RESUMO
Long-chain fatty acid (LCFA) movement into skeletal muscle involves a highly mediated process in which lipid rafts are utilized in the cellular membrane, involving numerous putative plasma membrane-associated LCFA transport proteins. The process of LCFA uptake and oxidation is of particular metabolic significance both at rest and during light to moderate exercise. A comprehensive systematic search of electronic databases was conducted to investigate whether exercise alters protein and/or gene expression of putative LCFA transport proteins. There were 31 studies meeting all eligibility criteria, of these 13 utilized an acute exercise protocol and 18 examined chronic exercise adaptations. Seventeen involved a study design incorporating an exercise stimulus, while the remaining 14 incorporated a combined exercise and diet stimulus. Divergent data relating to acute exercise, as well as prolonged exercise training (≥3 weeks), on protein content (PC) response was identified for proteins CD36, FABPpm and CAV1. Messenger ribonucleic acid (mRNA) data did not always correspond to functional PC, supporting previous suggestions of a disconnect due to potentially limiting factors post gene expression. The large array of study designs, cohorts, and primary dependent variables within the studies included in the present review elucidate the complexity of the interaction between exercise and LCFA transport proteins. Summary of the results in the present review validate the need for further targeted investigation within this topic, and provide an important information base for such research. J. Cell. Physiol. 231: 1671-1687, 2016. © 2015 Wiley Periodicals, Inc.
Assuntos
Exercício Físico/fisiologia , Proteínas de Transporte de Ácido Graxo/metabolismo , Ácidos Graxos/metabolismo , Contração Muscular , Músculo Esquelético/metabolismo , Proteínas de Transporte de Ácido Graxo/genética , Regulação da Expressão Gênica , Humanos , RNA Mensageiro/metabolismo , Transdução de Sinais , Fatores de TempoRESUMO
The claim that non-nutritive sweeteners accelerate body weight gain by disrupting sweet-calorie associations was tested in two experiments using rats. The experiments were modelled on a key study from a series of experiments reporting greater body weight gain in rats fed yoghurt sweetened with saccharin than with glucose (Swithers & Davidson, 2008). Both of the current experiments likewise compared groups fed saccharin- or glucose-sweetened yoghurt in addition to chow and water, while Experiment 1 included a third group (Control) given unsweetened yoghurt. In Experiment 1, but not in Experiment 2, rats were initially exposed to both saccharin- and glucose-sweetened yoghurts to assess their relative palatability. We also tested whether the provision of an energy-dense sweet biscuit would augment any effects of saccharin on food intake and weight gain, as seemingly predicted by Swithers and Davidson (2008). In Experiment 1 there were no differences in body weight gain or fat pad mass between the Saccharin and Control group, whereas the Glucose group was the heaviest by the final 5 weeks and at cull had the largest fat pads. Greater acceptance of saccharin predicted more weight gain over the whole experiment. Consistent with past reports, fasting blood glucose and insulin measures did not differ between the Saccharin and Control groups, but suggested some impairment of insulin sensitivity in the Glucose group. Experiment 2 found similar effects of glucose on fat mass, but not on body weight gain. In summary, adding saccharin had no detectable effects on body-weight regulation, whereas the effects of glucose on fat pad mass were consistent with previous studies reporting more harmful effects of sugars compared to non-nutritive sweeteners.
