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1.
PLoS One ; 15(7): e0236025, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32658929

RESUMO

BACKGROUND: The need to control for the potential influence of menstrual cycle phase on resting metabolism (RMR) places a burden on research participants who must self-report onset of menstruation and researchers who must schedule metabolic testing accordingly. PURPOSE: To systematically review and analyze existing research to determine the effect of menstrual cycle on RMR. METHODS: We searched PubMed, CINAHL, MEDLINE, SPORTDiscus, and Scopus databases using the search terms "menstrual cycle and metabolic rate" and "menstrual cycle and energy expenditure." Eligibility criteria were English language, single-group repeated measures design, and RMR as either a primary or secondary outcome. Risk of bias was assessed based on study sample, measurement, and control of confounders. Differences between the follicular and luteal phases of the menstrual cycle were analyzed using the standardized mean difference in effect size. RESULTS: Thirty English-language studies published between 1930 and December 2019 were included in the systematic review, and 26 studies involving 318 women were included in the meta-analysis. Overall, there was a small but significant effect favoring increased RMR in the luteal phase (ES = 0.33; 95% CI = 0.17, 0.49, p < 0.001). DISCUSSION: Limitations include risk of bias regarding measurement of both menstrual cycle and RMR. Sample sizes were small and studies did not report control of potential confounders. Sub-group analysis demonstrated that in more recent studies published since 2000, the effect of menstrual phase was reduced and not statistically significant (ES = 0.23; 95% CI = -0.00, 0.47; p = 0.055). Until larger and better designed studies are available, based on our current findings, researchers should be aware of the potential confounding influence of the menstrual cycle and control for it by testing consistently in one phase of the cycle when measuring RMR in pre-menopausal women.


Assuntos
Metabolismo Basal , Ciclo Menstrual , Descanso/fisiologia , Feminino , Humanos
2.
Oecologia ; 193(3): 547-556, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32638120

RESUMO

The pace-of-life syndrome describes covariation between life-history, behavioral and physiological traits; while, the emerging behavioral-bioenergetics theory proposes mechanistic links between those traits in a spatial-ecological context. However, little is known about the association between the limits to metabolic rate and spatial performance (i.e., mobility, home range size) in free-living individuals. Here we show, for the first time at the intra-specific level, that mobility traits increased with the aerobic exercise capacity ([Formula: see text]O2max) in a wild rodent, the bank vole (Myodes glareolus): [Formula: see text]O2max affected directly the movement intensity, which in turn affected home ranges. The results show that evolution of high [Formula: see text]O2max could be driven by selection for spatial performance traits, and corroborate one of the key assumptions of the behavioral-bioenergetics theory. However, the minimum maintenance metabolism, measured as the basal metabolic rate (BMR), was not correlated with movement intensity, and the direction of the BMR-home range correlation tended to change with age of the voles. The latter result indicates that testing the theory will be particularly challenging.


Assuntos
Arvicolinae , Comportamento de Retorno ao Território Vital , Animais , Metabolismo Basal , Metabolismo Energético , Fenótipo
3.
Sports Health ; 12(4): 382-389, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520660

RESUMO

BACKGROUND: Sport concussion (SC) causes an energy crisis in the brain by increasing energy demand, decreasing energy supply, and altering metabolic resources. Whole-body resting metabolic rate (RMR) is elevated after more severe brain injuries, but RMR changes are unknown after SC. The purpose of this study was to longitudinally examine energy-related changes in collegiate athletes after SC. HYPOTHESIS: RMR and energy consumption will increase acutely after SC and will return to control levels with recovery. STUDY DESIGN: Case-control study. LEVEL OF EVIDENCE: Level 4. METHODS: A total of 20 collegiate athletes with SC (mean age, 19.3 ± 1.08 years; mean height, 1.77 ± 0.11 m; mean weight, 79.6 ± 23.37 kg; 55% female) were compared with 20 matched controls (mean age, 20.8 ± 2.17 years; mean height, 1.77 ± 0.10 m; mean weight, 81.9 ± 23.45 kg; 55% female). RMR, percentage carbohydrate use (%CHO), and energy balance (EBal; ratio between caloric consumption and expenditure) were assessed 3 times: T1, ≤72 hours after SC; T2, 7 days after T1; and TF, after symptom resolution. A 2 × 2 × 3 (group × sex × time) multivariate analysis of variance assessed RMR, %CHO, and EBal. Changes in RMR, %CHO, and EBal (T1 to TF) were correlated with days to symptom-free and days to return to play in the concussed group. RESULTS: Women reported being symptom-free (median, 6 days; range, 3-10 days) sooner than men (median, 11 days; range, 7-16 days). RMR and %CHO did not differ across time between groups or for group × sex interaction. SC participants had higher EBal than controls at T1 (P = 0.016) and T2 (P = 0.010). In men with SC, increasing %CHO over time correlated with days to symptom-free (r = 0.735 and P = 0.038, respectively) and days to return to play (r = 0.829 and P = 0.021, respectively). CONCLUSION: Participants with SC were in energy surplus acutely after injury. Although women recovered more quickly than men, men had carbohydrate metabolism changes that correlated with recovery time. CLINICAL RELEVANCE: This pilot study shows that male and female student-athletes may have differing physiologic responses to SC and that there may be a role for dietary intervention to improve clinical outcomes after SC.


