine on patients with cardiovascular risk factors.
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10.
Influence of Besifovir Dipivoxil Maleate Combined with L-Carnitine on Hepatic Steatosis in Patients with Chronic Hepatitis B.
Jung, YW, Kim, M, Kim, BK, Park, JY, Kim, DY, Ahn, SH, Han, KH, Kim, SU
Journal of Korean medical science. 2020;(17):e104
Abstract
BACKGROUND Besifovir dipivoxil maleate (BSV) with L-carnitine is the first-line antiviral agent for chronic hepatitis B (CHB) infection. We investigated whether BSV combined with L-carnitine improves hepatic steatosis (HS). METHODS Treatment-naïve patients with CHB who were initiated on antiviral therapy (AVT) were enrolled. The magnitude of HS was assessed using hepatic steatosis index (HSI), and HS improvement was defined as a ≥ 10% reduction in the HSI score from the baseline. RESULTS The mean age of the study patients was 56 years with a male predominance (n = 178, 64.7%). The mean body mass index (BMI), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and platelet count were 23.5 kg/m², 49.6 IU/L, 49.0 IU/L, and 191.3 × 10⁹/L, respectively. The mean HSI and fibrosis (FIB)-4 index were 32.6 and 0.5, respectively. After 6 months of AVT, platelet count (mean, 191.3→167.0 × 10⁹/L), fasting glucose (mean, 113.1→105.9 mg/dL), AST (mean, 49.6→28.0 IU/L), ALT (mean, 49.0→33.9 IU/L), and total cholesterol (mean, 170.0→162.1 mg/dL) levels significantly decreased (all P < 0.05). In the BSV group, AST (mean, 95.2→30.2 IU/L) and ALT (mean, 81.1→31.1 IU/L) levels significantly reduced (all P < 0.05), whereas HSI and FIB-4 index were maintained (all P > 0.05). In the univariate analysis, age, BMI, diabetes, cirrhosis, fasting glucose level, and ALT were significantly associated with HS improvement (all P < 0.05). CONCLUSION BSV with L-carnitine did not show any improvement of HS in patients with CHB. Further prospective randomized controlled studies are needed to validate the potential beneficial effects of BSV with L-carnitine in CHB infection.