Assuntos
Adiposidade , Glucose/efeitos adversos , Adoçantes não Calóricos/efeitos adversos , Adoçantes Calóricos/efeitos adversos , Sobrepeso/etiologia , Sacarina/efeitos adversos , Iogurte/efeitos adversos , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Animais , Ingestão de Energia , Feminino , Preferências Alimentares , Humanos , Resistência à Insulina , Masculino , Sobrepeso/metabolismo , Sobrepeso/patologia , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Fatores de Tempo , Aumento de PesoRESUMO
Throwing velocity is an important aspect of fielding in cricket to affect run-outs and reduce the opponent's run-scoring opportunities. Although a relationship between strength and/or power and throwing velocity has been well established in baseball, water polo, and European handball, it has not been adequately explored in cricket. Consequently, this study aimed to determine the relationship between measures of strength and/or power and throwing velocity in cricket players. Seventeen male cricket players (mean ± SD; age, 21.1 ± 1.6 years; height, 1.79 ± 0.06 m; weight, 79.8 ± 6.4 kg) from an elite athlete program were tested for maximal throwing velocity from the stretch position and after a 3-meter shuffle. They were also assessed for strength and power using a range of different measures. Throwing velocity from the stretch position (30.5 ± 2.4 m·s) was significantly related to dominant leg lateral-to-medial jump (LMJ) distance (r = 0.71; p < 0.01), dominant shoulder internal rotation (IR) strength (r = 0.55; p ≤ 0.05), and dominant (r = 0.73; p < 0.01) and nondominant (r = 0.54; p ≤ 0.05) medicine ball rotation (MB Rot) throw velocity and medicine ball chest pass (MB CP) distance (r = 0.67; p < 0.01). A nonsignificant trend was observed for vertical jump (VJ) height (p = 0.06), whereas no significant relationships were observed for nondominant LMJ distance (p = 0.97), nondominant shoulder IR strength (p = 0.80), 1 repetition maximum (RM) squat strength (p = 0.57), 1RM bench press strength (p = 0.90), height (p = 0.33), or weight (p = 0.29). Multiple regression analysis revealed that dominant MB Rot and MB CP explained 66% of the variance. The results were similar for velocity after a shuffle step (31.8 ± 2.1 m·s); however, VJ height reached statistical significance (r = 0.51; p ≤ 0.05). The multiple regression was also similar with MB Rot and MB CP explaining 70% of the variance. The cricketers in this study threw with greater velocity than elite junior and subelite senior cricketers but with lower velocities than elite senior cricketers and collegiate level and professional baseball players. This is the first study to demonstrate a link between strength and/or power and throwing velocity in cricket players and highlight the importance of power development as it relates to throwing velocity. Exercises that more closely simulated the speed (body weight jumps and medicine ball throws) or movement pattern (shoulder IR) of overhead throwing were greater predictors of throwing velocity. Strength and conditioning staff should assess and develop power to enhance throwing performance in cricket players. Exercises with greater movement and speed specificity to throwing should be used in preference over exercises that are slower and have less movement specificity to the throwing motion. Cricket players should engage in power training to bridge the gap in performance between them and baseball players.
Assuntos
Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Ombro/fisiologia , Esportes/fisiologia , Adulto , Atletas , Estudos Transversais , Humanos , Masculino , Análise de Regressão , Adulto JovemRESUMO
In the context of the well-documented metabolic and behavioural effects of supplementing rats' diets with access to a sucrose solution, the aim of this study was to compare the impact of 10% sucrose with that of an isoenergetic (10.4%) solution of hydrolysed starch, maltodextrin. This polysaccharide is metabolised at least as rapidly as sucrose and is also very palatable to rats, but does not contain fructose. Each of three experiments contained three groups: one given a sucrose solution, one given a maltodextrin solution and a control group maintained on standard chow and water alone. In Experiment 1 the sucrose and maltodextrin groups were given their supplementary drinks for 2 h each day, while in Experiments 2 and 3 these groups had 24-h access to their supplements. Ad libitum access to maltodextrin produced at least as rapid weight gain as sucrose and in Experiment 2 retroperitoneal fat mass was greater in the two carbohydrate groups than in the control group. Moreover, in Experiment 3, impaired performance on a location recognition task was also found in both carbohydrate groups after only 17 days on the diets. These results indicate that the harmful effects of excess sucrose consumption can also be produced by another rapidly absorbed carbohydrate that does not contain fructose.