Assuntos
Traumatismos em Atletas/metabolismo , Metabolismo Basal , Concussão Encefálica/metabolismo , Carboidratos da Dieta/metabolismo , Ingestão de Energia , Metabolismo Energético , Feminino , Humanos , Masculino , Projetos Piloto , Fatores Sexuais , Adulto Jovem
4.
Nature ; 583(7814): 109-114, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32528181

RESUMO

Hibernating mammals actively lower their body temperature to reduce energy expenditure when facing food scarcity1. This ability to induce a hypometabolic state has evoked great interest owing to its potential medical benefits2,3. Here we show that a hypothalamic neuronal circuit in rodents induces a long-lasting hypothermic and hypometabolic state similar to hibernation. In this state, although body temperature and levels of oxygen consumption are kept very low, the ability to regulate metabolism still remains functional, as in hibernation4. There was no obvious damage to tissues and organs or abnormalities in behaviour after recovery from this state. Our findings could enable the development of a method to induce a hibernation-like state, which would have potential applications in non-hibernating mammalian species including humans.


Assuntos
Metabolismo Energético/fisiologia , Hibernação/fisiologia , Hipotálamo/citologia , Hipotálamo/fisiologia , Vias Neurais/citologia , Vias Neurais/fisiologia , Animais , Metabolismo Basal/fisiologia , Núcleo Hipotalâmico Dorsomedial/citologia , Núcleo Hipotalâmico Dorsomedial/fisiologia , Feminino , Neurônios GABAérgicos/metabolismo , Glutamina/metabolismo , Masculino , Camundongos , Consumo de Oxigênio/fisiologia
5.
Nat Commun ; 11(1): 2982, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32532969

RESUMO

Non-invasive and label-free calorimetry could become a disruptive technique to study single cell metabolic heat production without altering the cell behavior, but it is currently limited by insufficient sensitivity. Here, we demonstrate microfluidic single-cell calorimetry with 0.2-nW sensitivity, representing more than ten-fold enhancement over previous record, which is enabled by (i) a low-noise thermometry platform with ultralow long-term (10-h) temperature noise (80 µK) and (ii) a microfluidic channel-in-vacuum design allowing cell flow and nutrient delivery while maintaining a low thermal conductance of 2.5 µW K-1. Using Tetrahymena thermophila as an example, we demonstrate on-chip single-cell calorimetry measurement with metabolic heat rates ranging from 1 to 4 nW, which are found to correlate well with the cell size. Finally, we perform real-time monitoring of metabolic rate stimulation by introducing a mitochondrial uncoupling agent to the microchannel, enabling determination of the spare respiratory capacity of the cells.


