Plasma L-carnitine Research Articles

Epididymal sonographic findings in infertile males with isolated asthenozoospermia and their correlation with seminal plasma l-carnitine: An observational study.

The present study aimed to show epididymal sonographic findings in infertile males with isolated asthenozoospermia as well as their correlation with seminal plasma l-carnitine. Eighty married men were recruited in the study. Fifty infertile men with isolated asthenozoospermia and 30 fertile controls with normal semen parameters were included. Semen analysis was done with estimation of seminal plasma l-carnitine level. Scrotal ultrasonography was used as the diagnostic method for assessing epididymal morphology. Epididymal heterogeneous echogenicity was significantly higher in the infertile group compared to the controls. Whereas homogeneous epididymal echotexture and seminal plasma l-carnitine levels were significantly higher in the controls compared to the infertile patients. Interestingly, it was observed that within each group, seminal l-carnitine and sperm total motility were significantly higher in those with homogeneous rather than heterogeneous epididymal echotexture. Our study demonstrated a significant association between epididymal echo-texture, seminal plasma l-carnitine and sperm motility. Thus, we recommend performing epididymal sonographic evaluation as one of the basic investigations for infertile men.

Simultaneous determination of choline, L-carnitine, betaine, trimethylamine, trimethylamine N-oxide, and creatinine in plasma, liver, and feces of hyperlipidemic rats by UHPLC-MS/MS

BackgroundDue to the close correlation between choline, L-carnitine, betaine and their intestinal microbial metabolites, including trimethylamine (TMA) and trimethylamine N-oxide (TMAO), and creatinine, there has been an increasing interest in the study of these compounds in vivo. MethodsIn this study, a rapid stable isotope dilution (SID)-UHPLC-MS/MS method was developed for the simultaneous determination of choline, L-carnitine, betaine, TMA, TMAO and creatinine in plasma, liver and feces of rats. The method was validated using quality control (QC) samples spiked at low, medium and high levels. Second, we applied the method to quantify the effects of Rosa Roxburghii Tratt juice (RRTJ) on plasma, liver, and fecal levels of choline, L-carnitine, betaine, TMA, TMAO, and creatinine in high-fat diet-induced hyperlipidemic rats, demonstrating the utility of the method. ResultsThe limits of detection (LOD) were 0.04–0.027 µM and the limits of quantification (LOQ) were 0.009–0.094 µM. The linear ranges for each metabolite in plasma were choline1.50–96 µM; L-carnitine: 2–128 µM; betaine: 3–192 µM; TMA: 0.01–40.96 µM; TMAO: 0.06–61.44 µM and creatinine: 1–64 µM (R2 ≥ 0.9954). The linear ranges for each metabolite in liver were Choline: 12–768 µM; L-carnitine: 1.5–96 µM; betaine: 10–640 µM; TMA: 0.5–32 µM; TMAO: 0.02–81.92 µM and creatinine: 0.2–204.8 µM (R2 ≥ 0.9938). The linear ranges for each metabolite in feces were choline: 1.5–96 µM; L-carnitine: 0.01–40.96 µM; Betaine: 1.5–96 µM; TMA: 1–64 µM; TMAO: 0.02–81.92 µM and Creatinine: 0.02–81.92 µM (R2 ≥ 0.998). The intra-day and inter-day coefficients of variation were < 8 % for all analytes. The samples were stabilized after multiple freeze–thaw cycles (3 freeze–thaw cycles), 24 h at room temperature, 24 h at 4 °C and 20 days at −80 °C. The samples were stable. The average recovery was 89 %-99 %. This method was used to quantify TMAO and its related metabolites and creatinine levels in hyperlipidemic rats. The results showed that high-fat diet led to the disorder of TMAO and its related metabolites and creatinine in rats, which was effectively improved after the intervention of Rosa Roxburghii Tratt juice（RRTJ）. ConclusionsA method for the determination of choline, L-carnitine, betaine, TMA, TMAO and creatinine in plasma, liver and feces samples was established, which is simple, time-saving, high precision, accuracy and recovery.

