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1.
PLoS One ; 15(8): e0237769, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817718

RESUMO

Concerns exist that the positive association of physical activity with better lung function, which has been suggested in previous longitudinal studies in smokers, is due to reverse causation. To investigate this, we applied structural equation modeling (SEM), an exploratory approach, and marginal structural modeling (MSM), an approach from the causal inference framework that corrects for reverse causation and time-dependent confounding and estimates causal effects, on data from participants in the European Community Respiratory Health Survey (ECRHS, a multicentre European cohort study initiated in 1991-1993 with ECRHS I, and with two follow-ups: ECRHS II in 1999-2003, and ECRHS III in 2010-2014). 753 subjects who reported current smoking at ECRHS II, with repeated data on lung function at ECRHS I, II and III, physical activity at ECRHS II and III, and potential confounders at ECRHS I and II, were included in the analyses. SEM showed positive associations between physical activity and lung function in both directions. MSM suggested a protective causal effect of physical activity on lung function (overall difference in mean ß (95% CI), comparing active versus non-active individuals: 58 mL (21-95) for forced expiratory volume in one second and 83 mL (36-130) for forced vital capacity). Our results suggest bi-directional causation and support a true protective effect of physical activity on lung function in smokers, after accounting for reverse causation and time-dependent confounding.


Assuntos
Asma/terapia , Exercício Físico , Pulmão/fisiologia , Infecções Respiratórias/terapia , Adolescente , Adulto , Asma/etiologia , Asma/fisiopatologia , Peso Corporal/fisiologia , Dieta , Feminino , Volume Expiratório Forçado/fisiologia , Inquéritos Epidemiológicos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Testes de Função Respiratória , Fumantes , Fumar/efeitos adversos , Capacidade Vital/fisiologia , Adulto Jovem
2.
PLoS One ; 15(7): e0233877, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645021

RESUMO

BACKGROUND: The impact of nutritional supplements on weight gain in HIV-infected children on antiretroviral treatment (ART) remains uncertain. Starting supplements depends upon current weight-for-age or other acute malnutrition indicators, producing time-dependent confounding. However, weight-for-age at ART initiation may affect subsequent weight gain, independent of supplement use. Implications for marginal structural models (MSMs) with inverse probability of treatment weights (IPTW) are unclear. METHODS: In the ARROW trial, non-randomised supplement use and weight-for-age were recorded monthly from ART initiation. The effect of supplements on weight-for-age over the first year was estimated using generalised estimating equation MSMs with IPTW, both with and without interaction terms between baseline weight-for-age and time. Separately, data were simulated assuming no supplement effect, with use depending on current weight-for-age, and weight-for-age trajectory depending on baseline weight-for-age to investigate potential bias associated with different MSM specifications. RESULTS: In simulations, despite correctly specifying IPTW, omitting an interaction in the MSM between baseline weight-for-age and time produced increasingly biased estimates as associations between baseline weight-for-age and subsequent weight trajectory increased. Estimates were unbiased when the interaction between baseline weight-for-age and time was included, even if the data were simulated with no such interaction. In ARROW, without an interaction the estimated effect was +0.09 (95%CI +0.02,+0.16) greater weight-for-age gain per month's supplement use; this reduced to +0.03 (-0.04,+0.10) including the interaction. DISCUSSION: This study highlights a specific situation in which MSM model misspecification can occur and impact the resulting estimate. Since an interaction in the MSM (outcome) model does not bias the estimate of effect if the interaction does not exist, it may be advisable to include such a term when fitting MSMs for repeated measures.


Assuntos
Infecções por HIV/dietoterapia , Apoio Nutricional/métodos , Ganho de Peso/efeitos dos fármacos , Antirretrovirais/uso terapêutico , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Pré-Escolar , Suplementos Nutricionais/análise , Feminino , HIV/patogenicidade , Infecções por HIV/metabolismo , Humanos , Lactente , Masculino , Modelos Estatísticos , Modelagem Computacional Específica para o Paciente , Projetos de Pesquisa
3.
BMJ ; 370: m2322, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669369

RESUMO

OBJECTIVE: To analyse the health and environmental implications of adopting national food based dietary guidelines (FBDGs) at a national level and compared with global health and environmental targets. DESIGN: Modelling study. SETTING: 85 countries. PARTICIPANTS: Population of 85 countries. MAIN OUTCOME MEASURES: A graded coding method was developed and used to extract quantitative recommendations from 85 FBDGs. The health and environmental impacts of these guidelines were assessed by using a comparative risk assessment of deaths from chronic diseases and a set of country specific environmental footprints for greenhouse gas emissions, freshwater use, cropland use, and fertiliser application. For comparison, the impacts of adopting the global dietary recommendations of the World Health Organization and the EAT-Lancet Commission on Healthy Diets from Sustainable Food Systems were also analysed. Each guideline's health and sustainability implications were assessed by modelling its adoption at both the national level and globally, and comparing the impacts to global health and environmental targets, including the Action Agenda on Non-Communicable Diseases, the Paris Climate Agreement, the Aichi biodiversity targets related to land use, and the sustainable development goals and planetary boundaries related to freshwater use and fertiliser application. RESULTS: Adoption of national FBDGs was associated with reductions in premature mortality of 15% on average (95% uncertainty interval 13% to 16%) and mixed changes in environmental resource demand, including a reduction in greenhouse gas emissions of 13% on average (regional range -34% to 35%). When universally adopted globally, most of the national guidelines (83, 98%) were not compatible with at least one of the global health and environmental targets. About a third of the FBDGs (29, 34%) were incompatible with the agenda on non-communicable diseases, and most (57 to 74, 67% to 87%) were incompatible with the Paris Climate Agreement and other environmental targets. In comparison, adoption of the WHO recommendations was associated with similar health and environmental changes, whereas adoption of the EAT-Lancet recommendations was associated with 34% greater reductions in premature mortality, more than three times greater reductions in greenhouse gas emissions, and general attainment of the global health and environmental targets. As an example, the FBDGs of the UK, US, and China were incompatible with the climate change, land use, freshwater, and nitrogen targets, and adopting guidelines in line with the EAT-Lancet recommendation could increase the number of avoided deaths from 78 000 (74 000 to 81 000) to 104 000 (96 000 to 112 000) in the UK, from 480 000 (445 000 to 516 000) to 585 000 (523 000 to 646 000) in the USA, and from 1 149 000 (1 095 000 to 1 204 000) to 1 802 000 (1 664 000 to 1 941 000) in China. CONCLUSIONS: This analysis suggests that national guidelines could be both healthier and more sustainable. Providing clearer advice on limiting in most contexts the consumption of animal source foods, in particular beef and dairy, was found to have the greatest potential for increasing the environmental sustainability of dietary guidelines, whereas increasing the intake of whole grains, fruits and vegetables, nuts and seeds, and legumes, reducing the intake of red and processed meat, and highlighting the importance of attaining balanced energy intake and weight levels were associated with most of the additional health benefits. The health results were based on observational data and assuming a causal relation between dietary risk factors and health outcomes. The certainty of evidence for these relations is mostly graded as moderate in existing meta-analyses.


