scholarly journals Starvation effects on nitrogen and carbon stable isotopes of animals: an insight from meta-analysis of fasting experiments

2017 ◽  
Vol 4 (8) ◽  
pp. 170633 ◽  
Author(s):  
Hideyuki Doi ◽  
Fumikazu Akamatsu ◽  
Angélica L. González
Keyword(s):  
Meta Analysis ◽  
Nitrogen Excretion ◽  
Carbon Stable Isotopes ◽  
Starvation Period ◽  
Fasting Period ◽  
Web Studies ◽  
Stable Isotopic ◽  
Starvation Effects ◽  
Underlying Mechanisms ◽  
Excretion Rates

Nitrogen and carbon stable isotopic compositions ( δ 15 N and δ 13 C) of consumers have been used for physiological and food web studies. Previous studies have shown δ 15 N and δ 13 C values are affected by several biological and environmental factors during starvation, but the generality of the effect of starvation on δ 15 N and δ 13 C values has not yet been tested. Here, we performed a meta-analysis to evaluate the effects of starvation on δ 15 N and δ 13 C values of consumers, and the underlying factors that may explain the observed variation. The δ 15 N and δ 13 C values were calculated as the differences between the final δ 15 N and δ 13 C values of consumers (post-starvation) and the pre-starvation values on each experiment. Our meta-analysis showed a large variation in the δ 15 N and δ 13 C values of consumers (δ 15 N range: –0.82 to 4.30‰; mean: 0.47‰ and δ 13 C range: –1.92 to 2.62‰; mean: 0.01‰). The δ 15 N values of most consumers increased along the length of the starvation period and were influenced by nitrogen excretion and thermoregulation types, probably because differences in nitrogen metabolism and thermoregulation affect nitrogen processing and excretion rates. None of our predictor variables accounted for the variation in δ 13 C values, which showed both increases and decreases due to fasting. Our findings suggest that starvation results in changes in consumer δ 15 N values which are mainly explained by the length of the fasting period and by nitrogen and energy metabolism, but the underlying mechanisms of the starvation effects on δ 13 C values seem to be more complex than previously thought.

scholarly journals 306 - Loneliness and mortality in older adults and the role of depression

2020 ◽  
Vol 32 (S1) ◽  
pp. 64-64
Author(s):  
T.J. Holwerda ◽  
D. Rhebergen ◽  
H.C. Comijs ◽  
J.J.M. Dekker ◽  
M.L. Stek
Keyword(s):  
Cardiovascular Disease ◽  
Older Adults ◽  
Mortality Risk ◽  
Meta Analysis ◽  
Clinical Perspective ◽  
Cross Sectional ◽  
Mediating Role ◽  
Underlying Mechanisms ◽  
Dexamethasone Suppression

Background:The prevalence of loneliness increases with age. The presence of loneliness in older adults has been found to be associated with health problems such as depression, decreased cognitive functioning, increases in systolic blood pressure and increased mortality. The underlying mechanisms of the higher mortality risk are largely unknown.Methods:Meta-analysis to investigate the present evidence for the associations between loneliness and mortality. Cross-sectional studies investigating the associations between loneliness and cardiovascular disease and between loneliness and cortisol in 378 depressed and 132 non-depressed older adults.Results:Loneliness appears to be associated with increased mortality, although when only studies are included that consider depression as a covariate, the association is not significant. Therefore it seems likely that depression plays a mediating role in the higher mortality risk.We did not find a significant association between loneliness and cardiovascular disease. In contrast, loneliness was significantly associated with lower cortisol output and decreased dexamethasone suppression.Discussion:The results and their implications for prevention and treatment will be discussed from a clinical perspective as well as a general health perspective. Is loneliness as potentially dangerous as depression?

