L-carnitine infusions may suppress serum C-reactive protein and improve nutritional status in maintenance hemodialysis patients

The frequency of periodontitis in end-stage renal disease on hemodialysis in a sample of Egyptian population: multi-center clinical cross-sectional study

BACKGROUND

There is a general assumption that periodontal disease is highly prevalent among patients with chronic renal failure undergoing hemodialysis. The aim of the study to estimate the frequency of periodontitis in patients on hemodialysis among a sample of the Egyptian population, as well as the correlation between different clinical parameters of periodontal status with serum creatinine and blood urea. This may rule out the bidirectional relationship between periodontitis and renal failure in patients on hemodialysis.

METHODS

The study was conducted on 263 hemodialysis patients (165 males and 98 females) at three dialysis centers in Benha Governorate, Egypt (Benha Hospital, Tukh hospital, Qalyub hospital). Periodontal parameters including plaque index (PI), gingival index (GI), clinical attachment level (CAL), and probing pocket depth (PPD) had been recorded in these patients. Serum urea and creatinine levels had been measured, the data had been collected and undergone statistical analysis.

RESULTS

Frequency of periodontitis was 85.6% with stage III is the most prevalent stage. There was a significant positive strong correlation between age and periodontitis stage (rs = 0.707, p < 0.001). There was a positive correlation between clinical parameters and serum creatinine level.

CONCLUSION

In the present study, a high frequency of periodontitis had been found among ESRD patients on hemodialysis in the severe form (stage III) periodontitis. There was a significant direct correlation between the severity of periodontitis and CAL with a duration of hemodialysis. There was a weak insignificant association between periodontal indices (PD, BOP, and plaque score) and duration of hemodialysis.

Carnitine Palmitoyltransferase System: A New Target for Anti-Inflammatory and Anticancer Therapy?

Lipid metabolism involves multiple biological processes. As one of the most important lipid metabolic pathways, fatty acid oxidation (FAO) and its key rate-limiting enzyme, the carnitine palmitoyltransferase (CPT) system, regulate host immune responses and thus are of great clinical significance. The effect of the CPT system on different tissues or organs is complex: the deficiency or over-activation of CPT disrupts the immune homeostasis by causing energy metabolism disorder and inflammatory oxidative damage and therefore contributes to the development of various acute and chronic inflammatory disorders and cancer. Accordingly, agonists or antagonists targeting the CPT system may become novel approaches for the treatment of diseases. In this review, we first briefly describe the structure, distribution, and physiological action of the CPT system. We then summarize the pathophysiological role of the CPT system in chronic obstructive pulmonary disease, bronchial asthma, acute lung injury, chronic granulomatous disease, nonalcoholic fatty liver disease, hepatic ischemia–reperfusion injury, kidney fibrosis, acute kidney injury, cardiovascular disorders, and cancer. We are also concerned with the current knowledge in either preclinical or clinical studies of various CPT activators/inhibitors for the management of diseases. These compounds range from traditional Chinese medicines to novel nanodevices. Although great efforts have been made in studying the different kinds of CPT agonists/antagonists, only a few pharmaceuticals have been applied for clinical uses. Nevertheless, research on CPT activation or inhibition highlights the pharmacological modulation of CPT-dependent FAO, especially on different CPT isoforms, as a promising anti-inflammatory/antitumor therapeutic strategy for numerous disorders.

Effect of L-Carnitine Supplementation on Inflammatory Markers and Serum Glucose in Hemodialysis Children: A Randomized, Placebo-Controlled Clinical Trial

OBJECTIVES

Chronic inflammation is present in a high proportion of the chronic kidney disease (CKD) population, which can increase the risk of cardiovascular disease. Moreover, it is known as the leading cause of death in these patients. In addition, change in glucose metabolism is another common problem among CKD population. In this regard, it was found that insulin resistance and inflammation can perpetuate each other and simultaneously cause atherosclerosis. Because some studies have previously shown the positive effects of L-carnitine on reducing inflammation and controlling blood sugar, in the present study, we examined the effects of L-carnitine supplementation on serum inflammatory markers, fasting blood sugar (FBS), free carnitine (FC), albumin levels, and quality of life score among children on hemodialysis.

METHOD

Twenty-four children on hemodialysis (aged between 6 and 18 years) were enrolled in this randomized clinical trial study. Thereafter, 12 patients received 50 mg/kg of L-carnitine and 12 patients received placebo for a 10-week period. Afterward, we determined serum FC, interleukin-6 (IL-6), high-sensitivity C-reactive protein, FBS, and albumin and Pediatrics Quality of Life scores once at the baseline and once after performing intervention for 10 weeks. Moreover, the one-way repeated measures analysis was used to evaluate the effects of L-carnitine supplementation.

RESULTS

Although oral L-carnitine supplementation led to the decreased high-sensitivity C-reactive protein, this change was not significant compared with the placebo. Also, L-carnitine supplementation has significantly reduced serum levels of IL-6 and FBS, which has also raised serum FC and Pediatrics Quality of Life scores compared with the placebo. Notably, no significant change was observed in serum albumin levels.

CONCLUSION

Given the significant reductions in IL-6 and FBS levels, L-carnitine supplementation appeared to have some positive effects on the inflammation, blood glucose control, and prevention of cardiovascular events in these patients, as well as the improvement of quality of life. In this regard, L-carnitine therapy with a longer duration is recommended to obtain more effective results.

Significance of Levocarnitine Treatment in Dialysis Patients

Carnitine is a naturally occurring amino acid derivative that is involved in the transport of long-chain fatty acids to the mitochondrial matrix. There, these substrates undergo β-oxidation, producing energy. The major sources of carnitine are dietary intake, although carnitine is also endogenously synthesized in the liver and kidney. However, in patients on dialysis, serum carnitine levels progressively fall due to restricted dietary intake and deprivation of endogenous synthesis in the kidney. Furthermore, serum-free carnitine is removed by hemodialysis treatment because the molecular weight of carnitine is small (161 Da) and its protein binding rates are very low. Therefore, the dialysis procedure is a major cause of carnitine deficiency in patients undergoing hemodialysis. This deficiency may contribute to several clinical disorders in such patients. Symptoms of dialysis-related carnitine deficiency include erythropoiesis-stimulating agent-resistant anemia, myopathy, muscle weakness, and intradialytic muscle cramps and hypotension. However, levocarnitine administration might replenish the free carnitine and help to increase carnitine levels in muscle. This article reviews the previous research into levocarnitine therapy in patients on maintenance dialysis for the treatment of renal anemia, cardiac dysfunction, dyslipidemia, and muscle and dialytic symptoms, and it examines the efficacy of the therapeutic approach and related issues.