Assuntos
Dieta/normas , Política Nutricional/legislação & jurisprudência , Desenvolvimento Sustentável/legislação & jurisprudência , Peso Corporal/fisiologia , Doença Crônica/mortalidade , Dieta/tendências , Dieta Saudável/normas , Ingestão de Alimentos/fisiologia , Ingestão de Energia/fisiologia , Saúde Ambiental/estatística & dados numéricos , Estudos de Avaliação como Assunto , Saúde Global/estatística & dados numéricos , Gases de Efeito Estufa/efeitos adversos , Nível de Saúde , Humanos , Modelos Teóricos , Doenças não Transmissíveis/epidemiologia , Doenças não Transmissíveis/prevenção & controle , Política Nutricional/tendências , Medição de Risco , Desenvolvimento Sustentável/tendências , Organização Mundial da Saúde/organização & administração
4.
Am J Physiol Regul Integr Comp Physiol ; 319(2): R203-R210, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32609535

RESUMO

Canids are a morphological and physiological diverse group of animals, with the most diversity found within one species, the domestic dog. Underlying observed morphological differences, there must also be differences at other levels of organization that could lead to elucidating aging rates and life span disparities between wild and domestic canids. Furthermore, small-breed dogs live significantly longer lives than large-breed dogs, while having higher mass-specific metabolic rates and faster growth rates. At the cellular level, a clear mechanism underlying whole animal traits has not been fully elucidated, although oxidative stress has been implicated as a potential culprit of the disparate life spans of domestic dogs. We used plasma and red blood cells from known aged domestic dogs and wild canids, and measured several oxidative stress variables: total antioxidant capacity (TAC), lipid damage, and enzymatic activities of catalase, superoxide dismutase, and glutathione peroxidase (GPx). We used phylogenetically informed general linear mixed models and nonphylogenetically corrected linear regression analysis. We found that lipid damage increases with age in domestic dogs, whereas TAC increases with age and TAC and GPx activity increases as a function of age/maximum life span in wild canids, which may partly explain longer potential life spans in wolves. As body mass increases, TAC and GPx activity increase in wild canids, but not domestic dogs, highlighting that artificial selection may have decreased antioxidant capacity in domestic dogs. We found that small-breed dogs have significantly higher circulating lipid damage compared with large-breed dogs, concomitant to their high mass-specific metabolism and higher growth rates, but in opposition to their long life spans.


Assuntos
Peso Corporal/fisiologia , Longevidade/fisiologia , Estresse Oxidativo/fisiologia , Animais , Canidae , Catalase/sangue , Cães , Feminino , Glutationa Peroxidase/sangue , Masculino , Oxirredução , Filogenia , Superóxido Dismutase/sangue
5.
PLoS Med ; 17(7): e1003168, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32673309

RESUMO

BACKGROUND: Several studies have suggested that reduced sleep duration and quality are associated with an increased risk of obesity and related metabolic disorders, but the role of sleep in long-term weight loss maintenance (WLM) has not been thoroughly explored using prospective data. METHODS AND FINDINGS: The present study is an ancillary study based on data collected on participants from the Navigating to a Healthy Weight (NoHoW) trial, for which the aim was to test the efficacy of an evidence-based digital toolkit, targeting self-regulation, motivation, and emotion regulation, on WLM among 1,627 British, Danish, and Portuguese adults. Before enrolment, participants had achieved a weight loss of ≥5% and had a BMI of ≥25 kg/m2 prior to losing weight. Participants were enrolled between March 2017 and March 2018 and followed during the subsequent 12-month period for change in weight (primary trial outcome), body composition, metabolic markers, diet, physical activity, sleep, and psychological mediators/moderators of WLM (secondary trial outcomes). For the present study, a total of 967 NoHoW participants were included, of which 69.6% were women, the mean age was 45.8 years (SD 11.5), the mean baseline BMI was 29.5 kg/m2 (SD 5.1), and the mean weight loss prior to baseline assessments was 11.4 kg (SD 6.4). Objectively measured sleep was collected using the Fitbit Charge 2 (FC2), from which sleep duration, sleep duration variability, sleep onset, and sleep onset variability were assessed across 14 days close to baseline examinations. The primary outcomes were 12-month changes in body weight (BW) and body fat percentage (BF%). The secondary outcomes were 12-month changes in obesity-related metabolic markers (blood pressure, low- and high-density lipoproteins [LDL and HDL], triglycerides [TGs], and glycated haemoglobin [HbA1c]). Analysis of covariance and multivariate linear regressions were conducted with sleep-related variables as explanatory and subsequent changes in BW, BF%, and metabolic markers as response variables. We found no evidence that sleep duration, sleep duration variability, or sleep onset were associated with 12-month weight regain or change in BF%. A higher between-day variability in sleep onset, assessed using the standard deviation across all nights recorded, was associated with weight regain (0.55 kg per hour [95% CI 0.10 to 0.99]; P = 0.016) and an increase in BF% (0.41% per hour [95% CI 0.04 to 0.78]; P = 0.031). Analyses of the secondary outcomes showed that a higher between-day variability in sleep duration was associated with an increase in HbA1c (0.02% per hour [95% CI 0.00 to 0.05]; P = 0.045). Participants with a sleep onset between 19:00 and 22:00 had the greatest reduction in diastolic blood pressure (DBP) (P = 0.02) but also the most pronounced increase in TGs (P = 0.03). The main limitation of this study is the observational design. Hence, the observed associations do not necessarily reflect causal effects. CONCLUSION: Our results suggest that maintaining a consistent sleep onset is associated with improved WLM and body composition. Sleep onset and variability in sleep duration may be associated with subsequent change in different obesity-related metabolic markers, but due to multiple-testing, the secondary exploratory outcomes should be interpreted cautiously. TRIAL REGISTRATION: The trial was registered with the ISRCTN registry (ISRCTN88405328).