Plasma trimethylamine N-oxide metabolites in the second trimester predict the risk of hypertensive disorders of pregnancy: a nested case-control study.

The relationship between gut microbiota products trimethylamine oxide (TMAO) and related metabolites including betaine, choline and L-carnitine and hypertensive disorders of pregnancy (HDP) is unclear. In order to examine whether plasma TMAO and related metabolites predict the risk of HDP, a nested case-control study was conducted in Chinese women based on a prospective cohort including 9447 participants. 387 pairs of pregnant women (n = 774) were matched and their plasma TMAO, betaine, choline, and L-carnitine at 16-20 gestational weeks were measured by liquid chromatography-mass spectrometry. Odds ratio (OR) and the 95% confidence interval (95% CI) were calculated using the conditional logistic regression, to examine the association between TMAO metabolites and HDP. The findings showed that higher plasma betaine (≥24.94 μmol/L) was associated with a decreased risk of HDP and its subtype gestational hypertension (GH), with adjusted ORs of 0.404 (95% CI: 0.226-0.721) and 0.293 (95% CI: 0.134-0.642), respectively. Higher betaine/choline ratio (>2.64) was associated with a lower risk of HDP and its subtype preeclampsia or chronic hypertension with superimposed preeclampsia (PE/CH-PE), with adjusted ORs of 0.554 (95% CI: 0.354-0.866) and 0.226 (95% CI: 0.080-0.634). Moreover, compared with traditional factors (TFs) model, the TMAO metabolites+ TFs model had a higher predictive ability for PE/CH-PE (all indexes P values < 0.0001). Therefore, it suggests that the detection of plasma betaine and choline in the early second trimester of pregnancy can better assess the risk of HDP.

Association between plasma L-carnitine levels and mitochondrial DNA copy number

Mitochondria are key cytoplasmic organelles in eukaryotic cells that generate adenosine triphosphate (ATP) through the electron transport chain and oxidative phosphorylation. Mitochondrial DNA (mtDNA) copy number (mtDNAcn) is considered a biomarker for both mitochondrial quantity and function as well as cellular oxidative stress level. Previous epidemiologic findings revealed that weight gain, higher body mass index (BMI), smoking, and high insulinemic potential of lifestyle were associated with lower leukocyte mtDNAcn. Carnitines are a group of compounds that play a critical role in energy production. We quantified the associations of plasma L-carnitine levels with leukocyte mtDNAcn. We then examined the association between mtDNAcn and L-carnitine (HMDB0000062) in 538 U.S. men without cancers, diabetes, or cardiovascular disease at blood collection from the Health Professionals Follow-Up Study (HPFS). We found a significant inverse association between L-carnitine and mtDNAcn (ρ = −0.1, P = 0.02). This implies that the carnitine metabolic pathway may be associated with mitochondrial function and oxidative stress.

Changes in Choline Metabolites and Ceramides in Response to a DASH-Style Diet in Older Adults.

This feeding trial evaluated the impact of the Dietary Approaches to Stop Hypertension diet on changes in plasma choline, choline metabolites, and ceramides in obese older adults; 28 adults consumed 3oz (n = 15) or 6oz (n = 13) of beef within a standardized DASH diet for 12 weeks. Plasma choline, betaine, methionine, dimethylglycine (DMG), phosphatidylcholine (PC), lysophosphotidylcholine (LPC), sphingomyelin, trimethylamine-N-oxide (TMAO), L-carnitine, ceramide, and triglycerides were measured in fasted blood samples. Plasma LPC, sphingomyelin, and ceramide species were also quantified. In response to the study diet, with beef intake groups combined, plasma choline decreased by 9.6% (p = 0.012); DMG decreased by 10% (p = 0.042); PC decreased by 51% (p < 0.001); total LPC increased by 281% (p < 0.001); TMAO increased by 26.5% (p < 0.001); total ceramide decreased by 22.1% (p < 0.001); and triglycerides decreased by 18% (p = 0.021). All 20 LPC species measured increased (p < 0.01) with LPC 16:0 having the greatest response. Sphingomyelin 16:0, 18:0, and 18:1 increased (all p < 0.001) by 10.4%, 22.5%, and 24%, respectively. In contrast, we observed that sphingomyelin 24:0 significantly decreased by 10%. Ceramide 22:0 and 24:0 decreased by 27.6% and 10.9% (p < 0.001), respectively, and ceramide 24:1 increased by 36.8% (p = 0.013). Changes in choline and choline metabolites were in association with anthropometric and cardiometabolic outcomes. These findings show the impact of the DASH diet on choline metabolism in older adults and demonstrate the influence of diet to modify circulating LPC, sphingomyelin, and ceramide species.