The efficacy of L-carnitine in improving malnutrition in patients on maintenance hemodialysis: a meta-analysis

The improvement of malnutrition with levocarnitine in maintenance hemodialysis (MHD) patients is controversial. We performed a meta-analysis to evaluate the efficacy of levocarnitine in improving malnutrition in MHD patients. We performed a literature search for relevant articles related to the treatment of malnutrition by L-carnitine in MHD patients in PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and Wanfang databases. We set the publication dates from 1950 to July 2019. The levels of albumin, prealbumin, total protein, and transferrin before and after treatment were used for assessing malnutrition. Twenty-seven studies were included in the present analysis. The results of the random effects model indicated that L-carnitine treatment improved the albumin level in patients on MHD patients. The pooled standardized mean difference of albumin level was 2.51 (95% confidence interval (CI): 2.13-2.90, P<0.001). The pooled total protein level was 3.83 (95% CI: 2.41-5.24, P = 0.000) and the pooled transferrin level was 0.35 (95% CI: 0.18-0.52, P = 0.000). Significant differences were observed with the total protein and transferrin levels. The results indicated that levocarnitine significantly improved the prealbumin level in patients on MHD. The pooled prealbumin level was 70.86 (95% CI: 42.99-98.73, P = 0.000). No publication bias was detected (P>0.05). The present meta-analysis indicated that L-carnitine can have a favorable effect on malnutrition biomarkers in patients on MHD, including the increase in albumin, total protein, transferrin, and prealbumin levels. The L-carnitine could be an option for treatment of MHD patients.

Updates on hemodialysis techniques with a common denominator: The personalization of the dialytic therapy

Hemodialysis (HD) is a life-saving therapy for patients with end-stage renal disease. In dialyzed patients, the prevalence of multi-morbidity is rising driven by various factors, such as the population aging, the incomplete correction of uremia, and the side effects of the dialysis therapy itself. Each dialyzed patient has their own specific clinical and biochemical problems. It is therefore unthinkable that the same dialysis procedure can be able to meet the needs of every patient on chronic dialysis. We have very sophisticated dialysis machines and different dialysis techniques and procedures beyond conventional HD, such as hemodiafiltration (HDF) with pre- and post-dilution, acetate-free biofiltration (AFB), hemofiltration (HF), and expanded HD. Each of these techniques has its own specific characteristics. To solve some intradialytic clinical issues, such as arterial hypotension and arrhythmias, we have biofeedback systems with automatic regulation of the blood volume, body temperature, arterial pressure, as well as potassium profiling techniques in the dialysis bath. New technical innovations, such as citrate-containing dialysate or heparin-coated membranes, could reduce the risk of bleeding. To better address to patient needs, the strengths and weaknesses of each of these systems must be well-known, in order to have a personalized dialysis prescription for each patient.

Potential roles of mitochondrial cofactors in the adjuvant mitigation of proinflammatory acute infections, as in the case of sepsis and COVID-19 pneumonia

Background

The mitochondrial cofactors α-lipoic acid (ALA), coenzyme Q10 (CoQ10) and carnitine (CARN) play distinct and complementary roles in mitochondrial functioning, along with strong antioxidant actions. Also termed mitochondrial nutrients (MNs), these cofactors have demonstrated specific protective actions in a number of chronic disorders, as assessed in a well-established body of literature.

Methods

Using PubMed, the authors searched for articles containing information on the utilization of MNs in inflammatory disorders as assessed from in vitro and animal studies, and in clinical trials, in terms of exerting anti-inflammatory actions.

Results

The retrieved literature provided evidence relating acute pathologic conditions, such as sepsis and pneumonia, with a number of redox endpoints of biological and clinical relevance. Among these findings, both ALA and CARN were effective in counteracting inflammation-associated redox biomarkers, while CoQ10 showed decreased levels in proinflammatory conditions. MN-associated antioxidant actions were applied in a number of acute disorders, mostly using one MN. The body of literature assessing the safety and the complementary roles of MNs taken together suggests an adjuvant role of MN combinations in counteracting oxidative stress in sepsis and other acute disorders, including COVID-19-associated pneumonia.

Conclusions

The present state of art in the use of individual MNs in acute disorders suggests planning adjuvant therapy trials utilizing MN combinations aimed at counteracting proinflammatory conditions, as in the case of pneumonia and the COVID-19 pandemic.

Association of Low Serum l-Carnitine Levels with Aortic Stiffness in Patients with Non-Dialysis Chronic Kidney Disease

l-carnitine (LC) is a co-factor in fatty acid metabolism; its role with respect to aortic stiffness (AS) associated with chronic kidney disease (CKD) was unclear. Our aim was to investigate associations between serum LC levels and AS in patients with non-dialysis CKD stage 3–5. The AS patients were those with carotid-femoral pulse wave velocities (cfPWV) >10 m/s; those with cfPWV ≤10 m/s were included as controls. Serum LC was measured by liquid chromatography and mass spectrometry. Of 136 CKD patients, the 44 (32.4%) with AS were older, exhibited higher rates of diabetes, and had elevated diastolic and systolic blood pressures (SBP), elevated fasting glucose levels and lower levels of serum LC compared to controls. Multivariable logistic regression revealed that serum LC (odds ratio [OR] = 0.949, 95% confidence interval [CI] 0.911–0.988, p = 0.011) and age (OR = 1.055, 95% CI 1.013–1.099, p = 0.009) were independent predictors of AS. Multivariable stepwise linear regression revealed significant positive (age and SBP) and negative (serum LC) correlations with cfPWV. The area under the curve of serum LC as a means to predict AS in CKD patients was 0.657 (95% CI 0.571–0.736, p = 0.0009). We concluded that low serum LC is a significant predictor of AS in patients diagnosed with CKD.

Impact of Glucose in Peritoneal Dialysis: Saint or Sinner?

Peritoneal dialysis (PD) solutions using glucose as osmotic agent have been used for more than two decades as effective treatment for patients with end-stage renal disease. Although alternative osmotic agents such as amino acids and macromolecular solutions, including polypeptides and glucose polymers, are now available, glucose is still the most widely used osmotic agent in PD. It has been shown to be safe, effective, readily metabolized, and inexpensive. On the other hand, it is widely assumed that exposure of the peritoneal membrane to high glucose concentrations contributes to both structural and functional changes in the dialyzed peritoneal membrane. As in diabetes, glucose, either directly or indirectly through the generation of glucose degradation products or the formation of advanced glycation end products, may contribute to peritoneal membrane failure. Although efforts to reduce glucose toxicity have been made for years, only a few suggestions, such as dual-bag systems with bicarbonate as buffer system, have found broader acceptance. Recently, some interesting new approaches to the problem of glucose-related toxicity have been made, but further investigations will be necessary before they can be used clinically. This review will focus on adverse effects of glucose in PD solutions and summarize different aspects of glucotoxicity and potential therapeutic interventions.