Assuntos
Peso Corporal/fisiologia , Sono/fisiologia , Adulto , Composição Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Perda de Peso
6.
Nutr. hosp ; 37(3): 584-588, mayo-jun. 2020. tab, graf
Artigo em Inglês | IBECS | ID: ibc-193867

RESUMO

INTRODUCTION: to avoid rapid body mass fluctuations and the associated effects on health and performance, some combat sports federations have made changes to regulations. OBJECTIVE: the objective of this study was to analyze the impact of the Rapid Weight Gain on sporting success in elite Olympic wrestling athletes under the new weigh-in procedure. METHODS: the body mass of 75 athletes was recorded during the Pan-American Olympic wrestling Championship (Lima, 2018), corresponding to 29 % of the total universe of competitors (n = 255). Of these, 29 were Greco-Roman style, eight freestyle, and 38 women's wrestling. The official weigh-in was carried out between 8:00 and 8:30 hours. As for the second weigh-in, this was done with the same official weigh-in scale, immediately before the first match (between 10:00 and 11:00 hours). Rapid Weight Gain after weigh-in was compared between medalist and non-medalist athletes. RESULTS: when analyzing the difference between medalists and non-medalists, no significant differences were found in Greco-Roman athletes (t = 0.114; p = 0.910; r = 0.022), in freestyle (Mann-Whitney U = 5,500; p = 0.486; r = 0.000), in women's wrestling (Mann-Whitney U = 163.0; p = 0.774; r = 0.124), and in all competitors (Mann-Whitney U = 641.5; p = 0.855; r = 0.037). CONCLUSIONS: no significant differences were found between medalist and non-medalist athletes in any of the Olympic wrestling styles


INTRODUCCIÓN: para evitar fluctuaciones rápidas del peso corporal y los efectos asociados sobre la salud y rendimiento, algunas federaciones de deportes de combate han realizado cambios de reglamento. OBJETIVO: el objetivo de este estudio fue analizar el impacto de la ganancia rápida de peso en el éxito deportivo en atletas de élite de la lucha olímpica bajo la nueva modalidad de pesaje. MÉTODOS: se registró el peso corporal de 75 atletas durante el Campeonato Panamericano de Lucha Olímpica (Lima, 2018), correspondiente al 29 % del universo total de competidores (n = 255). De estos, 29 fueron de estilo grecorromano; 8, de estilo libre y 38, de lucha libre femenina. El pesaje oficial se realizó entre las 8:00 y las 8:30 horas. En cuanto al segundo pesaje, se hizo con la misma balanza oficial inmediatamente antes de la primera lucha (entre las 10:00 y las 11:00 horas). La ganancia de peso rápida después del pesaje se comparó entre atletas medallistas y no medallistas. RESULTADOS: al analizar la diferencia entre medallistas y no medallistas, no se encontraron diferencias significativas en los atletas de grecorromana (t = 0,114; p = 0,910; r = 0,022), en los de estilo libre (Mann-Whitney U = 5,500; p = 0,486; r = 0,000), en los de lucha libre femenina (Mann-Whitney U = 163,0; p = 0,774; r = 0,124) ni en todos los competidores (Mann -Whitney U = 641,5; p = 0,855; r = 0,037). CONCLUSIONES: no se encontraron diferencias significativas entre atletas medallistas y no medallistas en ninguno de los estilos de lucha olímpica


Assuntos
Humanos , Ganho de Peso/fisiologia , Atletas , Luta Romana/fisiologia , Peso Corporal/fisiologia , Peru , Perda de Peso/fisiologia , Análise de Variância , Índice de Massa Corporal
7.
PLoS One ; 15(6): e0233910, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32502215

