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Jornal Brasileiro de Pneumologia :... 2019To evaluate the effects of high-intensity interval training (HIIT), in comparison with those of continuous exercise, on functional capacity and cardiovascular variables... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To evaluate the effects of high-intensity interval training (HIIT), in comparison with those of continuous exercise, on functional capacity and cardiovascular variables in patients with COPD, through a systematic review and meta-analysis of randomized controlled trials.
METHODS
We searched PubMed, the Physiotherapy Evidence Database, the Cochrane Central Register of Controlled Trials, and EMBASE, as well as performing hand searches, for articles published up through January of 2017. We included studies comparing exercise regimens of different intensities, in terms of their effects on functional capacity and cardiovascular variables in patients with COPD.
RESULTS
Of the 78 articles identified, 6 were included in the systematic review and meta-analysis. Maximal oxygen consumption (VO2max) did not differ significantly between HIIT and control interventions. That was true for relative VO2max (0.03 mL/kg/min; 95% CI: -3.05 to 3.10) and absolute VO2max (0.03 L/min, 95% CI: -0.02 to 0.08).
CONCLUSIONS
The effects of HIIT appear to be comparable to those of continuous exercise in relation to functional and cardiovascular responses. However, our findings should be interpreted with caution because the studies evaluated present a high risk of bias, which could have a direct influence on the results.
Topics: Exercise Therapy; High-Intensity Interval Training; Humans; Oxygen Consumption; Pulmonary Disease, Chronic Obstructive; Randomized Controlled Trials as Topic; Time Factors; Treatment Outcome
PubMed: 31576905
DOI: 10.1590/1806-3713/e20180011 -
Journal of Inherited Metabolic Disease Jan 2021Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an autosomal recessive condition due to a deficiency of α-aminoadipic semialdehyde dehydrogenase, which is a key enzyme...
Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an autosomal recessive condition due to a deficiency of α-aminoadipic semialdehyde dehydrogenase, which is a key enzyme in lysine oxidation. PDE-ALDH7A1 is a developmental and epileptic encephalopathy that was historically and empirically treated with pharmacologic doses of pyridoxine. Despite adequate seizure control, most patients with PDE-ALDH7A1 were reported to have developmental delay and intellectual disability. To improve outcome, a lysine-restricted diet and competitive inhibition of lysine transport through the use of pharmacologic doses of arginine have been recommended as an adjunct therapy. These lysine-reduction therapies have resulted in improved biochemical parameters and cognitive development in many but not all patients. The goal of these consensus guidelines is to re-evaluate and update the two previously published recommendations for diagnosis, treatment, and follow-up of patients with PDE-ALDH7A1. Members of the International PDE Consortium initiated evidence and consensus-based process to review previous recommendations, new research findings, and relevant clinical aspects of PDE-ALDH7A1. The guideline development group included pediatric neurologists, biochemical geneticists, clinical geneticists, laboratory scientists, and metabolic dieticians representing 29 institutions from 16 countries. Consensus guidelines for the diagnosis and management of patients with PDE-ALDH7A1 are provided.
Topics: Aldehyde Dehydrogenase; Arginine; Consensus; Dietary Supplements; Epilepsy; Humans; International Cooperation; Lysine; Pyridoxine
PubMed: 33200442
DOI: 10.1002/jimd.12332 -
Nutrients Nov 2022Time-restricted feeding (TRF) and Ramadan fasting (RF) have been recently associated with several health outcomes. However, it is not yet clear if they are superior to... (Review)
Review
Effects of Time-Restricted Feeding and Ramadan Fasting on Body Weight, Body Composition, Glucose Responses, and Insulin Resistance: A Systematic Review of Randomized Controlled Trials.
Time-restricted feeding (TRF) and Ramadan fasting (RF) have been recently associated with several health outcomes. However, it is not yet clear if they are superior to existing treatments in terms of glucose metabolism, insulin action, and weight loss. This review aims to summarize the current data on the effects of these regimes on body weight, body composition, and glycemia. An electronic search was conducted in PUBMED and SCOPUS databases up to August 2022. Twenty-four records met the inclusion criteria and underwent a risk-of-bias assessment. The main outcomes were: (a) TRF may result in moderate weight loss in individuals with overweight/obesity; when TRF is combined with caloric restriction, weight loss is >5% of the initial body weight, (b) 14 h of fasting may be as effective as 16 h in terms of weight loss, and (c) TRF may lead to improved insulin sensitivity and glycemic responses/variability throughout the day in individuals with overweight/obesity. Concerning RF, only two studies were available and thus, conclusions were not drawn. TRF may be an effective nutritional approach for weight loss, and the amelioration of glycemic control and insulin sensitivity in individuals with overweight/obesity. However, more long-term, well-designed studies are needed.