Assuntos
Calorimetria/métodos , Técnicas Analíticas Microfluídicas/métodos , Microfluídica/métodos , Análise de Célula Única/métodos , Temperatura , Tetrahymena thermophila/metabolismo , Metabolismo Basal , Calorimetria/instrumentação , Microfluídica/instrumentação , Mitocôndrias/metabolismo , Consumo de Oxigênio , Análise de Célula Única/instrumentação , Tetrahymena thermophila/citologia , Condutividade Térmica
6.
Nat Commun ; 11(1): 2983, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32532993

RESUMO

Calorimetry has been widely used in metabolic studies, but direct measurements from individual small biological model organisms such as C. elegans or isolated single cells have been limited by poor sensitivity of existing techniques and difficulties in resolving very small heat outputs. Here, by careful thermal engineering, we developed a robust, highly sensitive and bio-compatible calorimetric platform that features a resolution of ~270 pW-more than a 500-fold improvement over the most sensitive calorimeter previously used for measuring the metabolic heat output of C. elegans. Using this calorimeter, we demonstrate time-resolved metabolic measurements of single C. elegans worms from larval to adult stages. Further, we show that the metabolic output is significantly lower in long-lived C. elegans daf-2 mutants. These demonstrations clearly highlight the broad potential of this tool for studying the role of metabolism in disease, development and aging of small model organisms and single cells.


Assuntos
Caenorhabditis elegans/metabolismo , Calorimetria/métodos , Análise de Célula Única/métodos , Temperatura , Animais , Metabolismo Basal/genética , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Calorimetria/instrumentação , Metabolismo Energético/genética , Humanos , Larva/citologia , Larva/genética , Larva/metabolismo , Longevidade/genética , Modelos Animais , Mutação , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Reprodutibilidade dos Testes , Análise de Célula Única/instrumentação , Condutividade Térmica
7.
Nat Commun ; 11(1): 2476, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424161

RESUMO

Birds (Aves) display high metabolic rates and oxygen consumption relative to mammals, increasing reactive oxygen species (ROS) formation. Although excess ROS reduces lifespan by causing extensive cellular dysfunction and damage, birds are remarkably long-lived. We address this paradox by identifying the constitutive activation of the NRF2 master antioxidant response in Neoaves (~95% of bird species), providing an adaptive mechanism capable of counterbalancing high ROS levels. We demonstrate that a KEAP1 mutation in the Neoavian ancestor disrupted the repression of NRF2 by KEAP1, leading to constitutive NRF2 activity and decreased oxidative stress in wild Neoaves tissues and cells. Our evidence suggests this ancient mutation induced a compensatory program in NRF2-target genes with functions beyond redox regulation-including feather development-while enabling significant metabolic rate increases that avoid trade-offs with lifespan. The strategy of NRF2 activation sought by intense clinical investigation therefore appears to have also unlocked a massively successful evolutionary trajectory.


Assuntos
Adaptação Fisiológica , Antioxidantes/metabolismo , Aves/fisiologia , Plumas/crescimento & desenvolvimento , Longevidade/fisiologia , Animais , Metabolismo Basal , Evolução Biológica , Aves/genética , Núcleo Celular/metabolismo , Fibroblastos/metabolismo , Genômica , Glutationa Transferase/metabolismo , Células HEK293 , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Filogenia , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Transporte Proteico , Ubiquitinação , Regulação para Cima/genética
8.
J Sports Sci ; 38(14): 1635-1649, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32397898

RESUMO

The systematic review and meta-analysis evaluated the effect of aerobic, resistance and combined exercise on RMR (kCal·day-1) and performed a methodological assessment of indirect calorimetry protocols within the included studies. Subgroup analyses included energy/diet restriction and body composition changes. Randomized control trials (RCTs), quasi - RCTs and cohort trials featuring a physical activity intervention of any form and duration excluding single exercise bouts were included. Participant exclusions included medical conditions impacting upon RMR, the elderly (≥65 years of age) or pregnant, lactating or post-menopausal women. The review was registered in the International Prospective Register of Systematic Reviews (CRD 42,017,058,503). 1669 articles were identified; 22 were included in the qualitative analysis and 18 were meta-analysed. Exercise interventions (aerobic and resistance exercise combined) did not increase resting metabolic rate (mean difference (MD): 74.6 kCal·day-1[95% CI: -13.01, 161.33], P = 0.10). While there was no effect of aerobic exercise on RMR (MD: 81.65 kCal·day-1[95% CI: -57.81, 221.10], P = 0.25), resistance exercise increased RMR compared to controls (MD: 96.17 kCal·day-1[95% CI: 45.17, 147.16], P = 0.0002). This systematic review effectively synthesises the effect of exercise interventions on RMR in comparison to controls; despite heterogenous methodologies and high risk of bias within included studies.


