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British Journal of Sports Medicine Apr 2017To conduct a systematic review and meta-analysis of the evidence on the effects of β-alanine supplementation on exercise capacity and performance. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To conduct a systematic review and meta-analysis of the evidence on the effects of β-alanine supplementation on exercise capacity and performance.
DESIGN
This study was designed in accordance with PRISMA guidelines. A 3-level mixed effects model was employed to model effect sizes and account for dependencies within data.
DATA SOURCES
3 databases (PubMed, Google Scholar, Web of Science) were searched using a number of terms ('β-alanine' and 'Beta-alanine' combined with 'supplementation', 'exercise', 'training', 'athlete', 'performance' and 'carnosine').
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Inclusion/exclusion criteria limited articles to double-blinded, placebo-controlled studies investigating the effects of β-alanine supplementation on an exercise measure. All healthy participant populations were considered, while supplementation protocols were restricted to chronic ingestion. Cross-over designs were excluded due to the long washout period for skeletal muscle carnosine following supplementation. A single outcome measure was extracted for each exercise protocol and converted to effect sizes for meta-analyses.
RESULTS
40 individual studies employing 65 different exercise protocols and totalling 70 exercise measures in 1461 participants were included in the analyses. A significant overall effect size of 0.18 (95% CI 0.08 to 0.28) was shown. Meta-regression demonstrated that exercise duration significantly (p=0.004) moderated effect sizes. Subgroup analyses also identified the type of exercise as a significant (p=0.013) moderator of effect sizes within an exercise time frame of 0.5-10 min with greater effect sizes for exercise capacity (0.4998 (95% CI 0.246 to 0.753)) versus performance (0.1078 (95% CI -0.201 to 0.416)). There was no moderating effect of training status (p=0.559), intermittent or continuous exercise (p=0.436) or total amount of β-alanine ingested (p=0.438). Co-supplementation with sodium bicarbonate resulted in the largest effect size when compared with placebo (0.43 (95% CI 0.22 to 0.64)).
SUMMARY/CONCLUSIONS
β-alanine had a significant overall effect while subgroup analyses revealed a number of modifying factors. These data allow individuals to make informed decisions as to the likelihood of an ergogenic effect with β-alanine supplementation based on their chosen exercise modality.
Topics: Athletic Performance; Carnosine; Dietary Supplements; Exercise; Humans; Muscle, Skeletal; Randomized Controlled Trials as Topic; beta-Alanine
PubMed: 27797728
DOI: 10.1136/bjsports-2016-096396 -
JAMA Jun 2015Nonalcoholic fatty liver disease and its subtype nonalcoholic steatohepatitis affect approximately 30% and 5%, respectively, of the US population. In patients with... (Review)
Review
IMPORTANCE
Nonalcoholic fatty liver disease and its subtype nonalcoholic steatohepatitis affect approximately 30% and 5%, respectively, of the US population. In patients with nonalcoholic steatohepatitis, half of deaths are due to cardiovascular disease and malignancy, yet awareness of this remains low. Cirrhosis, the third leading cause of death in patients with nonalcoholic fatty liver disease, is predicted to become the most common indication for liver transplantation.
OBJECTIVES
To illustrate how to identify patients with nonalcoholic fatty liver disease at greatest risk of nonalcoholic steatohepatitis and cirrhosis; to discuss the role and limitations of current diagnostics and liver biopsy to diagnose nonalcoholic steatohepatitis; and to provide an outline for the management of patients across the spectrum of nonalcoholic fatty liver disease.
EVIDENCE REVIEW
PubMed was queried for published articles through February 28, 2015, using the search terms NAFLD and cirrhosis, mortality, biomarkers, and treatment. A total of 88 references were selected, including 16 randomized clinical trials, 44 cohort or case-control studies, 6 population-based studies, and 7 meta-analyses.