RESUMO

Farmers face difficulties in redeeming their investment in larger litter sizes since this comes with larger litter heterogenicity, lower litter resilience and risk of higher mortality. Dietary oligosaccharides, given to the sow, proved beneficial for the offspring's performance. However, giving oligosaccharides to the suckling piglet is poorly explored. Therefore, this field trial studied the effect of dietary short-chain fructo-oligosaccharides (scFOS; 1g/day; drenched) supplementation to low (LBW, lower quartile), normal (NBW, two intermediate quartiles) and high (HBW, upper quartile) birth weight piglets from birth until 7 or 21 days of age. Performance parameters, gut microbiome and short-chain fatty acids profile of feces and digesta were assessed at birth (d 0), d 7, weaning (d 21.5) and 2 weeks post-weaning (d 36.5). Additional parameters reflecting gut health (intestinal integrity and morphology, mucosal immune system) were analysed at d 36.5. Most parameters changed with age or differed with the piglet's birth weight. Drenching with scFOS increased body weight by 1 kg in NBW suckling piglets and reduced the post-weaning mortality rate by a 100%. No clear difference in the IgG level, the microbiota composition and fermentative activity between the treatment groups was observed. Additionnally, intestinal integrity, determined by measuring intestinal permeability and regenerative capacity, was similar between the treatment groups. Also, intestinal architecture (villus lenght, crypt depth) was not affected by scFOS supplementation. The density of intra-epithelial lymphocytes and the expression profiles (real-time qPCR) for immune system-related genes (IL-10, IL-1ß, IL-6, TNFα and IFNγ) were used to assess mucosal immunity. Only IFNγ expression, was upregulated in piglets that received scFOS for 7 days. The improved body weight and the reduced post-weaning mortality seen in piglets supplemented with scFOS support the view that scFOS positively impact piglet's health and resilience. However, the modes of action for these effects are not yet fully elucidated and its potential to improve other performance parameters needs further investigation.


Assuntos
Ração Animal , Criação de Animais Domésticos/métodos , Suplementos Nutricionais , Oligossacarídeos/administração & dosagem , Sus scrofa/fisiologia , Fenômenos Fisiológicos da Nutrição Animal/imunologia , Animais , Animais Lactentes/fisiologia , Peso Corporal/fisiologia , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/imunologia , Imunidade nas Mucosas , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Sus scrofa/microbiologia , Desmame
8.
Proc Natl Acad Sci U S A ; 117(27): 15748-15754, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571943

RESUMO

Trade-offs between growth, reproduction, and lifespan constrain animal life histories, leading to evolutionary diversification of life history cycles in different environments. In female mammals, gestation and lactation are expected to impose the major costs of reproduction, driving reproductive trade-offs, although mating also requires interactions with males that could themselves influence life history. Here we show that a male's presence by itself leads to lifelong alterations in life history in female mice. Housing C57BL/6J female mice with sterilized males early in life led to an increase in body weight, an effect that persisted across life even when females were later allowed to produce pups. We found that those females previously housed with sterile males also showed enhanced late-life offspring production when allowed to reproduce, indicating that earlier mating can influence subsequent fecundity. This effect was the opposite to that seen in females previously housed with intact males, which showed the expected trade-off between early-life and late-life reproduction. However, housing with a sterile male early in life came at a cost to lifespan, which was observed in the absence of females ever undergoing fertilization. Endocrinologically, mating also permanently reduced the concentration of circulating prolactin, a pituitary hormone influencing maternal care. Changes in hormone axes that influence reproduction could therefore help alter life history allocation in response to opposite-sex stimuli. Our results demonstrate that mating itself can increase growth and subsequent fecundity in mammals, and that responses to sexual stimuli could account for some lifespan trade-offs normally attributed to pregnancy and lactation.


Assuntos
Evolução Biológica , Fertilidade/fisiologia , Longevidade/fisiologia , Reprodução/fisiologia , Animais , Fenômenos Biológicos , Peso Corporal/genética , Peso Corporal/fisiologia , Comunicação Celular , Feminino , Fertilidade/genética , Infertilidade Masculina/genética , Lactação , Longevidade/genética , Masculino , Camundongos , Reprodução/genética , Comportamento Sexual Animal/fisiologia
9.
Am J Physiol Regul Integr Comp Physiol ; 319(2): R171-R183, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32551825

RESUMO

Exercise is often used as a strategy for weight loss maintenance. In preclinical models, we have shown that exercise may be beneficial because it counters the biological drive to regain weight. However, our studies have demonstrated sex differences in the response to exercise in this context. In the present study, we sought to better understand why females and males exhibit different compensatory food eating behaviors in response to regular exercise. Using a forced treadmill exercise paradigm, we measured weight gain, energy expenditure, food intake in real time, and the anorectic effects of leptin. The 4-wk exercise training resulted in reduced weight gain in males and sustained weight gain in females. In male rats, exercise decreased intake, whereas it increased food intake in females. Our results suggest that the anorectic effects of leptin were not responsible for these sex differences in appetite in response to exercise. If these results translate to the human condition, they may reveal important information for the use and application of regular exercise programs.


Assuntos
Apetite/fisiologia , Peso Corporal/fisiologia , Ingestão de Alimentos/fisiologia , Metabolismo Energético/fisiologia , Condicionamento Físico Animal/fisiologia , Animais , Ingestão de Energia/fisiologia , Feminino , Masculino , Ratos
10.
PLoS One ; 15(6): e0235063, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574192

RESUMO

BACKGROUND: Adolescent overweight and obesity is a global public health problem, associated with an increased risk of metabolic syndrome. Recently, mid-upper arm circumference (MUAC) has been suggested as a screening tool to identify overweight and obesity among school-age children and early adolescents (5-14 years). However, little is known about the potential use of MUAC in the late adolescence period (15-19 years). Therefore, the present study aimed to evaluate the performance of MUAC to identify overweight (including obesity) in the late adolescence period in Ethiopia. METHODS: We conducted a cross-sectional study among 851 adolescents aged 15 to 19 years. We collected anthropometric data including MUAC, weight and height with the help of trained field workers. The receiver operating characteristic (ROC) curve analysis was used to examine the validity of MUAC compared to BMI Z score in identifying adolescents with overweight or obesity. Furthermore, we calculated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), proportion of correctly classified, positive, and negative likelihood ratio for the proposed optimal cut-offs. RESULTS: MUAC was strongly correlated with BMI Z score with a correlation coefficient (r) of 0.81 (95% CI; 0.79-0.84). The optimal MUAC cut-off for identifying adolescents with overweight or obesity was 27.7 cm for males and 27.9 cm for females. The area under the ROC curve (AUC) was 0.96 (95% CI; 0.93-0.98) for males and 0.96 (95% CI; 0.94-0.98) for females. The accuracy level of MUAC to identify adolescents with overweight (including obesity) was high for both sexes (overall a sensitivity of 91.1% and a specificity of 90.3%). CONCLUSIONS: MUAC has relatively equivalent accuracy with BMI Z score to identify overweight and obesity in adolescents. Hence, MUAC could be used as an alternative tool for surveillance and screening of overweight in adolescents aged 15-19 years.