Kinetics of carnitine concentration after switching from oral administration to intravenous injection in hemodialysis patients

Carnitine has high dialyzability and is often deficient in dialysis patients. This deficiency is treated by either intravenous (IV) or oral supplementation of carnitine. In this study, the mode of carnitine administration was changed from oral to IV in 17 hemodialysis (HD) patients, and the treatment was discontinued after 1 year. We found that the levels of total carnitine (TC), free-carnitine (FC), and acyl-carnitine (AC) significantly increased after 3 months of switching to IV administration (p < .05). After discontinuation of carnitine administration, the TC, FC, and AC levels decreased before dialysis. The average FC value was maintained at the normal levels until 9 months, but fell below the normal values when measured at the 12th month of discontinuation. In conclusion, carnitine was maintained at significantly high levels despite the smaller dose by IV infusion as compared with that by oral administration. We therefore suggest that our results be considered while determining both the carnitine administration route and the administration period in dialysis patients under clinical settings.

Combined but not single administration of vitamin C and l-carnitine ameliorates cisplatin-induced gastric mucosa damage in male rats

Although cisplatin is a potent anticancer drug, it instigates oxidative and pro-inflammatory reactions that pose significant and distressing clinical symptoms. Therefore, this study investigated the effects of vitamin C and (or) l-carnitine on cisplatin-induced gastric mucosa damage in rat. The rats were allocated into 6 groups (n = 5). The control group received distilled water, while the treatment groups received cisplatin alone (CIP), or cisplatin with vitamin C, l-carnitine, or their combination. Cisplatin caused disruption of the gastric mucosa histoarchitecture and altered the mucus barrier function. Moreover, the stomach tissue of the CIP-treated group showed increased levels of oxidative stress markers (malondialdehyde and H₂O₂) and decreased activities of antioxidant (superoxide dismutase, glutathione peroxidase, catalase, glutathione S-transferase) and non-antioxidant (reduced glutathione) enzymes. These deleterious events were accompanied with significant increases in pro-inflammatory cytokines and inflammatory infiltration markers, myeloperoxidase and inducible nitric oxide synthase. However, the administration of both vitamin C and l-carnitine, and not either of the two showed additive effects in attenuating the adverse effects of cisplatin. The histological results agreed with the biochemical assays. The study concluded that the combined administration of vitamin C and l-carnitine, but not the single therapy, could prevent the adverse effects of cisplatin on gastric tissue.

Malnutrition, inflamation and atherosclerosis (MIA syndrome) in patients with end stage renal disease on maintenance hemodialysis (a single centre experience)

BACKGROUND

Inflammation and malnutrition play an important role in endothelial dysfunction, atherosclerosis and excessive cardiovascular morbidity and mortality in ESRD patients AIM OF THE STUDY: The primary objective is to determine the prevalence of inflammation, malnutrition and atherosclerosis in patients on maintenance haemodialysis. Secondary objective was to determine the association for atherosclerosis with inflammation and malnutrition.

PATIENT AND METHODS

One hundred and one adult patients with end stage renal disease on maintenance haemodialysis who are met with the exclusion criteria were enrolled in this cross sectional study from haemodialysis unit of Baghdad teaching hospital over the period of July/2015 - June 2016. All patients were thoroughly examined and many variables were evaluated (age, gender, blood pressure, diabetes mellitus, serum lipid profile, smoking habits, serum albumin, CRP, calcium, Phosphate, Parathyroid hormone and haemoglobin measurements). All patients underwent a carotid Doppler ultrasound study.

RESULTS

Atherosclerosis was present in 65.3%: 58.4% of patients had malnutrition and 43.6% had inflammation. The association for atherosclerosis and high CRP and low serum albumin is strong and independent of other atherosclerosis risk factors. There is significant inverse and independent correlation between CRP and albumin.

CONCLUSION

Inflammation (high serum CRP) and malnutrition (low serum albumin) in patients on haemodialysis are significantly associated with carotid atherosclerosis. Inflammation was more prevalent in the malnourished patients than in those with normal nutritional status.

Effects of Carnitine on Nutritional Parameters in Patients with Chronic Kidney Disease: An Updated Systematic Review and Meta-Analysis

Protein energy malnutrition is a common problem in patients with chronic kidney disease (CKD). Scattered reports indicate that supplementation of Carnitine may improve patients' clinical symptoms, with significant improvement in nutritional parameters. This systematic review was done to document the evidences of Carnitine effects in nutritional status of CKD patients. Peer-reviewed RCTs on Carnitine administration at any dose in CKD patients with at least four weeks of follow-up were including in the meta-analysis. Online databases (PubMed/Medline, ISI Web of Science, Embase, and Scopus) were searched to October 2017 using selected MeSH terms related to the study topic. Data was extracted independently by two reviewers using a standard form and then cross-checked. Statistical analyses were carried out with Comprehensive Meta-analysis software. Data are presented as standard mean difference (SMD) and 95% confidence interval (CI). According to the predefined criteria, a total of 14 randomized controlled clinical trials were included and screened for data extraction by two reviewers, separately. The preliminary results extracted from meta-analysis have shown that Carnitine can significantly increase the levels of albumin (SMD: -0.861; 95% CI: -1.321, -0.402), total protein (SMD: -0.418; 95% CI: -0.695, -0.141), total cholesterol (SMD: -0.350; 95% CI: -0.564, -0.135), LDL cholesterol (SMD: -0.362; 95% CI: -0.551, -0.173), transferrin (SMD: -1.465; 95% CI: -1.822, -1.108), and hemoglobin (SMD: -0.525; 95% CI: -0.732, -0.318); however there were no conclusive effects of Carnitine on body weight (SMD: -0.057; 95% CI: -0.404, 0.291) and BMI (SMD: -0.567; 95% CI: -1.548, 0.415), in pooled analyses. The results of this meta-analysis showed that there are considerable useful pieces of evidence so far about the effect of Carnitine on nutritional factors; however, there is still doubt about some evidences with this regard. It seems necessary to carry out clinical trials with stronger designs to evaluate the impact of these primary outcomes on the patients' clinical conditions. Having this evidences, the potential role of Carnitine in improving malnutrition consequences in CKD patients would be clearly defined.

Prevalence of Periodontitis in Patients Undergoing Hemodialysis: a Case Control Study

Objectives:

To assess the prevalence of periodontal disease among patients undergoing renal dialysis.

Methods:

Sixty hemodialysis patients (30 males, 30 females) with a mean age of 44.4±9.5 years comprised the study group. Periodontal parameters such as plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment level (CAL) were measured in these patients and 60 age and sex-matched control subjects. The data was tabulated and analyzed.

Results:

The mean duration of dialysis was 5.50±3.02 years. The plaque index (PI) bleeding on probing (BOP), Periodontal probing depth (PPD) and clinical attachment level (CAL) were significantly higher in patients undergoing hemodialysis than in control subjects. The mean clinical attachment level was significantly higher among the dialysis patients (2.78±0.83 mm) than the control subjects (1.97±0.53 mm). The plaque index and bleeding on probing also showed a similar pattern in patients undergoing hemodialysis compared to control patients. The prevalence and severity of periodontal disease seems to be higher in patients undergoing dialysis.