Carnitine metabolites and cognitive improvement in patients with schizophrenia treated with olanzapine: a prospective longitudinal study.

Objective: Cognitive impairment is one of the core symptoms of schizophrenia, which is stable and lifelong. L-carnitine has been shown to improve cognitive function and decrease the rate of cognitive deterioration in patients with Alzheimer's disease. However, it remains unclear regarding the role of L-carnitine and its metabolites in cognitive functions in schizophrenia after treatment with olanzapine. The purpose of this study was to evaluate the relationship between changes in plasma levels of L-carnitine metabolites and cognitive improvement after olanzapine treatment. Methods: This was a prospective longitudinal study. In this study, we recruited 25 female patients with first episode schizophrenia (FES) who were drug naïve at baseline and received 4 weeks of olanzapine monotherapy. Cognitive function was assessed at baseline and 4-week follow-up using the RBANS. Plasma L-carnitine metabolite levels were determined by a metabolomics technology based on untargeted ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Results: We found that the immediate memory index, delayed memory index and RBANS composite score were significantly increased at the 4-week follow-up after treatment. A total of 7 differential L-carnitine metabolites were identified in FES patients after olanzapine monotherapy. In addition, we found that changes in butyrylcarnitine were positively correlated with improvements in language index and RBANS composite score. Further regression analyses confirmed the association between reduced butyrylcarnitine levels and cognitive improvement after olanzapine monotherapy in FES patients. Conclusion: Our study shows that cognitive improvement after olanzapine treatment was associated with changes in L-carnitine metabolite levels in patients with FES, suggesting a key role of L-carnitine in cognition in schizophrenia.

Metabolomic profiles of 38 acylcarnitines in major depressive episodes before and after treatment.

Major depression is associated with changes in plasma L-carnitine and acetyl-L-carnitine. But its association with acylcarnitines remains unclear. The aim of this study was to assess metabolomic profiles of 38 acylcarnitines in patients with major depression before and after treatment compared to healthy controls (HCs). Metabolomic profiles of 38 plasma short-, medium-, and long-chain acylcarnitines were performed by liquid chromatography-mass spectrometry in 893 HCs from the VARIETE cohort and 460 depressed patients from the METADAP cohort before and after 6 months of antidepressant treatment. As compared to HCs, depressed patients had lower levels of medium- and long-chain acylcarnitines. After 6 months of treatment, increased levels of medium- and long-chain acyl-carnitines were observed that no longer differed from those of controls. Accordingly, several medium- and long-chain acylcarnitines were negatively correlated with depression severity. These medium- and long-chain acylcarnitine dysregulations argue for mitochondrial dysfunction through fatty acid β-oxidation impairment during major depression.

Neither Trimethylamine-N-Oxide nor Trimethyllysine Is Associated with Atherosclerosis: A Cross-Sectional Study in Older Japanese Adults.