319 Predicting Urinary Nitrogen Excretion from Milk Urea Nitrogen of Fresh Forage or Total Mixed Ration Fed Dairy Cows: A Meta-analysis

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 171-171
Author(s):  
Matthew R Beck ◽  
Cameron Marshall ◽  
Konagh Garrett ◽  
Andrew P Foote ◽  
Ronaldo Vibart ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Meta Analysis ◽  
Live Weight ◽  
Predictive Ability ◽  
Nitrogen Excretion ◽  
Good Precision ◽  
Urea Nitrogen ◽  
Total Mixed Ration ◽  
Milk Urea ◽  
Milk Urea Nitrogen

Abstract Urine nitrogen excretion (g/d; UN) represent a significant environmental impact for both confinement feeding and pastoral based dairy systems. It is difficult to measure UN directly due to animal handling and labor requirements, especially in forage based production systems. The currently available milk urea nitrogen (MUN) equations have been shown to overestimate UN excretion of grazing dairy cows compared with an equation using urinary creatinine and UN concentration, indicating that diet may alter the relationship between MUN and UN. This potential was explored using data retrieved (treatment means: n = 69 and 27 for fresh forage [FF] and total mixed ration [TMR] fed cattle, respectively) from the literature and new data obtained from dairy cows fed FF (n = 15) in metabolism crates was used to test the new equations. The TMR data from literature was further split into a training set (to develop the model; n = 53) and a test set (to validate the model; n = 16). There was an interaction for diet type (P < 0.01) where UN (g/d) = 0.023 × MUN (mg/dL) × live-weight (kg, LW) for TMR fed cattle, (similar to a pre-established equation); however, UN (g/d) = 0.015 × MUN × LW for FF fed cattle. For FF based equations, the New MUN equation and the creatinine equation showed good precision and accuracy (Lin’s CCC = 0.79 and 0.74, respectively) and adequate predictive ability (RMSEP = 29.8 and 35.9, respectively). The new MUN equation for TMR fed cattle showed excellent accuracy and precision (Lin’s CCC = 0.87) with good predictive ability (RMSEP = 24.3) for UN excretion (observed mean = 216.5 g/d). The new equations generated during this meta-analysis provide promising predictive ability of UN excretion, which can be used for management considerations, future research, and policy making.

scholarly journals Acetyl-L-Carnitine in Dementia and Other Cognitive Disorders: A Critical Update

Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1389 ◽  
Author(s):  
Manuela Pennisi ◽  
Giuseppe Lanza ◽  
Mariagiovanna Cantone ◽  
Emanuele D’Amico ◽  
Francesco Fisicaro ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Cognitive Disorders ◽  
Longitudinal Assessment ◽  
Cholinergic Activity ◽  
Homogeneous Sample ◽  
Mitochondrial Energy Metabolism ◽  
Clinical Scales ◽  
Slowing Down ◽  
Underlying Mechanisms

Several studies explored the effects of acetyl-L-carnitine (ALC) in dementia, suggesting a role in slowing down cognitive decline. Nevertheless, in 2003 a systematic review concluded there was insufficient evidence to recommend a clinical use, although a meta-analysis in the same year showed a significant advantage for ALC for clinical scales and psychometric tests. Since then, other studies have been published; however, a critical review is still lacking. We provide an update of the studies on ALC in primary and secondary dementia, highlighting the current limitations and translational implications. Overall, the role of ALC in dementia is still under debate. The underlying mechanisms may include restoring of cell membranes and synaptic functioning, enhancing cholinergic activity, promoting mitochondrial energy metabolism, protecting against toxins, and exerting neurotrophic effects. The effects of ALC on the gut–liver–brain axis seem to identify the category of patients in which the new insights contribute most to the mechanisms of action of ALC, likely being the liver metabolism and the improvement of hepatic detoxifying mechanisms the primary targets. In this framework, our research group has dealt with this topic, focusing on the ALC-related cross-talk mechanisms. Further studies with homogeneous sample and longitudinal assessment are needed before a systematic clinical application.

scholarly journals 17 Challenges and implications of feeding diets with excess concentrations of leucine to growing-finishing pigs

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 16-16
Author(s):  
Mike D Tokach ◽  
Henrique S Cemin ◽  
Hayden R Kerkaert ◽  
Jason C Woodworth ◽  
Steve S Dritz ◽  
...  
Keyword(s):  
Amino Acids ◽  
Blood Meal ◽  
Meta Analysis ◽  
Branched Chain Amino Acids ◽  
Nitrogen Excretion ◽  
Intact Protein ◽  
Future Research ◽  
Distillers Grains With Solubles ◽  
Diet Formulation ◽  
Branched Chain