Assuntos
Tecido Adiposo/efeitos dos fármacos , Cognição/efeitos dos fármacos , Sacarose Alimentar/farmacologia , Ingestão de Energia , Polissacarídeos/farmacologia , Aprendizagem Espacial/efeitos dos fármacos , Aumento de Peso/efeitos dos fármacos , Animais , Sacarose Alimentar/efeitos adversos , Sacarose Alimentar/metabolismo , Frutose/farmacologia , Masculino , Polissacarídeos/efeitos adversos , Polissacarídeos/metabolismo , Ratos WistarRESUMO
There has been intense focus on improving the quality of animal research in recent times. An emerging concept of a 'culture of care' has been proposed as another important pillar to enhance scientific quality, with staff well-being being a critical aspect. Professionals working with research animals can face moral and psychological burdens and are at risk of experiencing work-related stress. However, data on the global prevalence of stress in this population is limited. Equally, it is not clear how these stresses manifest, and what impact they might have on an individual's workplace performance and research quality. The purpose of this review was to identify work-related stress, its prevalence, and map evidence on strategies to mitigate stresses. We also set out to identify studies assessing the association between work-related stress and research quality. A systematic search was conducted across four databases, in addition to hand searching relevant references. We included peer-reviewed publications describing work-related stress, culture of care and laboratory animal professionals. A total of 49 publications were included for data mapping. Compassion fatigue was the most frequently described work-related stress, and its prevalence across Europe and North America is likely to be widespread. Multiple strategies to mitigate compassion fatigue and work-related stress were put forward, however, limited empirical evidence was available to assess success. Moreover, no studies reported empirical data linking work-related stress with research quality, despite several publications stating the case. Further population-specific research and measured assessments are urgently needed to deliver culture of care programmes to improve human well-being, animal welfare and research quality.
RESUMO
BACKGROUND: Consumption of sugar-sweetened beverages (SSBs) forms the primary source of added sugar intake and can increase the risk of metabolic disease. Evidence from studies in humans and rodents also indicates that consumption of SSBs can impair performance on cognitive tests, but that removing SSB access can ameliorate these effects. METHODS: The present study used an unblinded 3-group parallel design to assess the effects of a 12-week intervention in which young healthy adults (mean age = 22.85, SD = 3.89; mean BMI: 23.2, SD = 3.6) who regularly consumed SSBs were instructed to replace SSB intake with artificially-sweetened beverages (n = 28) or water (n = 25), or (c) to continue SSB intake (n = 27). RESULTS: No significant group differences were observed in short-term verbal memory on the Logical Memory test or the ratio of waist circumference to height (primary outcomes), nor in secondary measures of effect, impulsivity, adiposity, or glucose tolerance. One notable change was a significant reduction in liking for strong sucrose solutions in participants who switched to water. Switching from SSBs to 'diet' drinks or water had no detectable impact on cognitive or metabolic health over the relatively short time frame studied here. This study was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615001004550; Universal Trial Number: U1111-1170-4543).
Assuntos
Bebidas Adoçadas com Açúcar , Adulto , Humanos , Adulto Jovem , Adiposidade , Bebidas Adoçadas Artificialmente , Austrália , Bebidas Adoçadas com Açúcar/efeitos adversos , AçúcaresRESUMO
Public interest in low-carbohydrate (LC) diets for type 1 diabetes (T1D) management has increased. This study compared the effects of a healthcare professional delivered LC diet compared to habitual diets higher in carbohydrates on clinical outcomes in adults with T1D. Twenty adults (18-70 yrs) with T1D (≥6 months duration) with suboptimal glycaemic control (HbA1c>7.0% or >53 mmol/mol) participated in a 16-week single arm within-participant, controlled intervention study involving a 4-week control period following their habitual diets (>150 g/day of carbohydrates) and a 12-week intervention period following a LC diet (25-75 g/day of carbohydrates) delivered remotely by a registered dietitian. Glycated haemoglobin (HbA1c -primary outcome), time in range (blood glucose: 3.5-10.0 mmol/L), frequency of hypoglycaemia (<3.5 mmol/L), total daily insulin, and quality of life were assessed before and after the control and intervention periods. Sixteen participants completed the study. During the intervention period, there were reductions in total dietary carbohydrate intake (214 to 63 g/day; P<0.001), HbA1c (7.7 to 7.1% or 61 to 54 mmol/mol; P = 0.003) and total daily insulin use (65 to 49 U/day; P<0.001), increased time spent in range (59 to 74%; P<0.001), and improved quality of life (P = 0.015), with no significant changes observed during the control period. Frequency of hypoglycaemia episodes did not differ across timepoints, and no episodes of ketoacidosis or other adverse events were reported during the intervention period. These preliminary findings suggest that a professionally supported LC diet may lead to improvements in markers of blood glucose control and quality of life with reduced exogenous insulin requirements and no evidence of increased hypoglycaemia or ketoacidosis risk in adults with T1D. Given the potential benefits of this intervention, larger, longer-term randomised controlled trials are warranted to confirm these findings. Trial Registration: https://www.anzctr.org.au/ACTRN12621000764831.aspx.