Assuntos
Metabolismo Basal/fisiologia , Exercício Físico/fisiologia , Calorimetria Indireta , Humanos , Treinamento de Resistência
10.
Obesity (Silver Spring) ; 28(5): 902-906, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32320142

RESUMO

OBJECTIVE: The aim of this study was to investigate whether baseline (pre-weight loss) metabolic variables can predict weight regain. METHODS: About 117 women with overweight completed a weight loss program to achieve BMI < 25 kg/m2 and were followed for 2 years. Resting metabolic rate, respiratory quotient, insulin sensitivity, and serum leptin concentration were measured pre-weight loss, while on energy balance, and as predictors of weight regain at 1 and 2 years. Rate and amount of weight loss also were examined as predictors, as these outcomes may reflect metabolic phenotype. RESULTS: Average weight loss was 12 (SD 2.5) kg, and regain was 48% (SD 35%) and 80% (SD 52%) at 1 and 2 years, respectively. In regression modeling, metabolic variables (both pre-weight loss and changes with weight loss) did not predict weight regain. However, initial weight loss and time to achieve BMI < 25 were significant predictors of weight regain at 1 and 2 years, even after adjusting for confounders. CONCLUSIONS: Baseline (pre-weight loss) resting metabolic rate, respiratory quotient, insulin sensitivity, and leptin did not predict weight regain. However, a larger and faster weight loss was associated with a lower weight regain. Understanding the mechanisms behind interindividual variation in magnitude and rate of weight loss is needed to ensure better weight loss maintenance.


Assuntos
Metabolismo Basal/fisiologia , Obesidade/metabolismo , Ganho de Peso/fisiologia , Adulto , Feminino , Humanos , Masculino , Pré-Menopausa , Adulto Jovem
11.
Eur J Clin Microbiol Infect Dis ; 39(7): 1209-1220, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32328850

RESUMO

To analyze the susceptibility of SARS-CoV-2 in pregnancy and the drugs that can be used to treat pregnancy with COVID-19, so as to provide evidence for drug selection in clinic. By reviewing the existing literature, this paper analyzes the susceptibility of pregnant women to virus, especially to SARS-CoV-2, from the aspects of anatomical, reproductive endocrine and immune changes during pregnancy and screens effective and fetal-safe treatments from the existing drugs. The anatomical structure of the respiratory system is changed during pregnancy, and the virus transmitted by droplets and aerosols is more easily inhaled by pregnant women and is difficult to remove. Furthermore, the prognosis is worse after infection when compared with non-pregnancy women. And changes in reproductive hormones and immune systems during pregnancy collectively make them more susceptible to certain infections. More importantly, angiotensin-converting enzyme (ACE)-2, the SARS-CoV-2 receptor, has been proven highly increased during pregnancy, which may contribute to the susceptibility to SARS-CoV-2. When it comes to treatment, specific drugs for COVID-19 have not been found at present, and taking old drugs for new use in treating COVID-19 has become an emergency method for the pandemic. Particularly, drugs that show superior maternal and fetal safety are worthy of consideration for pregnant women with COVID-19, such as chloroquine, metformin, statins, lobinavir/ritonavir, glycyrrhizic acid, and nanoparticle-mediated drug delivery (NMDD), etc. Pregnant women are susceptible to COVID-19, and special attention should be paid to the selection of drugs that are both effective for maternal diseases and friendly to the fetus. However, there are still many deficiencies in the study of drug safety during pregnancy, and broad-spectrum, effective and fetal-safe drugs for pregnant women need to be developed so as to cope with more infectious diseases in the future.