Topics: Humans; Blood Glucose; Body Composition; Body Weight; Fasting; Glucose; Insulin Resistance; Obesity; Overweight; Randomized Controlled Trials as Topic; Weight Loss
PubMed: 36432465
DOI: 10.3390/nu14224778 -
International Journal of Sports Medicine Apr 2022Training-intensity distribution (TID) is considered the key factor to optimize performance in endurance sports. This systematic review aimed to: I) characterize the TID...
Training-intensity distribution (TID) is considered the key factor to optimize performance in endurance sports. This systematic review aimed to: I) characterize the TID typically used by middle-and long-distance runners; II) compare the effect of different types of TID on endurance performance and its physiological determinants; III) determine the extent to which different TID quantification methods can calculate same TID outcomes from a given training program. The keywords and search strategy identified 20 articles in the research databases. These articles demonstrated differences in the quantification of the different training-intensity zones among quantification methods (i. e. session-rating of perceived exertion, heart rate, blood lactate, race pace, and running speed). The studies that used greater volumes of low-intensity training such as those characterized by pyramidal and polarized TID approaches, reported greater improvements in endurance performance than those which used a threshold TID. Thus, it seems that the combination of high-volume at low-intensity (≥ 70% of overall training volume) and low-volume at threshold and high-intensity interval training (≤ 30%) is necessary to optimize endurance training adaptations in middle-and long-distance runners. Moreover, monitoring training via multiple mechanisms that systematically encompasses objective and subjective TID quantification methods can help coaches/researches to make better decisions.
Topics: Endurance Training; High-Intensity Interval Training; Humans; Oxygen Consumption; Physical Endurance; Running
PubMed: 34749417
DOI: 10.1055/a-1559-3623 -
Advances in Nutrition (Bethesda, Md.) Dec 2021Although levodopa remains the most effective drug for symptomatic management of Parkinson's Disease (PD), treatment during advanced disease stages may raise...
Although levodopa remains the most effective drug for symptomatic management of Parkinson's Disease (PD), treatment during advanced disease stages may raise unpredictable motor fluctuations and other complications. Counteracting these complications with other pharmacological therapies may prompt a vicious circle of side effects, and here, nutritional therapy may have great potential. Knowledge about the role of diet in PD is emerging and multiple studies have investigated nutritional support specifically with respect to levodopa therapy. With this systematic review, we aim to give a comprehensive overview of dietary approaches to optimize levodopa treatment in PD. A systematic search was performed using the databases of PubMed and Scopus between January 1985 and September 2020. Nutritional interventions with the rationale to optimize levodopa therapy in human PD patients were eligible for this study and their quality was assessed with the Cochrane risk-of-bias tool. In total, we included 22 papers that addressed the effects of dietary proteins (n = 10), vitamins (n = 7), fiber (n = 2), soybeans (n = 1), caffeine (n = 1), and ketogenic diets (n = 1) on levodopa therapy. Interventions with protein redistribution diets (PRDs), dietary fiber, vitamin C, and caffeine improved levodopa absorption, thereby enhancing clinical response and reducing motor fluctuations. Furthermore, supplementation of vitamin B-12, vitamin B-6, and folic acid successfully reduced high homocysteine concentrations that emerged from levodopa metabolism and promoted many metabolic and clinical complications, such as neuropathology and osteoporosis. In conclusion, dietary interventions have the potential to optimize levodopa efficacy and control side effects. Nutrition that improves levodopa absorption, including PRDs, fiber, vitamin C, and caffeine, is specifically recommended when fluctuating clinical responses appear. Supplements of vitamin B-12, vitamin B-6, and folic acid are advised along with levodopa initiation to attenuate hyperhomocysteinemia, and importantly, their potential to treat consequent metabolic and clinical complications warrants future research.
Topics: Antiparkinson Agents; Diet; Humans; Levodopa; Parkinson Disease; Vitamin B 12
PubMed: 34113965
DOI: 10.1093/advances/nmab060 -
Sports Medicine (Auckland, N.Z.) Jan 2020Resistance training is well known to increase strength and lean body mass, and plays a key role in many female athletic and recreational training programs. Most females...
BACKGROUND
Resistance training is well known to increase strength and lean body mass, and plays a key role in many female athletic and recreational training programs. Most females train throughout their reproductive years when they are exposed to continuously changing female steroid hormone profiles due to the menstrual cycle or contraceptive use. Therefore, it is important to focus on how female hormones may affect resistance training responses.