Conclusion:

From the observations of this study, it can be concluded that patients undergoing hemodialysis are more prone to periodontal diseases. Further studies with a larger population and a comparison with the duration of dialysis may further substantiate the current findings.

Repeated Combined Chemotherapy with Cisplatin Lowers Carnitine Levels in Gastric Cancer Patients

BACKGROUND/AIMS

Carnitine plays an important role in the metabolism of fatty acids. It has also been reported that the administration of anticancer drugs may lead to reductions in serum carnitine levels due to decreased activity of organic cation transporter novel 2, which plays a role in the reabsorption of carnitine in the tubules of the kidney. We therefore studied the change in carnitine levels when chemotherapy was administered repeatedly to patients with gastric cancer.

METHODS

Ten patients with upper gastrointestinal cancer were enrolled in this study between December 2014 and August 2015. All patients were administered chemotherapy consisting of TS-1 and cisplatin every 3 weeks: 3 received it as adjuvant therapy post resection, the remaining 7 received it as treatment for unresectable tumors. Before the start of each chemotherapy cycle, serum was collected.

RESULTS

The mean total carnitine level was 54.5 ± 13.7 μmol/L prior to commencing chemotherapy; it was 46.7 ± 13.5 and 41.4 ± 14.8 μmol/L at the second and third cycles respectively. The total carnitine level was decreased in a statistically significant manner (p = 0.0039). The serum level of total protein and cholinesterase was also decreased significantly (p = 0.0218 and p = 0.0418).

CONCLUSION

Carnitine levels decreased during repeated chemotherapy in patients with gastric cancer, and they are associated with the nutritional status.

Effects of L-carnitine supplementation on lipid profiles in patients with coronary artery disease

Background

L-carnitine (LC) plays an important physiologic role in lipid metabolism. To date, no clinical study has been performed to examine the effect of LC supplementation on the lipid status of coronary artery disease (CAD) patients. The aim of this study was to investigate the lipid lowering effects of LC supplementation (1000 mg/d) in CAD patients.

Methods

CAD patients were identified by cardiac catheterization as having at least 50 % stenosis of one major coronary artery. Forty-seven subjects were recruited and randomly assigned to the placebo (n = 24) and to the LC (n = 23) groups. The intervention was administered for 12 weeks. The levels of LC, lipid profiles, and antioxidant enzyme activity (superoxide dismutase, SOD) were measured.

Results

The subjects in the LC group had significantly higher SOD activity (20.7 ± 4.2 versus 13.1 ± 2.9 U/mg of protein, P < 0.01), high density lipoprotein-cholesterol (1.34 ± 0.42 vs. 1.16 ± 0.24 mmol/L, HDL-C, P = 0.03), and apolipoprotein-A1 (Apo-A1, 1.24 ± 0.18 vs. 1.12 ± 0.13 g/L, P = 0.02) than those in the placebo group at week 12. Triglyceride (TG) level was slightly significantly reduced (1.40 ± 0.74 vs. 1.35 ± 0.62 mmol/L, P = 0.06) and the level of LC was negatively correlated with TG and apolipoprotein-B (Apo-B), and positively correlated with HDL-C and Apo-A1 after LC supplementation. Additionally, SOD activity was significantly negatively correlated with lipid profiles (total cholesterol, TG, and Apo-B) after supplementation.

Conclusion

LC supplementation at a dose of 1000 mg/d showed significantly increased in HDL-C and Apo-A1 levels and a slight decrease in TG levels but no other changes in other lipids in CAD patients, and this lipid-lowering effect may be related to its antioxidant ability. Further studies should be conducted to define an optimal dose of LC for lipid-lowering in patients with CAD.

Trial registration

Clinical Trials.gov Identifier: NCT01819701

Mitochondria: a new therapeutic target in chronic kidney disease

Cellular metabolic changes during chronic kidney disease (CKD) may induce higher production of oxygen radicals that play a significant role in the progression of renal damage and in the onset of important comorbidities. This condition seems to be in part related to dysfunctional mitochondria that cause an increased electron "leakage" from the respiratory chain during oxidative phosphorylation with a consequent generation of reactive oxygen species (ROS). ROS are highly active molecules that may oxidize proteins, lipids and nucleic acids with a consequent damage of cells and tissues. To mitigate this mitochondria-related functional impairment, a variety of agents (including endogenous and food derived antioxidants, natural plants extracts, mitochondria-targeted molecules) combined with conventional therapies could be employed. However, although the anti-oxidant properties of these substances are well known, their use in clinical practice has been only partially investigated. Additionally, for their correct utilization is extremely important to understand their effects, to identify the correct target of intervention and to minimize adverse effects. Therefore, in this manuscript, we reviewed the characteristics of the available mitochondria-targeted anti-oxidant compounds that could be employed routinely in our nephrology, internal medicine and renal transplant centers. Nevertheless, large clinical trials are needed to provide more definitive information about their use and to assess their overall efficacy or toxicity.

Effect of L-carnitine Supplementation on Circulating C-reactive Protein Levels: A Systematic Review and Meta-Analysis

Background

C-reactive protein (CRP) has been proposed as a risk marker and risk factor of cardiovascular disease. There have been a number of clinical reports suggesting that supplementation with L-carnitine can modulate systemic inflammation and lower circulating CRP concentrations, but the results have not been consistent.

Methods

A comprehensive literature search in Medline, Scopus and Cochrane Central Register of Controlled Trials was performed in December 2012 to identify clinical trials investigating the impact of oral L-carnitine supplementation on serum/plasma CRP concentration. A random effect method was used to calculate the combined effect size.

Results

Six studies comprising 541 cases and 546 controls met the inclusion criteria. Meta-analysis of included trials revealed a significant reduction of circulating CRP concentrations in subjects under L-carnitine intervention compared to the control treatment. The calculated combined weighted mean reduction in CRP concentrations was −0.39 mg/L [95% CI (−0.62 – −0.16)]. This effect size estimate was found to be robust and remained unaffected by the removal of each single study.

Conclusions

The overall findings of the present meta-analysis support the clinically relevant benefit of L-carnitine supplementation in lowering the circulating levels of CRP.