Assuntos
Fenômenos Fisiológicos Cardiovasculares , Infecções por Coronavirus/metabolismo , Pneumonia Viral/metabolismo , Complicações Infecciosas na Gravidez/metabolismo , Gravidez/fisiologia , Fenômenos Fisiológicos Respiratórios , Anti-Inflamatórios/uso terapêutico , Antimaláricos/uso terapêutico , Antivirais/uso terapêutico , Metabolismo Basal , Betacoronavirus/metabolismo , Cloroquina/uso terapêutico , Anormalidades Congênitas/epidemiologia , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Suscetibilidade a Doenças/imunologia , Suscetibilidade a Doenças/metabolismo , Combinação de Medicamentos , Sistemas de Liberação de Medicamentos , Feminino , Capacidade Residual Funcional , Ácido Glicirrízico/uso terapêutico , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipoglicemiantes/uso terapêutico , Interferon Tipo I/uso terapêutico , Lopinavir/uso terapêutico , Metformina/uso terapêutico , Nanopartículas , Consumo de Oxigênio , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Gravidez/imunologia , Gravidez/metabolismo , Complicações Infecciosas na Gravidez/tratamento farmacológico , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/imunologia , Progesterona/metabolismo , Prognóstico , Ritonavir/uso terapêutico , Glicoproteína da Espícula de Coronavírus/metabolismo , Natimorto/epidemiologia , Relação Ventilação-Perfusão
12.
PLoS One ; 15(4): e0228527, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32275675

RESUMO

Securing economically and ecologically significant molluscs, as our oceans warm due to climate change, is a global priority. South eastern Australia receives warm water in a strengthening East Australia Current and so resident species are vulnerable to elevated temperature and marine heat waves. This study tested whether prior exposure to elevated temperature can enhance resilience of oysters to ocean warming. Two Australian species, the flat oyster, Ostrea angasi, and the Sydney rock oyster, Saccostrea glomerata, were obtained as adults and "heat shocked" by exposure to a dose of warm water in the laboratory. Oysters were then transferred to elevated seawater temperature conditions where the thermal outfall from power generation was used as a proxy to investigate the impacts of ocean warming. Shell growth, condition index, lipid content and survival of flat oysters and condition of Sydney rock oysters were all significantly reduced by elevated seawater temperature in the field. Flat oysters grew faster than Sydney rock oysters at ambient temperature, but their growth and survival was more sensitive to elevated temperature. "Stress inoculation" by heat shock did little to ameliorate the negative effects of increased temperature, although the survival of heat-shocked flat oysters was greater than non-heat shocked oysters. Further investigations are required to determine if early exposure to heat stress can enhance resilience of oysters to ocean warming.


Assuntos
Adaptação Fisiológica , Mudança Climática , Oceanos e Mares , Ostreidae/fisiologia , Estresse Fisiológico , Exoesqueleto/crescimento & desenvolvimento , Animais , Austrália , Metabolismo Basal , Lipídeos/análise , Análise de Sobrevida , Temperatura
13.
PLoS One ; 15(4): e0231091, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32240240

RESUMO

Acute heat shock has previously been shown to improve subsequent low O2 (hypoxia) tolerance in an intertidal fish species, a process known as cross-tolerance, but it is not known whether this is a widespread phenomenon. This study examined whether a rock pool specialist, the triplefin fish Bellapiscis medius, exhibits heat shock induced cross-tolerance to hypoxia, i.e., longer time to loss of equilibrium (LOE) and lower critical O2 saturation (Scrit) after recovering from an acute heat challenge. Non-heat shock controls had a median time to loss of equilibrium (LOE50) of 54.4 min under severe hypoxia (7% of air saturation) and a Scrit of 15.8% air saturation. Contrary to expectations, however, treatments that received an 8 or 10°C heat shock showed a significantly shorter LOE50 in hypoxia (+8°C = 41.5 min; +10°C = 28.7 min) and no significant change in Scrit (+8°C = 17.0% air saturation; +10°C = 18.3% of air saturation). Thus, there was no evidence of heat shock induced cross-tolerance to hypoxia in B. medius because exposure to acute heat shock impaired hypoxia tolerance.


Assuntos
Adaptação Fisiológica , Peixes/fisiologia , Temperatura Alta , Hipóxia/fisiopatologia , Movimentos da Água , Animais , Metabolismo Basal , Resposta ao Choque Térmico/fisiologia , Oxigênio/metabolismo , Análise de Sobrevida
14.
PLoS One ; 15(4): e0223548, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32255792