OBJECTIVE
The aim of this systematic review is to identify and critically appraise current studies on the effect of the menstrual cycle and oral contraceptives on responses to resistance training.
METHODS
The electronic databases Embase, PubMed, SPORTDiscus and Web of Science were searched using a comprehensive list of relevant terms. Studies that investigated the effect of the menstrual cycle phase or oral contraceptive cycle on resistance training responses were included. Studies were also included if they compared resistance training responses between the natural menstrual cycle and oral contraceptive use, or if resistance training was adapted to the menstrual cycle phase or oral contraceptive phase. Studies were critically appraised with the McMasters Universities Critical Review Form for Quantitative Studies and relevant data were extracted.
RESULTS
Of 2007 articles found, 17 studies met the criteria and were included in this systematic review. The 17 included studies had a total of 418 participants with an age range of 18-38 years. One of the 17 studies found no significant differences in acute responses to a resistance training session over the natural menstrual cycle, while four studies did find changes. When assessing the differences in acute responses between the oral contraceptive and menstrual cycle groups, two studies reported oral contraceptives to have a positive influence, whilst four studies reported that oral contraceptive users had a delayed recovery, higher levels of markers of muscle damage, or both. For the responses to a resistance training program, three studies reported follicular phase-based training to be superior to luteal phase-based training or regular training, while one study reported no differences. In addition, one study reported no differences in strength development between oral contraceptive and menstrual cycle groups. One further study reported a greater increase in type I muscle fibre area and a trend toward a greater increase in muscle mass within low-androgenic oral contraceptive users compared with participants not taking hormonal contraceptives. Finally, one study investigated androgenicity of oral contraceptives and showed greater strength developments with high androgenic compared with anti-androgenic oral contraceptive use.
CONCLUSIONS
The reviewed articles reported conflicting findings, and were often limited by small participant numbers and methodological issues, but do appear to suggest female hormones may affect resistance training responses. The findings of this review highlight the need for further experimental studies on the effects of the menstrual cycle and oral contraceptives on acute and chronic responses to resistance training.
Topics: Body Composition; Contraceptives, Oral; Female; Humans; Menstrual Cycle; Muscle Strength; Resistance Training
PubMed: 31677121
DOI: 10.1007/s40279-019-01219-1 -
Human Reproduction Update Sep 2019A defining feature of sexual reproduction is the transmission of genomic information from both parents to the offspring. There is now compelling evidence that the...
BACKGROUND
A defining feature of sexual reproduction is the transmission of genomic information from both parents to the offspring. There is now compelling evidence that the inheritance of such genetic information is accompanied by additional epigenetic marks, or stable heritable information that is not accounted for by variations in DNA sequence. The reversible nature of epigenetic marks coupled with multiple rounds of epigenetic reprogramming that erase the majority of existing patterns have made the investigation of this phenomenon challenging. However, continual advances in molecular methods are allowing closer examination of the dynamic alterations to histone composition and DNA methylation patterns that accompany development and, in particular, how these modifications can occur in an individual's germline and be transmitted to the following generation. While the underlying mechanisms that permit this form of transgenerational inheritance remain unclear, it is increasingly apparent that a combination of genetic and epigenetic modifications plays major roles in determining the phenotypes of individuals and their offspring.
OBJECTIVE AND RATIONALE
Information pertaining to transgenerational inheritance was systematically reviewed focusing primarily on mammalian cells to the exclusion of inheritance in plants, due to inherent differences in the means by which information is transmitted between generations. The effects of environmental factors and biological processes on both epigenetic and genetic information were reviewed to determine their contribution to modulating inheritable phenotypes.
SEARCH METHODS
Articles indexed in PubMed were searched using keywords related to transgenerational inheritance, epigenetic modifications, paternal and maternal inheritable traits and environmental and biological factors influencing transgenerational modifications. We sought to clarify the role of epigenetic reprogramming events during the life cycle of mammals and provide a comprehensive review of how the genomic and epigenomic make-up of progenitors may determine the phenotype of its descendants.
OUTCOMES
We found strong evidence supporting the role of DNA methylation patterns, histone modifications and even non-protein-coding RNA in altering the epigenetic composition of individuals and producing stable epigenetic effects that were transmitted from parents to offspring, in both humans and rodent species. Multiple genomic domains and several histone modification sites were found to resist demethylation and endure genome-wide reprogramming events. Epigenetic modifications integrated into the genome of individuals were shown to modulate gene expression and activity at enhancer and promoter domains, while genetic mutations were shown to alter sequence availability for methylation and histone binding. Fundamentally, alterations to the nuclear composition of the germline in response to environmental factors, ageing, diet and toxicant exposure have the potential to become hereditably transmitted.