Abstract Excess dietary leucine stimulates the key enzymes involved in branched-chain catabolism causing breakdown of all branched-chain amino acids, including isoleucine and valine. Branched-chain amino acids share a common brain transporter with other large neutral amino acids (LNAA). Excess levels of one of the LNAA increases brain uptake of that amino acid and decreases the uptake of the other LNAA, including tryptophan. Thus, excess leucine can impact the requirements for many amino acids. From a practical basis, this effect was first demonstrated with diets containing blood meal, but was thought to be of limited concern unless high blood meal diets were fed. Use of corn dried distillers grains with solubles (DDGS) or high protein DDGS in corn-based diets results in diets containing excess leucine. These high leucine levels are of limited concern if adequate levels of other branched-chain amino acids and LNAA are fed, which is often the case if the diet consists largely of intact protein sources. Feed grade amino acids, such as L-lysine, L-threonine, L-tryptophan, DL-methionine, L-valine, and L-isoleucine have been widely adopted as a means to lower nitrogen excretion and diet cost. Including these amino acids in diets containing corn products reduces dietary leucine; but the resulting diets are formulated near the requirement for the first 6 limiting amino acids, including valine, isoleucine, and tryptophan, while still being high in leucine. The excess leucine increases the requirements for valine, isoleucine, and possibly other LNAA, such as tryptophan and possibly others. The exact relationship between these amino acids and how to handle them in practical diet formulation is still being elucidated; however, recent meta-analysis and experimental data confirm the importance of these ratios and provide useful direction for future research.

scholarly journals Obsessive healthy eating and orthorexic eating tendencies in sport and exercise contexts: A systematic review and meta-analysis

2021 ◽  
Author(s):  
Jana Strahler ◽  
Hanna Wachten ◽  
Anett Mueller-Alcazar
Keyword(s):  
Systematic Review ◽  
Gender Differences ◽  
Healthy Eating ◽  
Meta Analysis ◽  
Group Analysis ◽  
Future Research ◽  
Exercise Behaviors ◽  
Sport And Exercise ◽  
Underlying Mechanisms ◽  
Meta Analyses

AbstractBackgroundOrthorexia Nervosa (ON) and exercise addiction (ExAdd) are two phenomena believed to overlap. We conducted a meta-analysis exploring the link between ON and (addictive) exercise behaviors.MethodsA systematic review of major databases and gray literature was carried out for studies reporting on ON and (addictive) exercise behaviors. Random effects meta-analyses were undertaken calculating correlations between ON and (addictive) exercise behaviors. A sub-group analysis investigated gender differences.ResultsTwenty-five studies with 10,134 participants (mean age = 25.21; 56.4% female) were included. Analyses showed a small overall correlation between ON and exercise (21 studies, r = 0.12, 95% CI |0.06–0.18|) and a medium overall correlation between ON and ExAdd (7 studies, r = 0.29, 95% CI |0.13–0.45|). Gender differences were negligible.ConclusionsOrthorexic eating correlated slightly and moderately with exercise and ExAdd, respectively, expressing some unique and shared variance of these behaviors. While this does not suggest ON and addictive exercising to be independent, it does not indicate substantial comorbidity. Future research should focus on clinical relevance, underlying mechanisms, vulnerability, and risk factors.

Nitrogen Excretion and Protein Consumption of the Bluegill Sunfish (Lepomis macrochirus)

1971 ◽  
Vol 28 (3) ◽  
pp. 449-451 ◽  
Author(s):  
J. Savitz
Keyword(s):  
Mathematical Description ◽  
Lepomis Macrochirus ◽  
Specific Dynamic Action ◽  
Nitrogen Excretion ◽  
Bluegill Sunfish ◽  
Protein Consumption ◽  
Dynamic Action ◽  
Excretion Rates

Nitrogen excretion rates increase with an increase in protein consumption levels. A mathematical description of this relation was formulated from the data. Estimates of the effect of specific dynamic action on nitrogen excretion were also calculated.