FINDINGS
Sixty-six percent of patients older than 50 years with diabetes or obesity are thought to have nonalcoholic steatohepatitis with advanced fibrosis. Even though the ability to identify the nonalcoholic steatohepatitis subtype within those with nonalcoholic fatty liver disease still requires liver biopsy, biomarkers to detect advanced fibrosis are increasingly reliable. Lifestyle modification is the foundation of treatment for patients with nonalcoholic steatosis. Available treatments with proven benefit include vitamin E, pioglitazone, and obeticholic acid; however, the effect size is modest (<50%) and none is approved by the US Food and Drug Administration. The association between nonalcoholic steatohepatitis and cardiovascular disease is clear, though causality remains to be proven in well-controlled prospective studies. The incidence of nonalcoholic fatty liver disease-related hepatocellular carcinoma is increasing and up to 50% of cases may occur in the absence of cirrhosis.
CONCLUSIONS AND RELEVANCE
Between 75 million and 100 million individuals in the United States are estimated to have nonalcoholic fatty liver disease and its potential morbidity extends beyond the liver. It is important that primary care physicians, endocrinologists, and other specialists be aware of the scope and long-term effects of the disease. Early identification of patients with nonalcoholic steatohepatitis may help improve patient outcomes through treatment intervention, including transplantation for those with decompensated cirrhosis.
Topics: Alanine Transaminase; Biomarkers; Biopsy; Diabetes Complications; Diet Therapy; Exercise; Fatty Liver; Humans; Liver; Non-alcoholic Fatty Liver Disease; Obesity; Pioglitazone; Risk Factors; Thiazolidinediones; Vitamin E
PubMed: 26057287
DOI: 10.1001/jama.2015.5370 -
Nutrients Jun 2022Nutritional ergogenic aids (NEAs) are substances included within the group of sports supplements. Although they are widely consumed by athletes, evidence-based analysis... (Meta-Analysis)
Meta-Analysis Review
Nutritional ergogenic aids (NEAs) are substances included within the group of sports supplements. Although they are widely consumed by athletes, evidence-based analysis is required to support training outcomes or competitive performance in specific disciplines. Combat sports have a predominant use of anaerobic metabolism as a source of energy, reaching peak exertion or sustained effort for very short periods of time. In this context, the use of certain NEAs could help athletes to improve their performance in those specific combat skills (i.e., the number of attacks, throws and hits; jump height; and grip strength, among others) as well as in general physical aspects (time to exhaustion [TTE], power, fatigue perception, heart rate, use of anaerobic metabolism, etc.). Medline/PubMed, Scopus and EBSCO were searched from their inception to May 2022 for randomised controlled trials (RCTs). Out of 677 articles found, 55 met the predefined inclusion criteria. Among all the studied NEAs, caffeine (5-10 mg/kg) showed strong evidence for its use in combat sports to enhance the use of glycolytic pathways for energy production during high-intensity actions due to a greater production of and tolerance to blood lactate levels. In this regard, abilities including the number of attacks, reaction time, handgrip strength, power and TTE, among others, were improved. Buffering supplements such as sodium bicarbonate, sodium citrate and beta-alanine may have a promising role in high and intermittent exertion during combat, but more studies are needed in grappling combat sports to confirm their efficacy during sustained isometric exertion. Other NEAs, including creatine, beetroot juice or glycerol, need further investigation to strengthen the evidence for performance enhancement in combat sports. Caffeine is the only NEA that has shown strong evidence for performance enhancement in combat sports.
Topics: Athletes; Athletic Performance; Caffeine; Dietary Supplements; Humans; Performance-Enhancing Substances; Sports Nutritional Physiological Phenomena
PubMed: 35807770
DOI: 10.3390/nu14132588 -
Clinical Microbiology and Infection :... Sep 2022The benefits of remdesivir in the treatment of hospitalized patients with COVID-19 remain debated with the National Institutes of Health and the World Health... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The benefits of remdesivir in the treatment of hospitalized patients with COVID-19 remain debated with the National Institutes of Health and the World Health Organization providing contradictory recommendations for and against use.