Assuntos
Braço/anatomia & histologia , Índice de Massa Corporal , Peso Corporal/fisiologia , Programas de Rastreamento/métodos , Obesidade Pediátrica/diagnóstico , Adolescente , Antropometria/métodos , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Masculino , Curva ROC , Adulto Jovem
11.
PLoS One ; 15(6): e0235140, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574203

RESUMO

BACKGROUND: Due to improved treatment, there is an increasing focus on the reproductive potential of survivors of childhood cancer. Cytotoxic chemotherapy accelerates the decline in the number of primordial follicles within the mammalian ovary at all ages, but effects on the developmental potential of remaining oocytes following prepubertal cancer treatment are unclear. OBJECTIVES: To investigate whether cyclophosphamide (CY) exposure in the prepubertal period in female mice influences ovarian function and the functional competence of oocytes in adulthood. METHODS: This study used Swiss albino mice as the experimental model. Female mice were treated with 200 mg/kg CY on either postnatal day 14 (CY14), 21 (CY21) or 28 (CY28) i.e at a prepubertal and 2 young postpubertal ages. At 14 weeks of life, ovarian function, functional competence of oocytes, and embryo quality were assessed. RESULTS: The number of primordial follicles decreased significantly in CY14 and CY21 groups compared to control (p < 0.01). The number of oocytes from superovulated was 8.5 ± 1.4, 24.1 ± 2.9 and 26.8 ± 2.1 in CY14, CY21 and CY28 respectively which was significantly lower than control (50.2 ± 3.2; p < 0.001). In vitro culture of CY14 embryos demonstrated only 55.4% blastocyst formation (p < 0.0001) and reduced ability of inner cell mass (ICM) to proliferate in vitro (p < 0.05) at 120 and 216 h post insemination respectively. On the other hand, ICM proliferation was unaltered in 2 young postpubertal ages. CONCLUSION: Our results indicate long-term effects on the developmental competence of oocytes exposed to CY in early but not adult life. These data provide a mechanism whereby long-term fertility can be impaired after chemotherapy exposure, despite the continuing presence of follicles within the ovary, and support the need for fertility preservation in prepubertal girls before alkylating agent exposure.


Assuntos
Blastocisto/efeitos dos fármacos , Ciclofosfamida/farmacologia , Desenvolvimento Embrionário/efeitos dos fármacos , Reserva Ovariana/efeitos dos fármacos , Maturidade Sexual/fisiologia , Animais , Hormônio Antimülleriano/sangue , Antineoplásicos Alquilantes/farmacologia , Blastocisto/citologia , Blastocisto/fisiologia , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Proliferação de Células/efeitos dos fármacos , Ciclofosfamida/administração & dosagem , Embrião de Mamíferos/efeitos dos fármacos , Embrião de Mamíferos/embriologia , Desenvolvimento Embrionário/fisiologia , Feminino , Fertilidade/efeitos dos fármacos , Fertilidade/fisiologia , Camundongos , Oócitos/efeitos dos fármacos , Oócitos/fisiologia , Tamanho do Órgão/efeitos dos fármacos , Reserva Ovariana/fisiologia , Ovário/anatomia & histologia , Ovário/citologia , Ovário/efeitos dos fármacos , Fatores de Tempo
12.
PLoS One ; 15(6): e0235144, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32579613

RESUMO

BACKGROUND: Commercial physical activity monitors have wide utility in the assessment of physical activity in research and clinical settings, however, the removal of devices results in missing data and has the potential to bias study conclusions. This study aimed to evaluate methods to address missingness in data collected from commercial activity monitors. METHODS: This study utilised 1526 days of near complete data from 109 adults participating in a European weight loss maintenance study (NoHoW). We conducted simulation experiments to test a novel scaling methodology (NoHoW method) and alternative imputation strategies (overall/individual mean imputation, overall/individual multiple imputation, Kalman imputation and random forest imputation). Methods were compared for hourly, daily and 14-day physical activity estimates for steps, total daily energy expenditure (TDEE) and time in physical activity categories. In a second simulation study, individual multiple imputation, Kalman imputation and the NoHoW method were tested at different positions and quantities of missingness. Equivalence testing and root mean squared error (RMSE) were used to evaluate the ability of each of the strategies relative to the true data. RESULTS: The NoHoW method, Kalman imputation and multiple imputation methods remained statistically equivalent (p<0.05) for all physical activity metrics at the 14-day level. In the second simulation study, RMSE tended to increase with increased missingness. Multiple imputation showed the smallest RMSE for Steps and TDEE at lower levels of missingness (<19%) and the Kalman and NoHoW methods were generally superior for imputing time in physical activity categories. CONCLUSION: Individual centred imputation approaches (NoHoW method, Kalman imputation and individual Multiple imputation) offer an effective means to reduce the biases associated with missing data from activity monitors and maximise data retention.