Recent evidence suggests that trimethylamine-N-oxide (TMAO), a metabolite of L-carnitine and choline, is linked to atherosclerosis and cardiovascular diseases. As TMAO content is very high in fish, we raised the following question: why do Japanese people, who consume lots of fish, show a low risk of atherosclerosis? To address this question, we investigated the effects of TMAO and other L-carnitine-related metabolites on carotid intima-media thickness (IMT). Participants were recruited from a small island and a mountainous region. Plasma L-carnitine, γ-butyrobetaine (γBB), TMAO, trimethyllysine (TML), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) levels were measured using liquid or gas chromatography-mass spectrometry. Plasma L-carnitine concentration was higher in men than in women. TMAO and TML were significantly higher in the residents of the island than in the mountainous people. In multiple linear regression analyses in all participants, TML showed a significant inverse association with max-IMT and plaque score (PS), whereas TMAO did not show any associations. In women, L-carnitine was positively associated with max-IMT and PS. TMAO was correlated with both EPA and DHA levels, implying that fish is a major dietary source of TMAO in Japanese people. Our study found that plasma TMAO was not an apparent risk factor for atherosclerosis in elderly Japanese people, whereas a low level of TML might be a potential risk. L-carnitine may be a marker for atherosclerosis in women.

Age and APOE affect L-carnitine system metabolites in the brain in the APOE-TR model.

With age the apolipoprotein E (APOE) E4 allele (involved in lipid homeostasis) is associated with perturbation of bioenergetics pathways in Alzheimer's disease (AD). We therefore hypothesized that in aging mice APOE genotype would affect the L-carnitine system (central to lipid bioenergetics), in the brain and in the periphery. Using liquid chromatography-mass spectrometry, levels of L-carnitine and associated metabolites: γ-butyrobetaine (GBB), crotonobetaine, as well as acylcarnitines, were evaluated at 10-, 25-, and 50-weeks, in the brain and the periphery, in a targeted replacement mouse model of human APOE (APOE-TR). Aged APOE-TR mice were also orally administered 125 mg/kg of L-carnitine daily for 7 days followed by evaluation of brain, liver, and plasma L-carnitine system metabolites. Compared to E4-TR, an age-dependent increase among E2- and E3-TR mice was detected for medium- and long-chain acylcarnitines (MCA and LCA, respectively) within the cerebrovasculature and brain parenchyma. While following L-carnitine oral challenge, E4-TR mice had higher increases in the L-carnitine metabolites, GBB and crotonobetaine in the brain and a reduction of plasma to brain total acylcarnitine ratios compared to other genotypes. These studies suggest that with aging, the presence of the E4 allele may contribute to alterations in the L-carnitine bioenergetic system and to the generation of L-carnitine metabolites that could have detrimental effects on the vascular system. Collectively the E4 allele and aging may therefore contribute to AD pathogenesis through aging-related lipid bioenergetics as well as cerebrovascular dysfunctions.

Plasma Cholesterol- and Body Fat-Lowering Effects of Chicken Protein Hydrolysate and Oil in High-Fat Fed Male Wistar Rats.

Rest raw materials provide a new source of bioactive dietary ingredients, and this study aimed to determine the health effects of diets with chicken protein hydrolysate (CPH) and chicken oil (CO) generated from deboned chicken meat. Male Wistar rats (n = 56) were divided into seven groups in three predefined sub-experiments to study the effects of protein source (casein, chicken fillet, pork fillet, and CPH), the dose-effect of CPH (50% and 100% CPH), and the effects of combining CPH and CO. Rats were fed high-fat diets for 12 weeks, and casein and chicken fillet were used as controls in all sub-experiments. While casein, chicken-, or pork fillet diets resulted in similar weight gain and plasma lipid levels, the CPH diet reduced plasma total cholesterol. This effect was dose dependent and accompanied with the reduced hepatic activities of acetyl-CoA carboxylase and fatty acid synthase. Further, rats fed combined CPH and CO showed lower weight gain, and higher hepatic mitochondrial fatty acid oxidation, plasma L-carnitine, short-chain acylcarnitines, TMAO, and acetylcarnitine/palmitoylcarnitine. Thus, in male Wistar rats, CPH and CO lowered plasma cholesterol and increased hepatic fatty acid oxidation compared to whole protein diets, pointing to potential health-beneficial bioactive properties of these processed chicken rest raw materials.