RESUMO

This investigation examined anthropometric, hormonal, and physiological differences between advanced (ADV; n = 8, 27.8 ± 4.2 years, 170 ± 11 cm, 79.8 ± 13.3 kg) and recreational (REC; n = 8, 33.5 ± 8.1 years, 172 ± 14 cm, 76.3 ± 19.5 kg) CrossFit (CF) trained participants in comparison to physically-active controls (CON; n = 7, 27.5 ± 6.7 years, 171 ± 14 cm, 74.5 ± 14.3 kg). ADV and REC were distinguished by their past competitive success. REC and CON were resistance-trained (>2 years) and exercised on 3-5 days·wk-1 for the past year, but CON utilized traditional resistance and cardiovascular exercise. All participants provided a fasted, resting blood sample and completed assessments of resting metabolic rate, body composition, muscle morphology, isometric mid-thigh pull strength, peak aerobic capacity, and a 3-minute maximal cycle ergometer sprint across two separate occasions (separated by 3-7 days). Blood samples were analyzed for testosterone, cortisol, and insulin-like growth factor-1. Compared to both REC and CON, one-way analysis of variance revealed ADV to possess lower body fat percentage (6.7-8.3%, p = 0.007), greater bone and non-bone lean mass (12.5-26.8%, p ≤ 0.028), muscle morphology characteristics (14.2-59.9%, p < 0.05), isometric strength characteristics (15.4-41.8%, p < 0.05), peak aerobic capacity (18.8-19.1%, p = 0.002), and 3-minute cycling performance (15.4-51.1%, p ≤ 0.023). No differences were seen between REC and CON, or between all groups for resting metabolic rate or hormone concentrations. These data suggest ADV possess several physiological advantages over REC and CON, whereas similar physiological characteristics were present in individuals who have been regularly participating in either CF or resistance and cardiovascular training for the past year.


Assuntos
Atletas , Metabolismo Basal , Composição Corporal , Aptidão Cardiorrespiratória , Treinamento de Resistência/métodos , Adulto , Feminino , Estilo de Vida Saudável/fisiologia , Hormônios/sangue , Humanos , Contração Isométrica , Masculino , Treinamento de Resistência/efeitos adversos
15.
Am J Clin Nutr ; 111(5): 983-996, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32145012

RESUMO

BACKGROUND: Knowledge on resting energy expenditure (REE) in spinal muscular atrophy type I (SMAI) is still limited. The lack of a population-specific REE equation has led to poor nutritional support and impairment of nutritional status. OBJECTIVE: To identify the best predictors of measured REE (mREE) among simple bedside parameters, to include these predictors in population-specific equations, and to compare such models with the common predictive equations. METHODS: Demographic, clinical, anthropometric, and treatment variables were examined as potential predictors of mREE by indirect calorimetry (IC) in 122 SMAI children consecutively enrolled in an ongoing longitudinal observational study. Parameters predicting REE were identified, and prespecified linear regression models adjusted for nusinersen treatment (discrete: 0 = no; 1 = yes) were used to develop predictive equations, separately in spontaneously breathing and mechanically ventilated patients. RESULTS: In naïve patients, the median (25th, 75th percentile) mREE was 480 (412, 575) compared with 394 (281, 554) kcal/d in spontaneously breathing and mechanically ventilated patients, respectively (P = 0.009).In nusinersen-treated patients, the median (25th, 75th percentile) mREE was 609 (592, 702) compared with 639 (479, 723) kcal/d in spontaneously breathing and mechanically ventilated patients, respectively (P = 0.949).Both in spontaneously breathing and mechanically ventilated patients, the best prediction of REE was obtained from 3 models, all using as predictors: 1 body size related measurement and nusinersen treatment status. Nusinersen treatment was correlated with higher REE both in spontaneously breathing and mechanically ventilated patients. The population-specific equations showed a lower interindividual variability of the bias than the other equation tested, however, they showed a high root mean squared error. CONCLUSIONS: We demonstrated that ventilatory status, nusinersen treatment, demographic, and anthropometric characteristics determine energy requirements in SMAI. Our SMAI-specific equations include variables available in clinical practice and were generally more accurate than previously published equations. At the individual level, however, IC is strongly recommended for assessing energy requirements. Further research is needed to externally validate these predictive equations.