Assuntos
Exercício Físico/fisiologia , Monitores de Aptidão Física/estatística & dados numéricos , Monitorização Fisiológica/estatística & dados numéricos , Projetos de Pesquisa/estatística & dados numéricos , Adulto , Idoso , Algoritmos , Viés , Peso Corporal/fisiologia , Simulação por Computador , Metabolismo Energético/fisiologia , Feminino , Monitores de Aptidão Física/normas , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Projetos de Pesquisa/normas , Perda de Peso/fisiologia , Adulto Jovem
13.
PLoS One ; 15(4): e0232221, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32353035

RESUMO

BACKGROUND: Some guidelines state that in-person weight management interventions are more efficacious than those delivered digitally. However, digital programs are more scalable and accessible. We hypothesized that one-on-one health coaching via app-based video chat would simulate an in-person experience and help achieve outcomes comparable to those of in-person interventions. METHODS: A 12-month digital weight management intervention was provided to overweight or obese adults recruited from a large technology company. One-on-one health coaching sessions were offered during a 24-week intensive phase as well as subsequent maintenance phase. Focused on sustainable changes in activity and diet, the intervention incorporates SMART goals, in-app food and activity logs, Fitbit integration, as well as optional sleep and stress modules. Self-Determination Theory and the Transtheoretical Model are incorporated to drive behavior change. Multilevel mixed-effects models were used to analyze weight changes retrospectively. RESULTS: Six hundred eighty-three participants reported 29,051 weights. At 12 months, mean percent changes in body weight were -7.2% and -7.6% for overweight and obese groups, respectively. A weight change of -5% is commonly targeted for in-person weight management interventions. Observed weight loss exceeded this target by 2.2% (95% CI, 0.7% to 3.8%; P < .01) for the overweight group and 2.6% (95% CI, 1.4% to 3.9%; P < .01) for the obese group. CONCLUSIONS: Further research is needed with randomization to in-person or digital interventions. Though limited by an observational, retrospective design, preliminary results suggest that some digital weight management programs with one-on-one coaching may achieve outcomes comparable to those of robust, in-person interventions.


Assuntos
Peso Corporal/fisiologia , Adulto , Dieta , Exercício Físico/fisiologia , Feminino , Humanos , Masculino , Tutoria/métodos , Aplicativos Móveis , Obesidade/fisiopatologia , Estudos Retrospectivos
14.
PLoS Med ; 17(5): e1003122, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32453739

RESUMO

BACKGROUND: Nutritional supplements may improve short-term growth of infants born small (preterm or small for gestational age), but there are few data on long-term effects and concerns that body composition may be adversely affected. Effects also may differ between girls and boys. Our systematic review and meta-analysis assessed the effects of macronutrient supplements for infants born small on later growth. METHODS AND FINDINGS: We searched OvidMedline, Embase, Cochrane CENTRAL, and Cochrane Database of Systematic Reviews from inception to January 30, 2020, and controlled-trials.com, clinicaltrials.gov, and anzctr.org.au on January 30, 2020. Randomised or quasirandomised trials were included if the intention was to increase macronutrient intake to improve growth or development of infants born small and growth was assessed after discharge. Primary outcome was body mass index (BMI) in childhood. Data were pooled using random-effect models. Outcomes were evaluated in toddlers (< 3 years), childhood (3 to 8 years), adolescence (9 to 18 years), and adulthood (>18 years). Forty randomised and 2 quasirandomised trials of variable methodological quality with 4,352 infants were included. Supplementation did not alter BMI in childhood (7 trials, 1,136 children; mean difference [MD] -0.10 kg/m2, [95% confidence interval (CI) -0.37 to 0.16], p = 0.45). In toddlers, supplementation increased weight (31 trials, 2,924 toddlers; MD 0.16 kg, [0.01 to 0.30], p = 0.03) and length/height (30 trials, 2,889 toddlers; MD 0.44 cm, [0.10 to 0.77], p = 0.01), but not head circumference (29 trials, 2,797 toddlers; MD 0.15 cm, [-0.03 to 0.33], p = 0.10). In childhood, there were no significant differences between groups in height (7 trials, 1,136 children; MD 0.22 cm, [-0.48 to 0.92], p = 0.54) or lean mass (3 trials, 354 children; MD -0.07 kg, [-0.98 to 0.85], p = 0.88), although supplemented children appeared to have higher fat mass (2 trials, 201 children; MD 0.79 kg, [0.19 to 1.38], p = 0.01). In adolescence, there were no significant differences between groups in BMI (2 trials, 216 adolescents; MD -0.48 kg/m2, [-2.05 to 1.08], p = 0.60), height (2 trials, 216 adolescents; MD -0.55 cm, [-2.95 to 1.86], p = 0.65), or fat mass (2 trials, 216 adolescents; MD -1.3 5 kg, [-5.76 to 3.06], p = 0.55). In adulthood, there also were no significant differences between groups in weight z-score (2 trials, 199 adults; MD -0.11, [-0.72 to 0.50], p = 0.73) and height z-score (2 trials, 199 adults; MD -0.07, [-0.36 to 0.22], p = 0.62). In subgroup analysis, supplementation was associated with increased length/height in toddler boys (2 trials, 173 boys; MD 1.66 cm, [0.75 to 2.58], p = 0.0003), but not girls (2 trials, 159 girls; MD 0.15 cm, [-0.71 to 1.01], p = 0.74). Limitations include considerable unexplained heterogeneity, low to very low quality of evidence, and possible bias due to low or unbalanced followup. CONCLUSIONS: In this systematic review and meta-analysis, we found no evidence that early macronutrient supplementation for infants born small altered BMI in childhood. Although supplements appeared to increase weight and length in toddlers, effects were inconsistent and unlikely to be clinically significant. Limited data suggested that supplementation increased fat mass in childhood, but these effects did not persist in later life. PROSPERO registration: CRD42019126918.