Chaihu-Guizhi-Ganjiang Decoction is more efficacious in treating irritable bowel syndrome than Dicetel according to metabolomics analysis

BackgroundChaihu-Guizhi-Ganjiang Decoction (CGGD) is a traditional Chinese medicine (TCM) prescription used to treat viral influenza. There is evidence that CGGD can be used to treat irritable bowel syndrome (IBS) but the potential mechanism of action and metabolites produced upon CGGD treatment remains elusive.MethodsPatients with IBS were treated with pinaverium bromide (Dicetel™) and then CGGD after a washout period of 1 week. Both treatments lasted for 30 days. The efficacy and changes of metabolites in plasma after the two treatments were compared. Plasma samples were acquired before and after each treatment, and untargeted metabolics analysis was performed.ResultsEfficacy was measured according to the Rome IV criteria and TCM theory. Our results indicated that CGGD showed significantly better efficacy than Dicetel in the treatment of IBS utilizing each criterion. CGGD exerted greater effects on plasma metabolism than Dicetel. Dicetel treatment led to increased tryptophan metabolism (increased levels of 5-Hydroxyindoleacetaldehyde) and increased protein metabolism (increased levels of L-arginine). CGGD treatment significantly (p < 0.05) increased carnitine metabolism, with elevated levels of L-carnitine and acylcarnitine in plasma. Such changes in these metabolites could exert effects against IBS by improving gastrointestinal motility and suppressing pain, depression, and inflammation.ConclusionsCGGD appeared to be more efficacious than Dicetel for treating patients with IBS. The findings provide a sound support for the underlying biomolecular mechanism of CGGD in the prevention and treatment of IBS.

​Study of the Relationship between the Levels of L-carnitine and NO Metabolites in Blood Plasma and Seminal Plasma in Stallions

Background: Artificial insemination with chilled sperm is a reproductive biotechnology often used in horse breeding. However, maintaining the acceptable sperm quality after cooling, which affects the frequency of pregnancy, remains an urgent problem at the present time. Therefore, clarifying the role of important physiological metabolites, such as L-carnitine and nitric oxide, is a significant aspect in terms of possible improvement of the quality of cryopreserved sperm. Methods: The study included 35 breeding stallions, 27 of which were stallions of the Arabian breed and 8 were of the Soviet heavy draft breed. The content of total, free and bound carnitine and NO metabolites was determined by photometric method in the samples of seminal plasma and blood plasma. The correlation coefficient between the content of L-carnitine and the level of NO metabolites was also determined. Result: We have found a direct moderate correlation between the level of total and free L-carnitine in the seminal plasma and blood plasma. The study has also revealed a positive correlation between the level of all L-carnitine fractions and NO metabolites in seminal plasma. In addition, there was a positive correlation between the total L-carnitine of blood plasma and NO metabolites in seminal plasma.

Plasma l-carnitine and risks of cardiovascular events and recurrent stroke after ischemic stroke: A nested case-control study