Assuntos
Diabetes Mellitus Tipo 1 , Hipoglicemia , Cetose , Humanos , Adulto , Diabetes Mellitus Tipo 1/terapia , Hemoglobinas Glicadas , Qualidade de Vida , Dieta com Restrição de Carboidratos , Insulina Regular HumanaRESUMO
During kayak paddling, athletes attempt to maximize kayak velocity with the generation of optimal paddle forces. The aim of the current study was to examine ten elite kayakers and identify a number of key biomechanical performance variables during maximal paddling on a custom kayak simulator. These included analysing the effect of side (left and right) and period (beginning, middle, and end of the kayak simulation) on paddle force, paddle angle, mechanical efficiency, and stroke timing data. Paddle kinetics and kinematics were measured with strain gauge force transducers attached to either end of the ergometer paddle and using a 3D motion analysis system respectively. Results indicated a significantly greater mechanical efficiency during the right paddle stroke compared with the left (P < 0.025). In addition, analysing the effect of period, peak paddle force demonstrated a significant reduction when comparing the beginning to the middle and end of the simulated race respectively (P < 0.025). Examination of individual force profiles revealed considerable individuality, with significant variation in the time course of force application. Analysis of the profiles presented may provide meaningful feedback for kayakers and their coaches.
Assuntos
Braço/fisiologia , Desempenho Atlético/fisiologia , Movimento/fisiologia , Esforço Físico/fisiologia , Navios , Esportes/fisiologia , Análise e Desempenho de Tarefas , Adulto , Fenômenos Biomecânicos , Ergometria , Humanos , Contração Muscular/fisiologia , Adulto JovemRESUMO
Aim: To report the experience of chronic pain participants after a well-formulated ketogenic diet (WFKD) or whole-food diet (WFD). The quantitative outcomes for this trial have been published separately (clinical trial registration number ACTRN12620000946910). Patients & methods: The experience of 24 participants was evaluated after 12 and 24 weeks of dietary intervention using survey responses and open questions. Results & conclusion: Retention rates for the WFKD and WFD groups were 93 and 89%, respectively. Average adherence to the WFKD was 82% and to the WFD was 87%. The WFKD enjoyment was rated at 66 and 81% for the WFD group. The ease of adhering to the diet varied more widely for the WFKD group. Barriers included knowledge integration, time management, navigating social food environments and emotional attachment to eliminated foods. Facilitators included structured support and coaching, and comprehensive learning materials. The WFKD was shown to be a feasible and effective treatment option for chronic pain.
This paper reports the experiences of 24 individuals with chronic pain when undertaking either a whole-food diet or a whole-food ketogenic diet as an intervention for their chronic pain. The diet ran for 12 weeks, and participants were surveyed at the end of the diet and again after another 12 weeks. There was a low dropout rate for both the groups, and participants reported adhering to the diet they were allocated to. Participants in the ketogenic group reported less enjoyment and were more varied in their adherence to the diet; however, the diet was shown to be feasible in this patient population. There were barriers to engaging with the diet including: implementing the rules of the diet, finding the extra time required, eating out and missing high carbohydrate foods. Having good information to follow and someone to coach them assisted participants to successfully implement the diet.