Assuntos
Suplementos Nutricionais , Fenômenos Fisiológicos da Nutrição do Lactente/fisiologia , Recém-Nascido Pequeno para a Idade Gestacional/crescimento & desenvolvimento , Nutrientes/metabolismo , Adolescente , Adulto , Peso Corporal/fisiologia , Criança , Ingestão de Energia/fisiologia , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro/crescimento & desenvolvimento , Parto/fisiologia , Gravidez
15.
PLoS One ; 15(5): e0233134, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407361

RESUMO

BACKGROUND: The importance of concurrent exercise order for improving endurance and resistance adaptations remains unclear, particularly when sessions are performed a few hours apart. We investigated the effects of concurrent training (in alternate orders, separated by ~3 hours) on endurance and resistance training adaptations, compared to resistance-only training. MATERIALS AND METHODS: Twenty-nine healthy, moderately-active men (mean ± SD; age 24.5 ± 4.7 y; body mass 74.9 ± 10.8 kg; height 179.7 ± 6.5 cm) performed either resistance-only training (RT, n = 9), or same-day concurrent training whereby high-intensity interval training was performed either 3 hours before (HIIT+RT, n = 10) or after resistance training (RT+HIIT, n = 10), for 3 d.wk-1 over 9 weeks. Training-induced changes in leg press 1-repetition maximal (1-RM) strength, countermovement jump (CMJ) performance, body composition, peak oxygen uptake ([Formula: see text]), aerobic power ([Formula: see text]), and lactate threshold ([Formula: see text]) were assessed before, and after both 5 and 9 weeks of training. RESULTS: After 9 weeks, all training groups increased leg press 1-RM (~24-28%) and total lean mass (~3-4%), with no clear differences between groups. Both concurrent groups elicited similar small-to-moderate improvements in all markers of aerobic fitness ([Formula: see text] ~8-9%; [Formula: see text] ~16-20%; [Formula: see text] ~14-15%). RT improved CMJ displacement (mean ± SD, 5.3 ± 6.3%), velocity (2.2 ± 2.7%), force (absolute: 10.1 ± 10.1%), and power (absolute: 9.8 ± 7.6%; relative: 6.0 ± 6.6%). HIIT+RT elicited comparable improvements in CMJ velocity only (2.2 ± 2.7%). Compared to RT, RT+HIIT attenuated CMJ displacement (mean difference ± 90%CI, -5.1 ± 4.3%), force (absolute: -8.2 ± 7.1%) and power (absolute: -6.0 ± 4.7%). Only RT+HIIT reduced absolute fat mass (mean ± SD, -11.0 ± 11.7%). CONCLUSIONS: In moderately-active males, concurrent training, regardless of the exercise order, presents a viable strategy to improve lower-body maximal strength and total lean mass comparably to resistance-only training, whilst also improving indices of aerobic fitness. However, improvements in CMJ displacement, force, and power were attenuated when RT was performed before HIIT, and as such, exercise order may be an important consideration when designing training programs in which the goal is to improve lower-body power.


Assuntos
Peso Corporal/fisiologia , Exercício Físico/fisiologia , Força Muscular/fisiologia , Aptidão Física/fisiologia , Treinamento de Resistência , Adulto , Composição Corporal/fisiologia , Humanos , Masculino , Atividade Motora/fisiologia
16.
Rev Assoc Med Bras (1992) ; 66(2): 222-226, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32428159

RESUMO

OBJECTIVE: To verify the relationship of intermittent fasting in the bodyweight of overweight and obese individuals through a systematic literature review. METHODS: This is a systematic review based on randomized controlled trials. The articles were consulted in the databases: Science Direct, PubMed e BVS. This review was evaluated through the PRISMA recommendation. RESULTS: After the selection process, four articles were included in this review, comparing intermittent fasting (IF) with calorie restriction diet (CRD) as a control group. In 2 studies using similar protocols, there was no significant reduction in body weight of overweight or obese subjects. In the other two studies using different protocols, weight loss was significant in the IF group compared to the CRD group. CONCLUSIONS: Results did not provide evidence of the effect of intermittent fasting on weight loss in overweight or obese individuals.


Assuntos
Peso Corporal/fisiologia , Jejum/fisiologia , Obesidade/dietoterapia , Sobrepeso/dietoterapia , Perda de Peso/fisiologia , Restrição Calórica/métodos , Dieta Redutora/métodos , Humanos , Obesidade/metabolismo , Sobrepeso/metabolismo , Resultado do Tratamento
17.
Lancet Diabetes Endocrinol ; 8(6): 477-489, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32445735

RESUMO

BACKGROUND: Type 2 diabetes is affecting people at an increasingly younger age, particularly in the Middle East and in north Africa. We aimed to assess whether an intensive lifestyle intervention would lead to significant weight loss and improved glycaemia in young individuals with early diabetes. METHODS: This open-label, parallel-group, randomised controlled trial (DIADEM-I), done in primary care and community settings in Qatar, compared the effects of an intensive lifestyle intervention with usual medical care on weight loss and glycaemic outcomes in individuals with type 2 diabetes, aged 18-50 years, with a short diabetes duration (≤3 years), had a BMI of 27·0 kg/m2 or more, and who were from the Middle East and north Africa region. Participants were randomly allocated (1:1) either to the intensive lifestyle intervention group or the usual medical care control group by a computer-generated sequence and an online randomisation service. The intensive lifestyle intervention comprised a total diet replacement phase, in which participants were given formula low-energy diet meal replacement products followed by gradual food reintroduction combined with physical activity support, and a weight-loss maintenance phase, involving structured lifestyle support. Participants in the control group received usual diabetes care, which was based on clinical guidelines. The primary outcome was weight loss at 12 months after receiving the assigned intervention. Our analysis was based on the intention-to-treat principle. Key secondary outcomes included diabetes control and remission. The trial was registered with the ISRCTN registry, ISRCTN20754766, and ClinicalTrials.gov, NCT03225339. FINDINGS: Between July 16, 2017, and Sept 30, 2018, we enrolled and randomly assigned 158 participants (n=79 in each group) to the study. 147 participants (70 in the intervention group and 77 in the control group) were included in the final intention-to-treat analysis population. Between baseline and 12 months, the mean bodyweight of participants in the intervention group reduced by 11·98 kg (95% CI 9·72 to 14·23) compared with 3·98 kg (2·78 to 5·18) in the control group (adjusted mean difference -6·08 kg [95% CI -8·37 to -3·79], p<0·0001). In the intervention group, 21% of participants achieved more than 15% weight loss between baseline and 12 months compared with 1% of participants in the control group (p<0·0001). Diabetes remission occurred in 61% of participants in the intervention group compared with 12% of those in the control group (odds ratio [OR] 12·03 [95% CI 5·17 to 28·03], p<0·0001). 33% of participants in the intervention group had normoglycaemia compared with 4% of participants in the control group (OR 12·07 [3·43 to 42·45], p<0·0001). Five serious adverse events were reported in four participants in the control group; four admissions to hospital because of unanticipated events (supraventricular tachycardia, abdominal pain, pneumonia, and epididymo-orchitis), and one admission to hospital for an anticipanted event (hyperglycaemia). INTERPRETATION: Our findings show that the intensive lifestyle intervention led to significant weight loss at 12 months, and was associated with diabetes remission in over 60% of participants and normoglycaemia in over 30% of participants. The provision of this lifestyle intervention could allow a large proportion of young individuals with early diabetes to achieve improvements in key cardiometabolic outcomes, with potential long-term benefits for health and wellbeing. FUNDING: Qatar National Research Fund.