Background and aimsl-Carnitine was suggested to prevent the progression of atherosclerosis, myocardial and neurologic injury, and exhibited cardioprotective effects. However, epidemiological data on circulating l-carnitine and risks of cardiovascular events in the setting of stroke is rare. We aimed to explore the relationships between plasma l-carnitine and cardiovascular events and stroke recurrence after ischemic stroke in a nested case-control study. Methods and resultsA total of 323 cardiovascular events (including 264 recurrent strokes) and 323 matched controls (free of recurrent cardiovascular events) were included. Study outcomes included cardiovascular events and recurrent stroke after ischemic stroke. Plasma l-carnitine concentrations were measured by ultra-high-performance LC-MS/MS. Conditional logistic regression models were used to estimate odds ratios (ORs) of stroke outcomes. Plasma l-carnitine was inversely associated with cardiovascular events (OR = 0.69, 95% CI: 0.57–0.84 per SD) and recurrent stroke (OR = 0.72, 95% CI: 0.58–0.88 per SD) after adjusting for established risk confounders. Compared with the lowest tertile of l-carnitine, adjusted ORs of cardiovascular events and recurrent stroke for participants in the highest tertiles were 0.35 (95% CI: 0.21–0.57) and 0.36 (95% CI: 0.21–0.62), respectively. In addition, l-carnitine provided incremental predictive ability beyond established risk factors, shown by increase in C statistics, net reclassification improvement and integrated discrimination improvement. ConclusionsHigher l-carnitine levels were associated with lower risks of cardiovascular events and recurrent stroke after ischemic stroke. Our findings provided evidence supporting plasma l-carnitine as a potential prognostic marker in risk discrimination and stratification in patients with ischemic stroke. Trial registrationClinicaltrials.gov as NCT01840072. URL: https://www.clinicaltrials.gov.

Effect of L-carnitine on the Lipid Profile, Glycemic Control, Oxidative Stress, and Anthropometric Indices of Individuals with Type 2 Diabetes

Diabetes mellitus is one of the most prevalent metabolic diseases in existence. With more than 536.6 million cases having been diagnosed globally, its prevalence is reported to be 10.5% in 2021. In individuals with diabetes, plasma L-carnitine is low and metabolized abnormally. In this review, we aimed to assess whether L-carnitine supplementation is correlated with a reduction of the risk of cardiovascular diseases in individuals with diabetes by improving the compositions of lipid profiles, indicators of oxidative stress, glycemic control, and anthropometric indices. A literature search in major databases such as Web of Science, PubMed, Google Scholar, Scopus, and Scientific Information Database was conducted until November 2021. This was done in conjunction with a search in Elsevier and SpringerLink databases, resulting in the inclusion of relevant articles in this review. To construct the search strategy, “Carnitine” OR “glycine propionyl carnitine” OR “Acetylcarnitine” in combination with “Diabetes Mellitus” OR “Diabetes Complications” OR “Lipid Profile” and all of its components were used to search for and within the articles and databases. After screening, 10 articles published between 1998 and 2017 were identified. They evaluated the effect of L-carnitine on lipid profile metabolism, glycemic control, anthropometric indices, and oxidative stress markers in individuals with diabetes. In this systematic review, we concluded that L-carnitine had no notable effect on lipid profile as well as glycemic control and anthropometric indices. Therefore, using L-carnitine probably has no notable effect on metabolic status in individuals with diabetes. Meanwhile, some articles suggested that L-carnitine may have positive effects on some oxidative stress indicators.

Association Between Plasma L-Carnitine and Cognitive Impairment in Patients with Acute Ischemic Stroke.

L-carnitine has been shown to exert neuroprotective effects on cerebral ischemia, mainly by improving mitochondrial function and reducing inflammation. L-carnitine supplementation has also been promoted to enhance cognitive function. However, the relationship between L-carnitine and cognitive impairment after ischemic stroke has seldom been studied. We aimed to evaluate the association between plasma L-carnitine and poststroke cognitive impairment. The study sample population was drawn from the China Antihypertensive Trial in Acute Ischemic Stroke. Plasma L-carnitine were measured at baseline in 617 patients with ischemic stroke using ultrahigh-performance liquid chromatography-tandem mass spectrometry. Cognitive function was evaluated using the Montreal Cognitive Assessment at 3-month follow-up after ischemic stroke. Plasma L-carnitine were inversely associated with cognitive impairment at 3 months after ischemic stroke, and the adjusted odds ratio (95% CI) for the highest versus lowest quartiles of L-carnitine was 0.60 (0.37, 0.98; p for trend = 0.04). Each 1-SD increase in log-transformed L-carnitine concentration was significantly associated with a 15% (95% CI: 1%, 29%) reduction in the risk of cognitive impairment after stroke. The addition of L-carnitine to the model including conventional risk factors significantly improved the risk reclassification for cognitive impairment (net reclassification improvement: 17.9%, integrated discrimination improvement: 0.8%; both p < 0.05). Furthermore, joint effects of L-carnitine and inflammation markers were observed, and patients with higher L-carnitine and a lower inflammatory status simultaneously had the lowest risk of poststroke cognitive impairment. The present study provided prospective evidence on the inverse association between plasma L-carnitine and cognitive impairment after ischemic stroke.