Assuntos
Dor Crônica , Dieta Cetogênica , Dor Crônica/dietoterapia , Humanos , Projetos Piloto , Inquéritos e Questionários , Resultado do TratamentoRESUMO
Consumption of beverages containing around 10% sucrose contributes to worldwide obesity. Studies using rats can increase understanding of the consequences of such consumption. The present experiment aimed to compare male and female rats, first, in terms of cognitive and metabolic impairments produced by excessive intakes of 10% sucrose solution (Stage 1:8 weeks) and, second, with regard to recovery once access to sucrose ceased (Stage 2:4 weeks). All animals had unrestricted access to chow and water throughout. The primary cognitive outcome was performance on a place recognition task. The primary metabolic outcome was retroperitoneal fat pad mass/kg bodyweight at cull, with body weight and glucose tolerance as secondary outcomes. In a 3 × 2 between-subject factorial design the first factor was whether rats had: (1) unlimited access to a 10% sucrose solution and water throughout both stages (Suc-Suc); (2) were switched from sucrose in the 8-week Stage 1 to water only in the 4-week Stage 2 (Suc-Water); or (3) had no access to sucrose in either stage (Water-Water). The second factor was sex. A major metabolic outcome was that of persistent adiposity in both males and females in the Suc-Water condition. As for place recognition, females in the Suc-Suc condition showed greater long-term resistance than males to the impact of excessive sucrose on spatial memory impairment. Overall, few sex differences were found in secondary metabolic outcomes.
Assuntos
Caracteres Sexuais , Sacarose , Animais , Peso Corporal , Cognição , Feminino , Masculino , Obesidade , RatosRESUMO
Much of the global increase in sugar intake is attributable to rising consumption of sugar-sweetened beverages (SSBs). Because people compensate poorly for liquid calories, SSB consumption increases total energy intake, raising the risk of harmful metabolic effects in addition to possible effects of sugars per se. Glucose and fructose, the constituent sugars in sucrose, can exert distinct effects on metabolism and also differ in their satiating properties, suggesting that compensation for the calories in these sugars may also vary. In light of claims that the fructose within sucrose is particularly harmful, the present study compared the effects of giving rats access to either a sucrose or an isoenergetic glucose solution. Adult male rats were fed standard chow and water supplemented with 95 ml of 10% glucose (Glucose group; n = 10), 9% sucrose solution (Sucrose group; n = 10) or water only (Control group; n = 10) daily for 7 weeks. Sugar-fed groups had higher total energy intakes than the Control group, but the extent of this incomplete compensation did not vary between Sucrose and Glucose groups. In a short-term compensation test, sugar groups were less sensitive to the effects of a sweet pre-meal, with no differences between the Glucose and Sucrose groups. Relative to water, both sugars reduced insulin sensitivity after 4 weeks on the diets and elevated fat mass at 7 weeks. Results suggest that sucrose and glucose induce comparable metabolic impairments and alter the homeostatic regulation of food intake even under conditions where daily access is capped.
Assuntos
Resistência à Insulina , Sacarose , Animais , Sacarose Alimentar , Ingestão de Energia , Frutose , Glucose , Masculino , RatosRESUMO
Aim: To explore the reported diet of Australians with chronic pain and their perceived role of food within their pain experience. Methods: A cross-sectional study of 50 participants reporting chronic pain was undertaken using pain and nutritional questionnaires as well as anthropometric measures. Results: Participants rated their diet between 'good' and 'excellent' (76%) and one that promoted well-being (62%), however 74% were overweight or obese (average BMI 30) with multiple co-morbidities. There was no correlation between measures of dietary adherence and knowledge with reported pain. Conclusion: Participants generally reported their diets to be good, however, this was not reflected in their habitual diet. There was a low perceived role of food altering pain perception.