OBJECTIVES
To evaluate the role of remdesivir for hospitalized inpatients as a function of oxygen requirements.
DATA SOURCES
Beginning with our prior systematic review, we searched MEDLINE using PubMed from 15 January 2021 through 5 May 2022.
STUDY ELIGIBILITY CRITERIA
Randomised controlled trials; all languages.
PARTICIPANTS
All hospitalized adults with COVID-19.
INTERVENTIONS
Remdesivir, in comparison to either placebo, or standard of care.
ASSESSMENT OF RISK OF BIAS
We used the ROB-2 criteria.
METHODS OF DATA SYNTHESIS
The primary outcome was mortality, stratified by oxygen use (none, supplemental oxygen without mechanical ventilation, and mechanical ventilation). We conducted a frequentist random effects meta-analysis on the risk ratio scale and, to contextualize the probabilistic benefits, we also performed a Bayesian random effects meta-analysis on the risk difference scale. A ≥1% absolute risk reduction was considered clinically important.
RESULTS
We identified eight randomized trials, totaling 10 751 participants. The risk ratio for mortality comparing remdesivir vs. control was 0.77 (95% CI, 0.5-1.19) in the patients who did not require supplemental oxygen; 0.89 (95% CI, 0.79-0.99) for nonventilated patients requiring oxygen; and 1.08 (95% CI, 0.88-1.31) in the setting of mechanical ventilation. Using neutral priors, the probabilities that remdesivir reduces mortality were 76.8%, 93.8%, and 14.7%, respectively. The probability that remdesivir reduced mortality by ≥ 1% was 77.4% for nonventilated patients requiring oxygen.
CONCLUSIONS
Based on this meta-analysis, there is a high probability that remdesivir reduces mortality for nonventilated patients with COVID-19 requiring supplemental oxygen therapy. Treatment guidelines should be re-evaluated.
Topics: Adenosine Monophosphate; Adult; Alanine; Bayes Theorem; Humans; Oxygen; SARS-CoV-2; United States; COVID-19 Drug Treatment
PubMed: 35598856
DOI: 10.1016/j.cmi.2022.04.018 -
Nutrients Jun 2020Rowing is a high-intensity sport requiring a high level of aerobic and anaerobic capacity. Although good nutrition is essential for successful performance in a rowing... (Meta-Analysis)
Meta-Analysis
Rowing is a high-intensity sport requiring a high level of aerobic and anaerobic capacity. Although good nutrition is essential for successful performance in a rowing competition, its significance is not sufficiently established. This review aimed to provide nutritional strategies to optimize performance and recovery in rowing athletes based on a literature review. Following the guidelines given in the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA), we performed web searches using online databases (Pubmed, Web of Science, Wiley Online Library, ACS Publications, and SciFinder). Typically, a rowing competition involves a 6-8-min high-intensity exercise on a 2000-m course. The energy required for the exercise is supplied by muscle-stored glycogens, which are derived from carbohydrates. Therefore, rowing athletes can plan their carbohydrate consumption based on the intensity, duration, and type of training they undergo. For effective and safe performance enhancement, rowing athletes can take supplements such as β-alanine, caffeine, β-hydroxy-β-methylbutyric acid (HMB), and beetroot juice (nitrate). An athlete may consume carbohydrate-rich foods or use a carbohydrate mouth rinse. Recovery nutrition is also very important to minimize the risk of injury or unexplained underperformance syndrome (UUPS) from overuse. It must take into account refueling (carbohydrate), rehydration (fluid), and repair (protein). As lightweight rowing athletes often attempt acute weight loss by limiting food and fluid intake to qualify for a competition, they require personalized nutritional strategies and plans based on factors such as their goals and environment. Training and competition performance can be maximized by including nutritional strategies in training plans.