Levels of L-carnitine in human seminal plasma are associated with sperm fatty acid composition.

The fatty acid composition of spermatozoa has been shown to be important for their function, and L-carnitine is crucial for fatty acid metabolism. Its levels in the seminal plasma positively correlate with semen quality, whereas high body mass index (BMI) is associated with both reduced semen quality and altered sperm fatty acid composition. Here, we examined the associations between free seminal L-carnitine levels and sperm fatty acid composition as well as BMI. Semen samples were collected and analyzed from 128 men with unknown fertility status and with BMI ranging from 19 kg m−2 to 63 kg m−2. Sperm fatty acid composition was assessed by gas chromatography, while free seminal L-carnitine analysis was performed using high-performance liquid chromatography. Multiple linear regression analysis showed a positive correlation of free seminal L-carnitine levels with the amount of sperm palmitic acid (β = 0.21; P = 0.014), docosahexaenoic acid (DHA; β = 0.23; P = 0.007), and total n-3 polyunsaturated fatty acids (β = 0.23; P = 0.008) and a negative correlation of free seminal L-carnitine levels with lignoceric acid (β = −0.29; P = 0.001) and total n-6 polyunsaturated fatty acids (β = −0.24; P = 0.012) when adjusted for covariates. There was no relationship between free seminal L-carnitine levels and BMI. Since free seminal L-carnitine levels are associated with semen quality, the absence of a correlation with BMI suggests that reduced semen quality in obese men is independent of seminal L-carnitine.

Seminal L-Carnitine In Infertile Oligoasthenoteratozoospermic Men with Varicocele.

Background:Few studies have investigated the relationship of seminal L-Carnitine (LC) with male infertility associated with varicocele. The purpose of this prospective cross-sectional study was to assess seminal plasma LC levels in infertile oligoathenoteratozoospermic (OAT) men with varicocele.Methods:Overall, 86 men were investigated. They were divided into infertile OAT men with varicocele (n=45), infertile OAT men without varicocele (n=21), and fertile men (n=20) as a control group. According to WHO guidelines, these men were subjected to history taking, clinical examination, and semen analysis. Seminal LC levels were evaluated by the colorimetric method. Statistical comparisons were done using Kruskal-Wallis and Mann-Whitney U tests and correlations were verified by the Pearson test. P-value<0.05 was set to be statistically significant.Results:The mean seminal plasma LC levels were significantly lower in infertile OAT men with varicocele (216.3±57.1 ng/ml) compared to infertile OAT men without varicocele (252.9±62.9 ng/ml, p=0.01), or fertile men (382.8±63.6 ng/ml, p=0.001). Besides, the mean seminal plasma LC level exhibited statistically significant decreases in infertile OAT men of varicocele grade III compared to varicocele grade II cases, and in infertile OAT men with bilateral varicocele compared with unilateral varicocele cases. Collectively, there was a statistically significant positive correlation between seminal LC levels with sperm concentration, motility, and normal morphology.Conclusion:Seminal LC levels are expressively reduced in infertile OAT men with varicocele and are influenced by an increase in varicocele grade and laterality.