scholarly journals Effect of electroconvulsive therapy on hippocampal and amygdala volumes: systematic review and meta-analysis

2018 ◽  
Vol 212 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Akihiro Takamiya ◽  
Jun Ku Chung ◽  
Kuo-ching Liang ◽  
Ariel Graff-Guerrero ◽  
Masaru Mimura ◽  
...  
Keyword(s):  
Systematic Review ◽  
Electroconvulsive Therapy ◽  
Animal Studies ◽  
Brain Volume ◽  
Meta Analysis ◽  
Brain Structures ◽  
Volume Increase ◽  
Left Hippocampus ◽  
Before And After ◽  
Underlying Mechanisms

BackgroundElectroconvulsive therapy (ECT) is one of the most effective treatments for depression, although the underlying mechanisms remain unclear. Animal studies have shown that electroconvulsive shock induced neuroplastic changes in the hippocampus.AimsTo summarise volumetric magnetic resonance imaging studies investigating the effects of ECT on limbic brain structures.MethodA systematic review and meta-analysis was conducted to assess volumetric changes of each side of the hippocampus and amygdala before and after ECT. Standardised mean difference (SMD) was calculated.ResultsA total of 8 studies (n = 193) were selected for our analyses. Both right and left hippocampal and amygdala volumes increased after ECT. Meta-regression analyses revealed that age, percentage of those responding and percentage of those in remission were negatively associated with volume increases in the left hippocampus.ConclusionsECT increased brain volume in the limbic structures. The clinical relevance of volume increase needs further investigation.Declaration of interestNone.

scholarly journals Effect of Acute Caffeine Intake on the Fat Oxidation Rate during Exercise: A Systematic Review and Meta-Analysis

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3603
Author(s):  
Daniel Collado-Mateo ◽  
Ana Myriam Lavín-Pérez ◽  
Eugenio Merellano-Navarro ◽  
Juan Del Coso
Keyword(s):  
Systematic Review ◽  
Oxidation Rate ◽  
Meta Analysis ◽  
Fat Oxidation ◽  
Caffeine Intake ◽  
Fasting Period ◽  
Fitness Level ◽  
Recreational Athletes ◽  
Other Substances ◽  
Dose Response Effect

A number of previous investigations have been designed to determine the effect of acute caffeine intake on the rate of fat oxidation during exercise. However, these investigations have shown contradictory results due to the differences in the exercise protocols used or the co-ingestion of caffeine with other substances. Hence, to date, there is no consensus about the effect of caffeine on fat oxidation during exercise. The purpose of this study was to conduct a systematic review followed by a meta-analysis to establish the effect of acute intake of caffeine (ranging from 2 to 7 mg/kg of body mass) on the rate of fat oxidation during exercise. A total of 19 studies published between 1978 and 2020 were included, all of which employed crossover experimental designs in which the ingestion of caffeine was compared to a placebo. Studies were selected if the exercise intensity was consistent in the caffeine and placebo trials and if these were preceded by a fasting protocol. A subsequent meta-analysis was performed using the random effects model to calculate the standardized mean difference (SMD). The meta-analysis revealed that caffeine significantly (p = 0.008) increased the fat oxidation rate (SMD = 0.73; 95% CI = 0.19 to 1.27). This increment was consistent with a significant (p = 0.04) reduction of the respiratory exchange ratio (SMD = −0.33; 95% CI = −0.65 to −0.01) and a significant (p = 0.049) increase in the oxygen uptake (SMD = 0.23; 95% CI = 0.01 to 0.44). The results also showed that there was a dose–response effect of caffeine on the fat oxidation rate, indicating that more than 3.0 mg/kg is necessary to obtain a statistically significant effect of this stimulant on fat oxidation during exercise. Additionally, the ability of caffeine to enhance fat oxidation during exercise was higher in sedentary or untrained individuals than in trained and recreational athletes. In conclusion, pre-exercise intake of a moderate dose of caffeine may effectively increase fat utilization during aerobic exercise of submaximal intensity performed after a fasting period. However, the fitness level of the participant may modulate the magnitude of the effect of caffeine on fat oxidation during exercise.

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