Topics: Athletes; Athletic Performance; Caffeine; Dietary Carbohydrates; Dietary Supplements; Energy Metabolism; Female; Fluid Therapy; Glycogen; Humans; Male; Muscle, Skeletal; Nitrates; Nutritional Physiological Phenomena; Nutritional Requirements; Physical Conditioning, Human; Water Sports; beta-Alanine
PubMed: 32516908
DOI: 10.3390/nu12061685 -
Journal of the International Society of... 2022Previous studies have suggested that beta-alanine supplementation may benefit exercise performance, but current evidence regarding its effects on body composition... (Meta-Analysis)
Meta-Analysis
PURPOSE
Previous studies have suggested that beta-alanine supplementation may benefit exercise performance, but current evidence regarding its effects on body composition remains unclear. This systematic review and meta-analysis aimed to investigate the effects of beta-alanine supplementation on body composition indices.
METHODS
Online databases, including PubMed/Medline, Scopus, Web of Science, and Embase, were searched up to April 2021 to retrieve randomized controlled trials (RCTs), which examined the effect of beta-alanine supplementation on body composition indices. Meta-analyses were carried out using a random-effects model. The I index was used to assess the heterogeneity of RCTs.
RESULTS
Among the initial 1413 studies that were identified from electronic databases search, 20 studies involving 492 participants were eligible. Pooled effect size from 20 studies indicated that beta-alanine supplementation has no effect on body mass (WMD: -0.15 kg; 95% CI: -0.78 to 0.47; = 0.631, I = 0.0%, = 0.998), fat mass (FM) (WMD: -0.24 kg; 95% CI: -1.16 to 0.68; = 0.612, I = 0.0%, = 0.969), body fat percentage (BFP) (WMD: -0.06%; 95% CI: -0.53 to 0.40; = 0.782, I = 0.0%, = 0.936), and fat-free mass (FFM) (WMD: 0.05 kg; 95% CI: -0.71 to 0.82; = 0.889, I = 0.0%, = 0.912). Subgroup analyses based on exercise type (resistance training [RT], endurance training [ET], and combined training [CT]), study duration (<8 and ≥8 weeks), and beta-alanine dosage (<6 and ≥6 g/d) demonstrated similar results. Certainty of evidence across outcomes ranged from low to moderate.
CONCLUSIONS
This meta-analysis study suggests that beta-alanine supplementation is unlikely to improve body composition indices regardless of supplementation dosage and its combination with exercise training. No studies have examined the effect of beta-alanine combined with both diet and exercise on body composition changes as the primary variable. Therefore, future studies examining the effect of the combination of beta-alanine supplementation with a hypocaloric diet and exercise programs are warranted.
Topics: Body Composition; Dietary Supplements; Exercise; Humans; beta-Alanine
PubMed: 35813845
DOI: 10.1080/15502783.2022.2079384 -
Reumatologia Clinica 2019To assess the efficacy and side effects of methotrexate and leflunomide in patients with rheumatoid arthritis (RA) as the first disease-modifying antirheumatic drug... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To assess the efficacy and side effects of methotrexate and leflunomide in patients with rheumatoid arthritis (RA) as the first disease-modifying antirheumatic drug (DMARD).
METHODS
We performed a systematic review and meta-analysis of clinical studies that included patients who took methotrexate, leflunomide, placebo or another DMARD for RA treatment. A systematic review yielded 1971 articles from databases; once completely reviewed, 73 trials that completed inclusion criteria were selected. In structured workshops for discussion and assessment of each article, 6 could be meta-analyzed for the primary and secondary outcomes: achievement of American College of Rheumatology (ACR) 20 and its core set components; and change of serum C-reactive protein (CRP) levels, Health Assessment Questionnaire Disability Index (HAQ-Di), liver enzyme aspartate transaminase/alanine transaminase ratio, new gastrointestinal (GI) side effects and infections.