Effects of levocarnitine on brachial-ankle pulse wave velocity in hemodialysis patients: a randomized controlled trial

Background and Aims: Atherosclerotic cardiovascular disease is the most common cause of mortality in patients with end-stage kidney disease. Chronic kidney disease patients often exhibit a deficiency in l-carnitine due to loss during hemodialysis (HD). We studied the effects of l-carnitine supplementation on brachial-ankle pulse wave velocity (baPWV), a marker of atherosclerosis, in HD patients. Methods: This was a prospective, open-label, randomized, parallel controlled, multi-center trial testing the anti-atherosclerotic efficacy of oral l-carnitine administration (20 mg/kg/day). HD patients (n = 176, mean age, 67.2 ± 10.3 years old; mean duration of HD, 54 ± 51 months) with plasma free l-carnitine deficiency (<40 μmol/L) were randomly assigned to the oral l-carnitine group (n = 88) or control group (n = 88) and monitored during 12 months of treatment. Results: There were no significant differences in baseline clinical variables between the l-carnitine and control groups. l-carnitine supplementation for 12 months significantly increased total, free, and acyl carnitine levels, and reduced the acyl/free carnitine ratio. The baPWV value decreased from 2085 ± 478 cm/s at baseline to 1972 ± 440 cm/s after six months (p < 0.05) to 1933 ± 363 cm/s after 12 months (p < 0.001) of l-carnitine administration, while no significant changes in baPWV were observed in the control group. Baseline baPWV was the only factor significantly correlated with the decrease in baPWV. Conclusions: l-carnitine supplementation significantly reduced baPWV in HD patients. l-carnitine may be a novel therapeutic strategy for preventing the progression of atherosclerotic cardiovascular disease.

Antiinflammatory effects of L-carnitine supplementation (1000 mg/d) in coronary artery disease patients

OBJECTIVE

Inflammation mediators have been recognized as risk factors for the pathogenesis of coronary artery disease (CAD). The purpose of this study was to investigate the effect of L-carnitine supplementation (LC, 1000 mg/d) on inflammation markers in patients with CAD.

METHODS

We enrolled 47 patients with CAD in the study. The patients with CAD were identified by cardiac catheterization as having <50% stenosis of one major coronary artery. The patients were randomly assigned to the placebo (n = 24) and LC (n = 23) groups and the intervention was administered for 12 wk. The levels of LC, antioxidant status (malondialdehyde and antioxidant enzymes activities), and inflammation markers (C-reactive protein [CRP], interleukin [IL]-6, and tumor necrosis factor [TNF]-α) were measured.

RESULTS

Thirty-nine participants completed the study (19 placebo; 20 LC). After LC supplementation, the levels of inflammation markers were significantly reduced compared with the baseline (CRP, P < 0.01; IL-6, P = 0.03; TNF-α, P = 0.07) and those in the placebo group (CRP, P < 0.05; IL-6, P = 0.04; TNF-α, P = 0.03). The levels of inflammation markers were significantly negatively correlated with the levels of LC and antioxidant enzymes activities (P < 0.05).

CONCLUSIONS

We suggest that LC supplementation, due to its antioxidant effects, may have potential utility to reduce inflammation in CAD.

L-Carnitine supplementation for adults with end-stage kidney disease requiring maintenance hemodialysis: a systematic review and meta-analysis

BACKGROUND

A previous meta-analysis indicated that l-carnitine significantly increased hemoglobin and decreased the required erythropoietin dose in maintenance hemodialysis patients.

OBJECTIVE

An updated systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to reevaluate effects of l-carnitine.

DESIGN

The Cochrane Library, PubMed, and EMBASE databases (31 December 2012) were searched to identify RCTs that investigated effects of l-carnitine in adults with end-stage kidney disease that required maintenance hemodialysis.

RESULTS

Forty-nine RCTs (1734 participants) were included. l-Carnitine significantly decreased serum low-density lipoprotein (LDL) (mean difference: -5.82 mg/dL; 95% CI: -11.61, -0.04 mg/dL) and C-reactive protein (CRP) (-3.65 mg/L; -6.19, -1.12 mg/L). There were no significant differences in triglycerides (-0.89 mg/dL; -29.32, 27.53 mg/dL), cholesterol (0.14 mg/dL; -6.15, 6.42 mg/dL), high-density lipoprotein (1.13 mg/dL; -2.44, 4.70 mg/dL), hemoglobin (0.68 g/dL; 0.14, 1.50 g/dL), hematocrit (2.04%; -1.39, 5.48%), albumin (1.65 g/L; -0.22, 3.51 g/L), or the required erythropoietin dose (-0.76 KU/wk; -1.75, 0.23 KU/wk). No adverse effects were reported.

CONCLUSIONS

This meta-analysis failed to confirm the previous findings regarding the effects of l-carnitine on hemoglobin and the erythropoietin dose but showed that l-carnitine significantly decreased serum LDL and CRP. The extent of the decrease in LDL was not clinically relevant, whereas the significant decrease in CRP was both statistically and clinically relevant. However, the relevance of decrease in CRP with hard endpoints such as all-cause mortality and cardiovascular complications still remains to be clarified.

Effect of L-carnitine therapy on patients in maintenance hemodialysis: a systematic review and meta-analysis

BACKGROUND

L-Carnitine has been used as adjuvant therapy in hemodialysis (HD) patients for many years. However, there is controversy whether L-carnitine supplementation is beneficial. Therefore we performed a meta-analysis of randomized controlled trials (RCTs) to assess the effect of L-carnitine on HD patients.

METHODS

RCTs of L-carnitine versus placebo for HD patients were searched from Medline, EMBASE and the Cochrane Central Register of Controlled Trials. We screened relevant studies according to predefined inclusion and exclusion criteria, and performed meta-analyses using Revman 5.1 software.

RESULTS

Meta-analysis showed L-carnitine could not increase the total score of 36-item Short-Form Health Survey Questionnaire (SF-36) (SMD 0.76, 95 % CI -0.13 to 1.65, P = 0.09), and L-carnitine therapy did not improve serum C-reactive protein (SMD -0.37, 95 % CI -0.88 to 0.14, P = 0.16), oxidized low-density lipoprotein (SMD 0.04, 95 % CI -0.43 to 0.50, P = 0.87), albumin (SMD 0.25, 95 % CI -0.31 to 0.81, P = 0.38;), hemoglobin (SMD 0.23, 95 % CI -0.23 to 0.68, P = 0.33), cholesterol (SMD -0.24, 95 % CI -0.71 to 0.24, P = 0.33), triglycerides (SMD 0.02, 95 % CI -0.4 to 0.44, P = 0.91) or parathyroid hormone (SMD 0.21, 95 % CI -0.35 to 0.76, P = 0.46) levels.

CONCLUSIONS

There is no evidence that L-carnitine can improve the inflammation, oxidative stress, nutrition, anemia, dyslipidemia, hyperparathyroidism status or quality of life in HD patients. However, given methodological limitations and lack of hard endpoints, high-quality, long-term randomized trials are required to fully elucidate the clinical value of L-carnitine administration in hemodialysis patients.

Use of a computerized C-reactive protein (CRP) based sepsis evaluation in very low birth weight (VLBW) infants: a five-year experience

BACKGROUND

Serial C-reactive protein (CRP) values may be useful for decision-making regarding duration of antibiotics in neonates. However, established standard of practice for its use in preterm very low birth weight (<1500 g, VLBW) infants are lacking.