WIDER IMPLICATIONS
The environment influences the health and well-being of progeny by working through the germline to introduce spontaneous genetic mutations as well as a variety of epigenetic changes, including alterations in DNA methylation status and the post-translational modification of histones. In evolutionary terms, these changes create the phenotypic diversity that fuels the fires of natural selection. However, rather than being adaptive, such variation may also generate a plethora of pathological disease states ranging from dominant genetic disorders to neurological conditions, including spontaneous schizophrenia and autism.
Topics: Animals; Biological Evolution; DNA Methylation; Epigenesis, Genetic; Genome; Germ Cells; Heredity; Histone Code; Histones; Humans; Mammals; Mutation; Parents; Phenotype
PubMed: 31374565
DOI: 10.1093/humupd/dmz017 -
Journal of Investigative Medicine : the... Aug 2023The therapeutic response heterogeneity in acromegaly persists, despite the medical-surgical advances of recent years. Thus, personalized medicine implementation, which... (Review)
Review
The therapeutic response heterogeneity in acromegaly persists, despite the medical-surgical advances of recent years. Thus, personalized medicine implementation, which focuses on each patient, is justified. Metabolomics would decipher the molecular mechanisms underlying the therapeutic response heterogeneity. Identification of altered metabolic pathways would open new horizons in the therapeutic management of acromegaly. This research aimed to evaluate the metabolomic profile in acromegaly and metabolomics' contributions to understanding disease pathogenesis. A systematic review was carried out by querying four electronic databases and evaluating patients with acromegaly through metabolomic techniques. In all, 21 studies containing 362 patients were eligible. Choline, the ubiquitous metabolite identified in growth hormone (GH)-secreting pituitary adenomas (Pas) by in vivo magnetic resonance spectroscopy (MRS), negatively correlated with somatostatin receptors type 2 expression and positively correlated with magnetic resonance imaging T2 signal and Ki-67 index. Moreover, elevated choline and choline/creatine ratio differentiated between sparsely and densely granulated GH-secreting PAs. MRS detected low hepatic lipid content in active acromegaly, which increased after disease control. The panel of metabolites of acromegaly deciphered by mass spectrometry (MS)-based techniques mainly included amino acids (especially branched-chain amino acids and taurine), glyceric acid, and lipids. The most altered pathways in acromegaly were the metabolism of glucose (particularly the downregulation of the pentose phosphate pathway), linoleic acid, sphingolipids, glycerophospholipids, arginine/proline, and taurine/hypotaurine. Matrix-assisted laser desorption/ionization coupled with MS imaging confirmed the functional nature of GH-secreting PAs and accurately discriminated PAs from healthy pituitary tissue.
Topics: Humans; Acromegaly; Growth Hormone-Secreting Pituitary Adenoma; Magnetic Resonance Imaging; Metabolomics; Adenoma
PubMed: 37139720
DOI: 10.1177/10815589231169452 -
Nutrients Nov 2020A 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... (Meta-Analysis)
Meta-Analysis
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 ( = 0.008) increased the fat oxidation rate (SMD = 0.73; 95% CI = 0.19 to 1.27). This increment was consistent with a significant ( = 0.04) reduction of the respiratory exchange ratio (SMD = -0.33; 95% CI = -0.65 to -0.01) and a significant ( = 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.
Topics: Adipose Tissue; Caffeine; Central Nervous System Stimulants; Exercise; Humans; Lipid Metabolism
PubMed: 33255240
DOI: 10.3390/nu12123603 -
International Journal of Molecular... Nov 2022Fibroblast growth factor 21 is a pleiotropic hormone secreted mainly by the liver in response to metabolic and nutritional challenges. Physiologically, fibroblast growth... (Review)
Review
Fibroblast growth factor 21 is a pleiotropic hormone secreted mainly by the liver in response to metabolic and nutritional challenges. Physiologically, fibroblast growth factor 21 plays a key role in mediating the metabolic responses to fasting or starvation and acts as an important regulator of energy homeostasis, glucose and lipid metabolism, and insulin sensitivity, in part by its direct action on the central nervous system. Accordingly, pharmacological recombinant fibroblast growth factor 21 therapies have been shown to counteract obesity and its related metabolic disorders in both rodents and nonhuman primates. In this systematic review, we discuss how fibroblast growth factor 21 regulates metabolism and its interactions with the central nervous system. In addition, we also state our vision for possible therapeutic uses of this hepatic-brain axis.
Topics: Animals; Fibroblast Growth Factors; Liver; Insulin Resistance; Brain; Energy Metabolism
PubMed: 36362103
DOI: 10.3390/ijms232113318