Assuntos
Atrofias Musculares Espinais da Infância/metabolismo , Metabolismo Basal , Calorimetria Indireta , Criança , Pré-Escolar , Metabolismo Energético , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Necessidades Nutricionais , Estado Nutricional , Oligonucleotídeos/administração & dosagem , Atrofias Musculares Espinais da Infância/genética , Atrofias Musculares Espinais da Infância/terapia , Ventiladores Mecânicos
16.
J Endocrinol ; 244(2): R17-R32, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31972543

RESUMO

Torpid states are used by many endotherms to save energy during winter. During torpor, metabolic rate is downregulated to fractions of resting metabolic rate and often associated with a severe drop in body temperature that challenges mammalian physiology. Understanding the mechanisms regulating this extreme depression of metabolism bears enormous potential for biomedical research. Torpor behavior has been extensively studied in the Djungarian hamster, also known as Siberian hamster. It is dependent on many preparatory adaptations of physiological and endocrine systems that are likely to be integrated by the hypothalamus eventually controlling metabolism. Although substantial knowledge exists about prerequisites and characteristics of torpor in this species, the cascade of events and their mechanisms of action are not well understood. This review summarizes the current state of knowledge about mechanisms of metabolic regulation in the Djungarian hamster focusing on the potential roles of thyroid hormone and glucose metabolism.


Assuntos
Metabolismo Energético , Phodopus/fisiologia , Adaptação Fisiológica , Animais , Metabolismo Basal , Cricetinae , Glucose/metabolismo , Estações do Ano , Hormônios Tireóideos/metabolismo
17.
Ecol Lett ; 23(4): 642-652, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31990148

RESUMO

Survival rates vary dramatically among species and predictably across latitudes, but causes of this variation are unclear. The rate-of-living hypothesis posits that physiological damage from metabolism causes species with faster metabolic rates to exhibit lower survival rates. However, whether increased survival commonly observed in tropical and south temperate latitudes is associated with slower metabolic rate remains unclear. We compared metabolic rates and annual survival rates that we measured across 46 species, and from literature data across 147 species of birds in northern, southern and tropical latitudes. High metabolic rates were associated with lower survival but survival varied substantially among latitudinal regions independent of metabolism. The inability of metabolic rate to explain latitudinal variation in survival suggests (1) species may evolve physiological mechanisms that mitigate physiological damage from cellular metabolism and (2) extrinsic rather than intrinsic sources of mortality are the primary causes of latitudinal differences in survival.


Assuntos
Aves Canoras , Animais , Metabolismo Basal
18.
Scand J Med Sci Sports ; 30(3): 408-420, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31674694

RESUMO

Sarcolipin (SLN) is a SERCA uncoupling protein associated with exercise performance and lower adiposity in mice. To determine SLN protein expression in human skeletal muscle and its relationship with adiposity, resting energy expenditure (REE), and performance, SLN was assessed by Western blot in 199 biopsies from two previous studies. In one study, 15 overweight volunteers underwent a pretest followed by 4 days of caloric restriction and exercise (45-minute one-arm cranking + 8-hour walking), and 3 days on a control diet. Muscle biopsies were obtained from the trained and non-exercised deltoid, and vastus lateralis (VL). In another study, 16 men performed seven sessions of 4-6 × 30-sec all-out sprints on the cycle ergometer with both limbs, and their VL and triceps brachii biopsied pre- and post-training. SLN expression was twofold and 44% higher in the VL than in the deltoids and triceps brachii, respectively. SLN was associated with neither adiposity nor REE, and was not altered by a severe energy deficit (5500 kcal/day). SLN and cortisol changes after the energy deficit were correlated (r = .38, P = .039). SLN was not altered by low-intensity exercise in the overweight subjects, whereas it was reduced after sprint training in the other group. The changes in SLN with sprint training were inversely associated with the changes in gross efficiency (r = -.59, P = .016). No association was observed between aerobic or anaerobic performance and SLN expression. In conclusion, sarcolipin appears to play no role in regulating the fat mass of men. Sprint training reduces sarcolipin expression, which may improve muscle efficiency.