OBJECTIVE

Evaluate compliance with a CRP-guided computerized decision support (CDS) algorithm and compare characteristics and outcomes of compliant versus non-compliant cases. Measure correlation between CRPs and white blood count (WBC) indices.

METHODS

We examined 3 populations: 1) all preterm VLBW infants born at Vanderbilt 2006-2011 - we assessed provider compliance with CDS algorithm and measured relevant outcomes; 2) all patients with positive blood culture results admitted to the Vanderbilt NICU 2006-2012 - we tested the correlation between CRP and WBC results within 7 days of blood culture phlebotomy; 3) 1,000 randomly selected patients out of the 7,062 patients admitted to the NICU 2006-2012 - we correlated time-associated CRP values and absolute neutrophil counts.

RESULTS

Of 636 VLBW infants in cohort 1), 569 (89%) received empiric antibiotics for suspected early-onset sepsis. In 409 infants (72%) the CDS algorithm was followed; antibiotics were discontinued ≤48 hours in 311 (55%) with normal serial CRPs and continued in 98 (17%) with positive CRPs, resulting in significant reduction in antibiotic exposure (p<0.001) without increase in complications or subsequent infections. One hundred sixty (28%) were considered non-compliant because antibiotics were continued beyond 48 hours despite negative serial CRPs and blood cultures. Serial CRPs remained negative in 38 (12%) of 308 blood culture-positive infants from cohort 2, but only 4 patients had clinically probable sepsis with single organisms and no immunodeficiency besides extreme prematurity. Leukopenia of any cell type was not linked with CRPs in cohorts 2 and 3.

CONCLUSIONS

CDS/CRP-guided antibiotic use is safe and effective in culture-negative VLBW infants. CRP results are not affected by low WBC indices.

L-carnitine supplementation in dialysis: treatment in quest of disease

L-Carnitine (LC) administration has been recommended for specific indications in dialysis patients, including epoetin-resistant anemia, intradialytic hypotension, cardiomyopathy, fatigue, muscle weakness, and exercise performance; it may ameliorate insulin resistance, inflammation, and protein wasting. Use of LC for anemia and intradialytic hypotension has been approved for reimbursement by the Centers for Medicare and Medicaid Services. Yet, the data to support these recommendations are inadequate and have not been bolstered over several decades. LC administration continues to appeal to nephrologists because its use in dialysis patients has an attractive rationale, it addresses problems that persist despite dialysis, it is safe, and the existing literature does not refute its use. Nevertheless, definitive trials to justify LC administration have not been conducted and are increasingly unlikely to be funded. In an era of shrinking resources and bundling of dialysis services, the use of LC in dialysis patients will, appropriately, diminish.

L-carnitine treatment in incident hemodialysis patients: the multicenter, randomized, double-blinded, placebo-controlled CARNIDIAL trial

BACKGROUND

L-carnitine levels decrease rapidly and steadily with duration of hemodialysis, and carnitine depletion can impair response to recombinant human erythropoietin (rHuEPO). The study hypothesis was that L-carnitine supplementation during the first year of hemodialysis would improve this response.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

From October 2006 through March 2010, this multicenter, randomized, double-blinded study assigned 92 incident hemodialysis patients to receive placebo or 1 g of intravenous L-carnitine after each dialysis session for 1 year. The primary outcome measure compared the groups for rHuEPO resistance index (EPO-RI), defined as weekly rHuEPO doses (IU/kg body weight divided by hemoglobin level) (g/dl).

RESULTS

In the L-carnitine group, carnitine concentration increased from a mean ± SD of 79 ± 51 µmol/L to 258 ± 137 µmol/L; in the placebo group, it declined from 68 ± 25 µmol/L to 53 ± 24 µmol/L (interaction group × time, P<0.001). Carnitine deficiency affected about 30% of the patients in the placebo group during the study period. EPO-RI varied from 15.8 ± 11.3 to 9.5 ± 5.8 IU/kg per g/dl in the placebo group and from 20.6 ± 12.8 to 15.6 ± 15.9 IU/kg per g/dl in the L-carnitine group, for a mean variation of -3.94 ± 12.5 IU/kg per g/dl and -2.98 ± 15.5 IU/kg per g/dl, respectively (P=0.7). After adjustment for baseline characteristics, the EPO-RI course was similar in each group (difference between groups, P=0.10; interaction group × time, P=0.9).

CONCLUSIONS

Carnitine levels decrease by about 11% ± 33% during the first year of hemodialysis. Treatment of incident hemodialysis patients with L-carnitine does not improve their response to rHuEPO.

Effects of Oral L-Carnitine Supplementation on Lipid Profile, Anemia, and Quality of Life in Chronic Renal Disease Patients under Hemodialysis: A Randomized, Double-Blinded, Placebo-Controlled Trial

In patients on maintenance hemodialysis several factors reduce the body stored carnitine which could lead to dyslipidemia, anemia, and general health in these patients. We evaluated the effect of oral L-carnitine supplementation on lipid profiles, anemia, and quality of life (QOL) in hemodialysis patients. In a randomized, double-blinded, placebo-controlled trial, end-stage renal disease (ESRD) patients on hemodialysis received either L-carnitine 1 g/d (n = 24) or placebo (27 patients) for 16 weeks. At the end of the study, there was a significant decrease in triglyceride (-31.1 ± 38.7 mg/dL, P = 0.001) and a significant increase in HDL (3.7 ± 2.8 mg/dL, P < 0.001) levels in the carnitine group. Decrease in total cholesterol (-6.6 ± 16.0 mg/dL, P = 0.075) and increase in hemoglobin (0.7 ± 1.7 g/dL, P = 0.081) concentrations in the carnitine group were not significant. There was no statistically significant changes in LDL in any group (P > 0.05). Erythropoietin dose was significantly decreased in both the carnitine (-4750 ± 5772 mg, P = 0.001) and the placebo group (-2000 ± 4296 mg, P < 0.05). No improvement was observed in QOL scores of two groups. In ESRD patients under maintenance hemodialysis, oral L-carnitine supplementation may reduce triglyceride and cholesterol and increase HDL and hemoglobin and subsequently reduce needed erythropoietin dose without effect on QOL.

L carnitine in hemodialysis patients

Carnitine, 3-hydroxy-4-trimethylaminobutyrate, a small, water soluble molecule that is essential for mitochondrial fatty acid oxidation, is significantly reduced in hemodialysis patients. Uremia-induced carnitine deficiency, which is magnified by dialysis, is associated with symptoms or clinical problems such as anemia hyporesponsive to erythropoietin, cardiovascular diseases, and muscle weakness. This review examines studies dealing with the different clinical aspects of chronic renal failure patients in which carnitine deficiency may play a role and has also examined the studies, which have evaluated the effect of carnitine deficiency treatment. The reports reviewed in this study, including those more recent from our laboratory, have provided data suggesting that chronic renal failure and particularly hemodialysis patients can benefit from carnitine treatment in particular for renal anemia, insulin sensitivity, and protein catabolism. On the other hand, the heterogeneous clinical response to carnitine therapy in dialysis patients, reported by other studies, and the lack of large-scale randomized trials are the rationale for the reluctance regarding a widespread use of carnitine supplements in dialysis patients. Well-designed randomized clinical trials are therefore required to fully address the potentially important carnitine treatment in dialysis patients.