RESULTS
A total of 1984 patients were included: 986 took leflunomide and 998 methotrexate. The probability of achieving ACR 20 had an odds ratio (OR) of 0.88 (95% confidence interval [CI] 0.74, 1.06) with a trend toward favoring methotrexate; reduction of the swollen joint count was greater for methotrexate: mean difference=0.82 (95%CI 0.24, 1.39); tender joint count, physician global assessment, HAQ-Di, and serum CRP levels revealed no significant difference between groups. Increased liver enzymes were more frequent in the leflunomide group, OR=0.38 (95%CI 0.27, 0.53), and new GI complaints were more common with methotrexate (OR=1.44; 95%CI 1.17, 1.79). There was no difference in the incidence of non-severe infections.
CONCLUSION
Leflunomide used as the first DMARD in RA seemed to be as efficacious as methotrexate; only the reduction of swollen joint count was more marked for methotrexate. Leflunomide was linked to a greater increase in liver enzymes, but there were fewer GI complaints.
Topics: Alanine Transaminase; Anti-Inflammatory Agents, Non-Steroidal; Antirheumatic Agents; Arthritis, Rheumatoid; Aspartate Aminotransferases; C-Reactive Protein; Chemical and Drug Induced Liver Injury; Clinical Trials as Topic; Disability Evaluation; Drug Therapy, Combination; Gastrointestinal Diseases; Humans; Immunosuppressive Agents; Leflunomide; Methotrexate; Treatment Outcome; gamma-Glutamyltransferase
PubMed: 28867467
DOI: 10.1016/j.reuma.2017.07.020 -
Nutrients May 2023The effectiveness of the Mediterranean diet (MD) in non-alcoholic fatty liver disease (NAFLD) subjects has been evaluated in several randomized controlled trials (RCTs).... (Meta-Analysis)
Meta-Analysis Review
Does the Mediterranean Diet Have Any Effect on Lipid Profile, Central Obesity and Liver Enzymes in Non-Alcoholic Fatty Liver Disease (NAFLD) Subjects? A Systematic Review and Meta-Analysis of Randomized Control Trials.
The effectiveness of the Mediterranean diet (MD) in non-alcoholic fatty liver disease (NAFLD) subjects has been evaluated in several randomized controlled trials (RCTs). This systematic review and meta-analysis aimed to evaluate the overall effects of MD intervention in a cohort of NAFLD patients targeting specific markers such as central obesity, lipid profile, liver enzymes and fibrosis, and intrahepatic fat (IHF). Google Scholar, PubMed, and Scopus were explored to collect relevant studies from the last 10 years. RCTs with NAFLD subjects were included in this systematic review with a mean intervention duration from 6 weeks to 1 year, and different intervention strategies, mainly including energy restriction MD (normal or low glycaemic index), low-fat MD with increased monounsaturated and polyunsaturated fatty acids, and increased exercise expenditure. The outcomes measured in this meta-analysis were gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), total cholesterol (TC), waist circumference (WC), and liver fibrosis. Ten randomized controlled trials, which involved a total of 737 adults with NAFLD, were included. According to the results, the MD seems to decrease the liver stiffness (kPa) by -0.42 (CI95% -0.92, 0.09) ( = 0.10) and significantly reduce the TC by -0.46 mg/dl (CI95% -0.55, -0.38) ( = 0.001), while no significant findings were documented for liver enzymes and WC among patients with NAFLD. In conclusion, the MD might reduce indirect and direct outcomes linked with NAFLD severity, such as TC, liver fibrosis, and WC, although it is important to consider the variations across trials. Further RCTs are necessary to corroborate the findings obtained and provide further evidence on the role of the MD in the modulation of other disorders related to NAFLD.
