Acute Ketone Supplementation and Exercise Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

2020 ◽  
Vol 15 (3) ◽  
pp. 298-308 ◽  
Author(s):  
Pedro L. Valenzuela ◽  
Javier S. Morales ◽  
Adrián Castillo-García ◽  
Alejandro Lucia
Keyword(s):  
Randomized Controlled Trials ◽  
Exercise Performance ◽  
Perceived Exertion ◽  
Meta Analysis ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Controlled Trials ◽  
Glucose Levels ◽  
Randomized Controlled ◽  
Control Intervention

Purpose: To determine the acute effects of ketone supplementation on exercise performance (primary outcome) and physiological and perceptual responses to exercise (secondary outcomes). Methods: A systematic search was conducted in PubMed, Web of Science, and SPORTDiscus (since inception to July 21, 2019) to find randomized controlled trials assessing the effects of acute ketone supplementation compared with a drink containing no ketones (ie, control intervention). The standardized mean difference (Hedges g) between interventions and 95% confidence interval (CI) were computed using a random-effects model. Results: Thirteen studies met all inclusion criteria. No significant differences were observed between interventions for overall exercise performance (Hedges g = −0.05; 95% CI, −0.30 to 0.20; P = .68). Subanalyses revealed no differences between interventions when analyzing endurance time-trial performance (g = −0.04; 95% CI, −0.35 to 0.28; P = .82) or when assessing the separate effects of supplements containing ketone esters (g = −0.07; 95% CI, −0.38 to 0.24; P = .66) or salts (g = −0.02; 95% CI, −0.45 to 0.41; P = .93). All studies reported increases in plasma ketone concentration after acute ketone supplementation, but no consistent effects were reported on the metabolic (plasma lactate and glucose levels), respiratory (respiratory exchange ratio, oxygen uptake, and ventilatory rate), cardiovascular (heart rate), or perceptual responses to exercise (rating of perceived exertion). Conclusions: The present findings suggest that ketone supplementation exerts no clear influence on exercise performance (from sprints to events lasting up to ∼50 min) or metabolic, respiratory, cardiovascular, or perceptual responses to exercise. More research is needed to elucidate if this strategy could provide ergogenic effects on other exercise types (eg, ultraendurance exercise).

Effect of quercetin supplementation on plasma lipid profiles, blood pressure, and glucose levels: a systematic review and meta-analysis

2020 ◽  
Vol 78 (8) ◽  
pp. 615-626 ◽  
Author(s):  
Haohai Huang ◽  
Dan Liao ◽  
Yong Dong ◽  
Rong Pu
Keyword(s):  
Randomized Controlled Trials ◽  
Meta Analysis ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
Lipid Profiles ◽  
Controlled Trials ◽  
Parallel Design ◽  
Glucose Levels ◽  
Randomized Controlled ◽  
Subgroup Analyses

Abstract Context Clinical trials examining the cardiovascular protective effects of quercetin in humans have reported conflicting results. Objective The aim of this systematic review was to summarize evidence of the effects of quercetin supplementation on plasma lipid profiles, blood pressure (BP), and glucose levels in humans by performing a meta-analysis of randomized controlled trials. Data Sources MEDLINE, Embase, and Scopus databases were searched electronically from their inception to July 2018 to identify randomized controlled trials that assessed the impact of quercetin on lipid profiles, BP, and glucose levels. Study Selection Randomized controlled trials assessing the effects of quercetin or a standardized quercetin-enriched extract on plasma lipid profiles, BP, and glucose levels in humans were eligible for inclusion. Data Extraction A random-effects model was used for data analysis. Continuous variables were expressed as weighted mean differences (WMDs) and 95%CIs. Subgroup analyses were conducted to explore possible influences of study characteristics. Sensitivity analyses were also performed, as were analyses of publication bias. Results Seventeen trials (n = 896 participants total) were included in the overall analysis. Pooled results showed that quercetin significantly lowered both systolic BP (WMD, −3.09 mmHg; 95%CI, −4.59 to −1.59; P = 0.0001) and diastolic BP (WMD, −2.86 mmHg; 95%CI, −5.09 to −0.63; P = 0.01). Neither lipid profiles nor glucose concentrations changed significantly. In subgroup analyses, significant changes in high-density lipoprotein cholesterol and triglycerides were observed in trials with a parallel design and in which participants consumed quercetin for 8 weeks or more. Conclusion Quercetin intake resulted in significantly decreased BP in humans. Moreover, participants who consumed quercetin for 8 weeks or more showed significantly changed levels of high-density lipoprotein cholesterol and triglycerides in trials with a parallel design.

A systematic review and meta-analysis of propionyl-l-carnitine effects on exercise performance in patients with claudication

2013 ◽  
Vol 18 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Eric P Brass ◽  
David Koster ◽  
William R Hiatt ◽  
Antonino Amato
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Randomized Controlled Trials ◽  
Exercise Performance ◽  
Meta Analysis ◽  
Phase Iii ◽  
Walking Distance ◽  
Controlled Trials ◽  
Primary Analysis ◽  
Randomized Controlled

Propionyl-l-carnitine (PLC) may improve exercise performance in patients with peripheral artery disease, but results from clinical trials have been inconsistent. The safety and efficacy of PLC for treatment of claudication was evaluated by a systematic review and meta-analysis of clinical trials for which data were available through September 2010. Eighty-five studies were identified, of which 13 were randomized controlled trials. Owing to database availability for the six phase III studies carried out with PLC (1 g orally, twice daily), a patient-level meta-analysis was conducted as the primary analysis. Treadmill performance data from these six studies were harmonized to peak walking distance (PWD) on a 7% grade at a speed of 3 km/hour. PLC ( n = 440) was associated with a net 16 meter improvement (95% CI, 8–20 meters) in PWD as compared with placebo ( n = 427) in the primary analysis ( p = 0.002). The effect of PLC was similar in subpopulations defined using clinical and demographic variables, with possible enhanced benefit in patients engaged in an exercise program or enrolled at study sites in Russia. The systematic review of the effect of PLCs on claudication identified seven additional randomized controlled trials for a total of 13 trials, which included 681 patients on placebo and 672 on PLC. This meta-analysis confirmed a 45 meter net improvement on PLC using a random-effects model. In conclusion, oral PLC is associated with a statistically significant increase in PWD in patients with claudication, which may be clinically relevant.

Interventions for suicide and self-injury: A meta-analysis of randomized controlled trials across nearly 50 years of research.

2020 ◽  
Vol 146 (12) ◽  
pp. 1117-1145
Author(s):  
Kathryn R. Fox ◽  
Xieyining Huang ◽  
Eleonora M. Guzmán ◽  
Kensie M. Funsch ◽  
Christine B. Cha ◽  
...  
Keyword(s):  
Randomized Controlled Trials ◽  
Meta Analysis ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
Self Injury
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