L-Carnitine induces recovery of liver lipid metabolism in cancer cachexia

Cancer cachexia causes metabolic alterations with a marked effect on hepatic lipid metabolism. L-Carnitine modulates lipid metabolism and its supplementation has been proposed as a therapeutic strategy in many diseases. In the present study, the effects of L-carnitine supplementation on gene expression and on liver lipid metabolism-related proteins was investigated in cachectic tumour-bearing rats. Wistar rats were assigned to receive 1 g/kg of L-carnitine or saline. After 14 days, supplemented and control animals were assigned to a control (N), control supplemented with L-carnitine (CN), tumour-bearing Walker 256 carcinosarcoma (TB) and tumour-bearing supplemented with L-carnitine (CTB) group. The mRNA expression of carnitine palmitoyltransferase I and II (CPT I and II), microsomal triglyceride transfer protein (MTP), liver fatty acid-binding protein (L-FABP), fatty acid translocase (FAT/CD36), peroxisome proliferator-activated receptor-alpha (PPAR-alpha) and organic cation transporter 2 (OCTN2) was assessed, and the maximal activity of CPT I and II in the liver measured, along with plasma and liver triacylglycerol content. The gene expression of MTP, and CPT I catalytic activity were reduced in TB, who also showed increased liver (150%) and plasma (3.3-fold) triacylglycerol content. L-Carnitine supplementation was able to restore these parameters back to control values (p<0.05). These data show that L-carnitine preserves hepatic lipid metabolism in tumour-bearing animals, suggesting its supplementation to be of potential interest in cachexia.

l-carnitine and cancer cachexia: Clinical and experimental aspects

Cancer cachexia is a multifaceted syndrome characterized, among many symptoms, by extensive muscle wasting. Chronic systemic inflammation, partly triggered and sustained by cytokines, as well as increased oxidative stress contributes to the pathogenesis of this complex metabolic disorder. l-carnitine plays a central role in the metabolism of fatty acids and shows important antioxidant and anti-inflammatory properties. Systemic carnitine depletion has been described in several diseases, and it is characterized by fatigue, muscle weakness, and decreased tolerance to metabolic stress. In cachectic cancer patients, low serum carnitine levels have been reported, and this change has been suggested to play an important contributory role in the development of cachexia. Based on these data, carnitine supplementation has been tested in preliminary studies concerning human cachexia, resulting in improved fatigue and quality of life. We present here a review of clinical and experimental evidence regarding the use of carnitine supplementation in the management of cancer cachexia.

Mechanistic contribution of carnitine deficiency to geriatric frailty

Frailty is a geriatric syndrome characterized by muscle weakness, sarcopenia, and fatigue, and is associated with several adverse health outcomes, including disability. Design of therapeutic interventions for geriatric frailty has been challenging and may be because of inadequate understanding of its biological underpinnings. Carnitine is important for energy production in skeletal muscles and there seems to be a negative correlation between advancing age and muscle carnitine levels. Carnitine deficiency may therefore contribute to geriatric frailty. Age-associated carnitine deficiency from a variety of etiologies, including organic cation transporter (OCTN2) mutation and carnitine palmitoyltransferase II (CPT) deficiency, may potentially explain the relationship between carnitine-associated mitochondrial dysfunction and geriatric frailty. Development of therapeutic agents capable of prevention or reversal of carnitine deficiency in older adults may minimize the occurrence of frailty in geriatric populations.

Multiple antioxidants and L-arginine modulate inflammation and dyslipidemia in chronic renal failure rats

The kidney is an important source of L-arginine, the endogenous precursor of nitric oxide (NO). Surgical problems requiring extensive renal mass reduction (RMR) decrease renal NO production, leading to multiple hemodynamic and homeostatic disorders manifested by hypertension, oxidative stress, and increased inflammatory cytokines. Using the RMR model of chronic renal failure (CRF), we assessed the effects of twelve weeks' administration of L-arginine and/or a mixture of antioxidants (L-carnitine, catechin, vitamins E and C) on plasma cytokines, soluble intercellular adhesion molecule-1 (sICAM-1), nitrate and nitrites (NO(2)/NO(3)), lipid profile, blood pressure, and renal function. CRF rats showed increased plasma IL-1 alpha, IL1-beta, IL-6, TNF-alpha, and sICAM-1 levels and decreased anti-inflammatory cytokines IL-4 and 10 levels, hypertension, and dyslipidemia. L-arginine treatment improved kidney functions, decreased systolic blood pressure, and decreased inflammatory cytokines levels. Antioxidants administration decreased inflammatory cytokines and sICAM-1 levels and increased IL-4 levels. Combined use of both L-arginine and the antioxidant mixture were very effective in their tendency to recover normal values of kidney functions, plasma cytokines, sICAM-1, blood pressure, NO(2)/NO(3), cholesterol, and triglycerides concentrations. Indeed, the effects of L-arginine and the antioxidants on the reduction of proinflammatory cytokines may open new perspectives in the treatment of uremia.

The Impact of Pre-Dialytic Endurance Training on Nutritional Status and Quality of Life in Stable Hemodialysis Patients (Sawada Study)

BACKGROUND

Protein-energy malnutrition and decreased quality of life (QOL) are common in hemodialysis (HD) patients. Although several studies have proved that regular exercise has beneficial effects, few control studies have shown the effects of exercise training on the nutritional status and QOL in HD patients.

METHODS

Fifty-five HD patients were recruited, and 22 of them were trained to exercise on an ergometer prior to dialysis three times a week for one year. Serum albumin levels, creatinine generation rate (CGR), and the Short Form 36 were assessed as outcome measures.

RESULTS

The serum albumin levels and CGR increased in the training group compared with baseline. The QOL scores also increased in half of the physical health and mental health dimensions in the training group.

CONCLUSION

These observations suggest that low-dose, long-term pre-dialytic endurance training might reverse the poor clinical outcome by improving the nutritional status and QOL in HD patients.

Malnutrition and wasting in renal disease

PURPOSE OF REVIEW

Malnutrition and accelerated catabolism frequently complicate chronic kidney disease and end-stage renal disease. This review provides an update on the recent advances in the understanding of the mechanisms underlying protein-energy wasting, both in experimental and human models, and on the currently available therapeutic approaches.