Topics: Adult; Humans; Non-alcoholic Fatty Liver Disease; Obesity, Abdominal; Diet, Mediterranean; Obesity; Liver Cirrhosis; Alanine Transaminase; Lipids
PubMed: 37242133
DOI: 10.3390/nu15102250 -
Nutrients Aug 2020Beta-alanine supplementation (BA) has a positive impact on physical performance. However, evidence showing a benefit of this amino acid in aerobic-anaerobic transition... (Meta-Analysis)
Meta-Analysis
Beta-alanine supplementation (BA) has a positive impact on physical performance. However, evidence showing a benefit of this amino acid in aerobic-anaerobic transition zones is scarce and the results controversial. The aim of this systematic review and meta-analysis is to analyze the effects of BA supplementation on physical performance in aerobic-anaerobic transition zones. At the same time, the effect of different dosages and durations of BA supplementation were identified. The search was designed in accordance with the PRISMA guidelines for systematic reviews and meta-analyses and performed in Web of Science (WOS), Scopus, SPORTDiscus, PubMed, and MEDLINE between 2010 and 2020. The methodological quality and risk of bias were evaluated with the Cochrane Collaboration tool. The main variables were the Time Trial Test (TTT) and Time to Exhaustion (TTE) tests, the latter separated into the Limited Time Test (LTT) and Limited Distance Test (LDT). The analysis was carried out with a pooled standardized mean difference (SMD) through Hedges' g test (95% CI). Nineteen studies were included in the systematic review and meta-analysis, revealing a small effect for time in the TTT (SMD, -0.36; 95% CI, -0.87-0.16; I = 59%; = 0.010), a small effect for LTT (SMD, 0.25; 95% CI, -0.01-0.51; I = 0%; = 0.53), and a large effect for LDT (SMD, 4.27; 95% CI, -0.25-8.79; I = 94%; = 0.00001). BA supplementation showed small effects on physical performance in aerobic-anaerobic transition zones. Evidence on acute supplementation is scarce (one study); therefore, exploration of acute supplementation with different dosages and formats on physical performance in aerobic-anaerobic transition zones is needed.
Topics: Aerobiosis; Anaerobiosis; Dietary Supplements; Humans; Physical Functional Performance; Sports Nutritional Physiological Phenomena; beta-Alanine
PubMed: 32824885
DOI: 10.3390/nu12092490 -
Nutrients Dec 2022Most intervention studies investigating the effects of ergogenic aids (EAs) on sports performance have been carried out in the male population. Thus, the aim of this... (Meta-Analysis)
Meta-Analysis Review
Most intervention studies investigating the effects of ergogenic aids (EAs) on sports performance have been carried out in the male population. Thus, the aim of this systematic review and meta-analysis was to summarize the effects in the existing literature of EAs used by female athletes on performance. A literature research was conducted, and a descriptive analysis of the articles included in the systematic review was carried out. Meta-analyses could be performed on 32 of the included articles, evaluating performance in strength, sprint, and cardiovascular capacity. A random-effects model and the standardized mean differences (SMD) ± 95% confidence intervals (CI) were reported. The results showed that caffeine helped to improve jumping performance, isometric strength values, and the number of repetitions until failure. Caffeine and sodium phosphate helped to improve sprint performance. Aerobic tests could be improved with the use of taurine, caffeine, and beta-alanine. No conclusive effects of beetroot juice, polyphenols, or creatine in improving aerobic performance were shown. In terms of anaerobic variables, both caffeine and sodium phosphate could help to improve repeated sprint ability. More studies are needed in female athletes that measure the effects of different EAs on sports performance, such as beetroot juice, beta-alanine or sodium phosphate, as the studies to date are scarce and there are many types of EA that need to be further considered in this population, such as creatine and taurine.
Topics: Humans; Male; Female; Caffeine; Creatine; Athletic Performance; Athletes; Antioxidants; Performance-Enhancing Substances; beta-Alanine; Physical Functional Performance; Dietary Supplements
PubMed: 36615738
DOI: 10.3390/nu15010081