Assuntos
Metabolismo Basal , Metabolismo Energético , Exercício Físico , Proteínas Musculares/fisiologia , Músculo Esquelético/fisiologia , Proteolipídeos/fisiologia , Adulto , Composição Corporal , Restrição Calórica , Humanos , Masculino , Pessoa de Meia-Idade , Sobrepeso , Adulto Jovem
19.
Scand J Med Sci Sports ; 30(1): 135-147, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31593622

RESUMO

INTRODUCTION: Competing in aesthetic sports increases the risk of low energy availability and associated health impairments. Fitness physique sport is a popular, but understudied aesthetic sport. We evaluated health and symptoms of relative energy deficiency in sport (RED-s) in female fitness athletes (FA) and female references (FR) during a competitive season. METHODS: Totally, 25 FA and 26 FR, mean (SD) age of 28.9 (5.7), were included. Assessments were at baseline (T1), 2-weeks pre-competition (T2), and 1-month post-competition (T3), by dual-energy x-ray absorptiometry scan, indirect calorimetry, diet registration, The Low Energy Availability in Females Questionnaire, The Beck Depression Inventory, and Eating Disorder Examination Questionnaire (EDE-Q). RESULTS: A history of eating disorders was reported by 35% FA and 12% FR. There were no between-group differences at T1, besides less mean (99% CI) fat mass (FM) of 3.1 kg (-0.4, 6.5) in FA (P = .02). At T2, FA had lower BW of 6.7 kg (-12.0, -1.3), fat mass of -9.0 kg (-12.5, -5.5), and resting heart rate of -8.0 beats per minute (-14.5, -1.5) compared to FR (P ≤ .006). FA reduced resting metabolic rate by -191 kcal (-11, -371) and increased symptoms of gastrointestinal dysfunction (GD) by 1.4 points (0.3, 2.5) and prevalence of amenorrhea from 8% to 24%, (P < .003). At T3, there was a between-group difference in fat mass, and a high number of FA with amenorrhea and GD. CONCLUSION: Manifestation of symptoms of RED-s, some with persistence one-month post-competition, raises concern for the health of FA and those complying with the fit body ideal.


Assuntos
Deficiência Energética Relativa no Esporte/diagnóstico , Absorciometria de Fóton , Adulto , Amenorreia , Atletas , Metabolismo Basal , Composição Corporal , Peso Corporal , Calorimetria Indireta , Comportamento Competitivo , Dieta , Transtornos da Alimentação e da Ingestão de Alimentos , Feminino , Frequência Cardíaca , Humanos , Noruega , Inquéritos e Questionários , Adulto Jovem
20.
Chemosphere ; 238: 124584, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31470313

RESUMO

Exposure to endocrine disrupting chemicals has been suggested to contribute to the ongoing globally increasing obesity trend. The complex chemical mixtures that humans and wildlife are exposed to include a number of compounds that may have obesogenic properties. In this study we examined a mixture consisting of phthalate-monoesters, triclosan, and perfluorinated compounds. The mixture was designed within the EDC-MixRisk project based on serum levels of the compounds in pregnant women of a Swedish mother-child cohort. The compounds were negatively associated with birth weight of the children. We assessed whether developmental exposure to this mixture in combination with a calorie-rich diet affected metabolic rate, blood lipids, adipogenesis and lipid storage, and the whole-body level of neutral lipids in zebrafish (Danio rerio). Wildtype zebrafish were exposed to the mixture from 3 h post fertilization to 5, 14 or 17 days post fertilization (dpf) at water concentrations corresponding to 1, 10, 20, or 100 times the geometrical mean of the serum concentration (hsc) in the women. Exposure to the mixture at 20 times hsc lowered metabolic rate at 2-5 dpf, and increased the number of adipocytes and the amount of visceral adipose tissue at 14 and 17 dpf respectively. Also, mRNA expression of fatty acid binding protein 11a was increased at 17 dpf by 10 and 20 times hsc of the mixture. This study shows that a human-relevant mixture of environmental pollutants affects metabolic rate, adipogenesis and lipid storage in young zebrafish fed a calorie-rich diet, thus demonstrating its potential to disrupt metabolism.


Assuntos
Adipogenia/efeitos dos fármacos , Metabolismo Basal/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Peso ao Nascer/efeitos dos fármacos , Proteínas de Ligação a Ácido Graxo/biossíntese , Proteínas de Ligação a Ácido Graxo/genética , Feminino , Humanos , Hidrocarbonetos Fluorados/toxicidade , Ácidos Ftálicos/toxicidade , Gravidez , Triclosan/toxicidade , Proteínas de Peixe-Zebra/biossíntese , Proteínas de Peixe-Zebra/genética
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