Impact of dietary supplements based on L-carnitine on free-radical processes in model systems

Introduction. According to the results of numerous studies and meta-analyses, the effectiveness of male infertility therapy with micronutrients-antioxidants in various variants remains low, especially concerning the increase in live-birth rates and the incidence of clinical pregnancy. This may be due to both the empirical nature of such therapy with an imbalance of ejaculate redox systems, and an overdose of individual ingredients of antioxidant complexes.Purpose of the study. To evaluate the antioxidant activity of complex preparation based on L-carnitine for the treatment of male infertility in an experimental model system.Materials and methods. The dietary supplements «AndroDoz®» («Nizhfarm» JSC, Russian Federation) and «Proxeed® plus» (Sigma-Tau Pharmaceuticals Inc., Italy) were tested. The antioxidant properties of the preparations were determined in vitro by recording chemiluminescence in model systems generating reactive oxygen species using the «LKB-Wallac 1256 chemiluminometer» (Wallac Oy/PerkinElmer®, Finland). Chemiluminescence was evaluated by the light sum and the maximum amplitude of the glow, the antioxidant activity in the biological environment was studied when adding drugs to chicken yolk lipids similar to blood lipoprotein complexes.Results. The introduction of «AndroDoz®» and «Proxeed® plus» into the incubation medium in an amount comparable to the physiological level of L-carnitine in seminal plasma, inhibited the luminescence of the model system. At the same time, if «Proxeed® plus» almost completely inhibited the formation of radicals, then an equivalent dose of «AndroDoz®» reduced the intensity of chemiluminescence by 60%. Approximately in the same proportions, the preparations suppressed the intensity of lipid peroxidation processes in a model system with lipoprotein complexes similar to blood lipids, that is, the antioxidant activity was preserved in the biological environment. A decrease in the value of the chemiluminescence light sum was also found against the background of the use of these dietary supplements, which may indicate their protective effect on biological membranes, including subcellular structures of spermatozoa.Conclusion. The combined dietary supplements used in the study have a high antioxidant potential. The preparation «Proxeed® plus» can completely suppress the processes of lipoperoxidation with the possible development of a deficiency of free radicals that provide vital processes. The preparation «AndroDoz®» has a milder effect on free-radical phenomena probably due to a lower content of active ingredients and a balanced composition, which reduces the risk of complications in the form of an «antioxidant paradox» or reductive stress.

Ten-year changes in plasma L-carnitine levels and risk of coronary heart disease.

L-Carnitine is abundant in animal source foods, particularly red meat, and circulating L-carnitine may be related to the incidence of coronary heart disease (CHD). We investigated whether long-term changes in plasma L-carnitine over 10years were associated with the CHD incidence and also examined joint associations of carnitine-rich red meat consumption and L-carnitine changes on the subsequent risk of CHD. This prospective nested case-control study included 772 healthy women at baseline (386 incident CHD cases and 386 healthy controls). Plasma L-carnitine levels were measured both at the first (1989-90) and second blood collections (2000-02). Incident cases of CHD were prospectively followed from the date of the second blood collection through 2016. Overall, a greater increase in L-carnitine from the first to the second time point was related to a higher risk of CHD, regardless of the initial L-carnitine levels (relative risk: 1.36 (95% CI 0.999, 1.84) per 1-SD increase). The 10-year changes in L-carnitine were positively associated with red meat consumption over time, and women with higher red meat intake (≥ 36g/day) and with greater increases in L-carnitine had a 1.86 (95% CI 1.13, 3.09) times increased risk of CHD, as compared to those with lower red meat intake and lesser increases in L-carnitine. Long-term increases in L-carnitine levels were associated with the subsequent incidence of CHD, especially among women with higher intake of red meat. Our results suggest the importance of atherogenic L-carnitine changes and dietary intakes over time in the prevention of CHD.

Association between plasma L-carnitine and the risk of cognitive impairment in patients with acute ischemic stroke

Background and Aims: L-carnitine has been shown to exert neuroprotective effects against cerebral ischemia, mainly through improving mitochondrial function and reducing inflammation. L-carnitine supplementation has also been promoted to enhance cognitive function. However, the relationship between L-carnitine and cognitive impairment after ischemic stroke has been sparsely studied. We aimed to evaluate the prospective association between plasma levels of L-carnitine and post-stroke cognitive impairment.