RECENT FINDINGS

Increased levels of circulating cytokines, metabolic acidosis, oxidative stress and insulin resistance all appear to be variably implicated in muscle protein breakdown during end-stage renal disease and dialysis. The individual role of each component in the pathogenesis of chronic kidney disease-related wasting is still unclear, but recent clinical data show a positive relationship between inflammation and muscle protein catabolism as a major contributing factor.

SUMMARY

The basis for appropriate therapeutic approaches to protein-energy wasting in chronic kidney disease and end-stage renal disease relies entirely on the understanding of its pathophysiology. Our knowledge of the pathogenesis of malnutrition and hypercatabolism in renal disease is still limited and mostly based on experimental data, but the currently available evidence suggests that multimodal preventive and therapeutic strategies should be entertained.

Advances in Carnitine in Chronic Uremia

Carnitine is a conditionally essential metabolite that plays a critical role in cell physiology. Carnitine is necessary for fatty acid transport to sites of beta-oxidation in the mitochondria, where it helps to prevent organic acid accumulation. Because of these key regulatory functions, carnitine represents a crucial determinant of mitochondrial energy metabolism, whose deficiency may lead to metabolic and clinical disturbances. Loss of carnitine through dialytic membranes occurs in maintenance hemodialysis, resulting in potential carnitine depletion and relative increments of esterified carnitine forms. Carnitine supplementation has been shown to counteract such alterations and may be associated with clinical benefit. In particular, carnitine supplementation in patients on hemodialysis may enhance response to erythropoietin, resulting in improved hematologic status. Carnitine was also reported to improve exercise tolerance and intradialytic symptoms. Carnitine supplementation may enhance insulin resistance, inflammatory and antioxidant status, protein balance, lipid profile, and cardiac function. Carnitine administration can be useful for selected patients on dialysis who do not adequately respond to standard therapy.

Antimyopathic effects of carnitine and nicotine

PURPOSE OF REVIEW

The clinical course of most chronic diseases is associated with declined energy intake and nutrient-resistant progressive myopathy, characterized by accelerated proteolysis and impaired function. This anorexia/cachexia syndrome leads to deterioration of quality of life, and increased morbidity and mortality. The clinical efficacy of currently available therapeutic strategies is limited and more effective treatments are needed.

RECENT FINDINGS

Chronic systemic inflammation, triggered and sustained by cytokines, and increased oxidative stress contribute to the pathogenesis of the anorexia/cachexia syndrome. Carnitine and nicotine have recently been tested as immunomodulating and antioxidant agents. In particular, carnitine supplementation has been shown to reduce chronic inflammation and oxidative stress in hemodialysis patients and, in cancer patients, yielding to reduced fatigue and improved outcome. Nicotine is able to induce the anti-inflammatory activity of the vagus nerve. In animal models of sepsis and cancer, the nicotine-induced supplementation resulted in better protection of nutritional status and improved survival.

SUMMARY

In the continuous effort to develop more efficacious strategies against the anorexia/cachexia syndrome, carnitine and nicotine may represent a further therapeutic tool. More clinical studies are needed, however, before their use can be routinely suggested.

Nutritional Status in Hemodialysis Patients: Options for On-Line Convective Treatment

Although hemodialysis (HD) has improved the life expectancy of patients with end-stage renal disease (ESRD), uremic patients continue to experience high morbidity and mortality. Two of the most important risk factors for morbidity and mortality are protein-energy malnutrition (PEM) and inflammation. The causes for PEM in ESRD are numerous. The use of materials for dialysis, especially of the dialyzer membrane, is reported as one of the recognized causes for chronic inflammation in hemodialysis. We performed a 6-month prospective study examining the influence of on-line predilution hemodiafiltration on the inflammatory and nutritional status in a population of male hemodialysis patients using ultrapure dialysis fluid and polyamide dialyzers. We evaluated serum C-reactive protein, albumin, and transferrin and some nutritional parameters such as body mass index (BMI), phase angle (phi), fatty mass (FM), and free fatty mass (FFM) using bioelectrical impedance (BIA). Results showed significant amelioration of BMI and the re-equilibrium of the acute phase protein after on-line predilution hemodiafiltration. These results support the hypothesis that on-line predilution hemodiafiltration, as convective extracorporeal treatment, may be used to treat malnourished hemodialysis patients and to prevent malnutrition in the ESRD patient at risk for malnutrition.

Debate Forum: Levocarnitine Therapy Is Rational and Justified in Selected Dialysis Patients

Carnitine is a metabolic cofactor which is essential for normal fatty acid metabolism. Patients with chronic kidney disease on dialysis have been shown both to suffer from disordered fatty acid metabolism and to have a significant deficiency in plasma and tissue carnitine. Aberrant fatty acid metabolism has been associated with a number of cellular abnormalities such as increased mitochondrial permeability (a promoter of apoptosis), insulin resistance, and enhanced generation of free radicals. These cellular abnormalities have, in turn, been correlated with pathological clinical conditions common in dialysis patients including cardiomyopathy with attendant hypotension and resistance to the therapeutic effect of recombinant human erythropoietin (EPO). In 1999, the Food and Drug Administration approved levocarnitine injection for the prevention and treatment of carnitine deficiency in patients on dialysis based on documentation of free plasma carnitine levels in dialysis patients similar to other serious carnitine deficiency states for which treatment was required. Data analysis performed by expert panels convened by both the American Association of Kidney Patients and, subsequently, the National Kidney Foundation recommended a trial of levocarnitine therapy for specific subsets of dialysis patients including those with EPO resistance, dialysis-related hypotension, cardiomyopathy and muscle weakness. In 2003, the Centers for Medicare and Medicaid services convened a Medical Advisory Committee which established reimbursement on a national level for carnitine-deficient dialysis patients who had either dialysis-related hypotension or EPO resistance. Recently, a correlation between reductions in hospitalization rates of dialysis patients receiving levocarnitine therapy has been demonstrated in a large retrospective study. Despite data-based recommendations and national reimbursement, only a small minority of dialysis patients have been prescribed a therapeutic trial of levocarnitine. Whereas the reasons for the reluctance of nephrologists to prescribe this therapeutic trial are unclear, possible explanations include a lack of appreciation of the pivotal role played by carnitine in cellular metabolism and the strength of evidence for a substantial deficiency of carnitine in dialysis patients, an underestimation of the prognostic import of EPO resistance and dialysis-related hypotension, inadequate dissemination of the clinical trial data supporting the use of levocarnitine in dialysis patients, and the heterogeneous clinical response of dialysis patients to levocarnitine therapy. Difficulties in documenting both initial eligibility and evidence of improvement as a result of therapy may also be a contributing factor. This paper discusses the biological role of carnitine and its particular relevance to dialysis patients. Clinical trial data concerning an effect of therapy on EPO resistance and dialysis-related hypotension are summarized along with a discussion of the logic behind the use of levocarnitine in dialysis. Finally, the difficulties posed by a reimbursement policy based on clinical as opposed to laboratory endpoints and a heterogeneous response to therapy are addressed.