Assuntos
Glicemia/metabolismo , Peso Corporal/fisiologia , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/terapia , Índice Glicêmico/fisiologia , Comportamento de Redução do Risco , Adolescente , Adulto , África do Norte/epidemiologia , Diabetes Mellitus Tipo 2/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oriente Médio/epidemiologia , Resultado do Tratamento , Perda de Peso/fisiologia , Adulto Jovem
18.
J Headache Pain ; 21(1): 45, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375641

RESUMO

BACKGROUND: Pain is a common symptom, often associated with neurological and musculoskeletal conditions, and experienced especially by females and by older people, and with increasing trends in general populations. Different risk factors for pain have been identified, but generally from studies with limited samples and a limited number of candidate predictors. The aim of this study is to evaluate the predictors of pain from a large set of variables and respondents. METHODS: We used part of the harmonized dataset of ATHLOS project, selecting studies and waves with a longitudinal course, and in which pain was absent at baseline and with no missing at follow-up. Predictors were selected based on missing distribution and univariable association with pain, and were selected from the following domains: Socio-demographic and economic characteristics, Lifestyle and health behaviours, Health status and functional limitations, Diseases, Physical measures, Cognition, personality and other psychological measures, and Social environment. Hierarchical logistic regression models were then applied to identify significant predictors. RESULTS: A total of 13,545 subjects were included of whom 5348 (39.5%) developed pain between baseline and the average 5.2 years' follow-up. Baseline risk factors for pain were female gender (OR 1.34), engaging in vigorous exercise (OR 2.51), being obese (OR 1.36) and suffering from the loss of a close person (OR 1.88) whereas follow-up risk factors were low energy levels/fatigue (1.93), difficulties with walking (1.69), self-rated health referred as poor (OR 2.20) or average to moderate (OR 1.57) and presence of sleep problems (1.80). CONCLUSIONS: Our results showed that 39.5% of respondents developed pain over a five-year follow-up period, that there are proximal and distal risk factors for pain, and that part of them are directly modifiable. Actions aimed at improving sleep, reducing weight among obese people and treating fatigue would positively impact on pain onset, and avoiding vigorous exercise should be advised to people aged 60 or over, in particular if female or obese.


Assuntos
Envelhecimento/fisiologia , Bases de Dados Factuais/tendências , Dor/diagnóstico , Dor/epidemiologia , Vigilância da População , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/patologia , Peso Corporal/fisiologia , China/epidemiologia , Cognição/fisiologia , Europa (Continente)/epidemiologia , Exercício Físico/fisiologia , Feminino , Seguimentos , Nível de Saúde , Humanos , Estilo de Vida , Estudos Longitudinais , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Dor/fisiopatologia , Vigilância da População/métodos , Valor Preditivo dos Testes , Fatores de Risco , Fatores Sexuais , Adulto Jovem
19.
Obesity (Silver Spring) ; 28(7): 1301-1309, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32447840

RESUMO

OBJECTIVE: This study aimed to examine the associations of overweight and obesity (ov/ob) and changes in weight status with academic performance among Chinese adolescents. METHODS: Self-reported weight and height were collected from adolescents (n = 10,279) each year from seventh grade (baseline, 2013-2014) to ninth grade (2015-2016). Academic performance included standardized scores on math, Chinese, and English examinations and responses to a school-life experience scale. RESULTS: All adolescents with ov/ob had lower academic performance than their counterparts without overweight (ß = -0.46 to -0.08; P < 0.05), except for school-life experience for boys. All adolescents with obesity had lower academic performance than their counterparts without obesity (ß = -0.46 to -0.17; P < 0.01), except for English test scores for boys. Changes in weight status between grades 7 and 9 impacted academic performance at grade 9. Adolescents with ov/ob throughout grades 7 to 9 and those who developed ov/ob from normal weight had lower test scores (ß = -0.80 to -0.25; P < 0.05) than those who maintained normal weight. Those who developed ov/ob after having normal weight had poorer school-life experiences (ß = -0.55 to -0.25; P < 0.05). CONCLUSIONS: Ov/ob and maintaining and developing ov/ob had adverse academic impacts on adolescents. Relevant stakeholders should consider detrimental impacts of obesity on academic outcomes.


Assuntos
Desempenho Acadêmico/estatística & dados numéricos , Sobrepeso/epidemiologia , Obesidade Pediátrica/epidemiologia , Desempenho Acadêmico/psicologia , Adolescente , Peso Corporal/fisiologia , Criança , China/epidemiologia , Estudos de Coortes , Escolaridade , Feminino , Humanos , Masculino , Matemática , Sobrepeso/psicologia , Obesidade Pediátrica/psicologia , Psicologia do Adolescente
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