Assuntos
Dor Crônica/etiologia , Dieta/efeitos adversos , Conhecimentos, Atitudes e Prática em Saúde , Sobrepeso/etiologia , Austrália/epidemiologia , Dor Crônica/epidemiologia , Comorbidade , Estudos Transversais , Dieta/estatística & dados numéricos , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Obesidade/etiologia , Sobrepeso/epidemiologiaRESUMO
Rats first given 24-h access to 10% sucrose for 4 or 12 days (Stage 1) were then switched to a saccharin solution for a 12-day Stage 2. The initial result of this switch was that these Sucrose groups drank less saccharin than Water groups that had been given only water to drink in Stage 1. This difference was maintained throughout Stage 2 by the females that served in Experiments 1 and 4 and by the males that served in Experiment 3. Experiment 1 also found that access to 10% glucose in Stage 1 produced an essentially identical decrease in subsequent saccharin acceptance as that produced by giving 10% sucrose in Stage 1. The impact on subsequent acceptance of saccharin was also tested in rats given two types of maltodextrin solution. The first type of maltodextrin (Myopure brand) was used with the males in Experiment 2; this failed to find any difference between the Maltodextrin and the Water group. However, when a second type of maltodextrin (SolCarb brand) was given to males in Stage 1 of Experiment 3, the results for this group were similar to those from a group given sucrose in Stage 1. The final experiment confirmed that prior exposure to maltodextrin solutions can reduce saccharin acceptance by female rats. Overall, the results suggest that acceptance of saccharin is sensitive to a contrast effect, in that it is reduced by prior exposure to a solution that is more palatable but not necessarily sweet.
Assuntos
Sacarina , Sacarose , Animais , Feminino , Glucose , Masculino , Ratos , Soluções , PaladarRESUMO
Successful kayak paddling requires a powerful and skilful paddler with an appropriately designed kayak and blade to effectively maximize power to provide forward propulsion and minimize negative drag forces. With a greater understanding of the biomechanical properties and design characteristics of kayaking, coaches and athletes can work towards successful paddling performances. Examination of what is occurring biomechanically under the stress of competition is an important step in improving race times. Since the introduction of kayaking as a sport, an increase in the understanding and research behind the biomechanics of flatwater kayaking has, in part, contributed to improved race times. This information may aid coaches in the development of more specific training programmes for their athletes. It is the purpose of this paper to review previous literature regarding the biomechanical principles of flatwater kayaking and certain design modifications in the context of its application to improving paddling performance.
Assuntos
Desempenho Atlético/fisiologia , Navios , Equipamentos Esportivos , Fenômenos Biomecânicos , Eficiência/fisiologia , Desenho de Equipamento , Humanos , Masculino , Fenômenos Mecânicos , Modelos Biológicos , Navios/instrumentaçãoRESUMO
Flat-water kayaking is one of the best-known competitive canoeing disciplines in Australia and across the European countries. From a stationary start, paddlers are required to paddle their kayaks with maximal effort along the length of the competing distance. The ultimate criterion of kayak performance is the time taken to paddle a designated competition distance. In flat-water racing, events are contested over 500 and 1000 metres. To approximate the ultimate criterion over these distances, the velocity of the kayak should be measured. Furthermore, other factors that affect performance, such as force, power, technique and aerobic fitness, would all provide a valuable insight to the success of the kayak paddler. Specific research performed examining the physiological demands on kayak paddlers demonstrate high levels of both aerobic power and anaerobic capacity. It is the purpose if this review to present the published physiological data relating to men's and women's kayaking. With a number of recent publications, a need for an updated review is necessary. The present review summarises recent data on anthropometrics, physiological characteristics of successful and unsuccessful kayak athletes and methods of physiological testing. Due to the fact that more data have been reported for male competitors than for their female counterparts, the demands of kayaking on male athletes will be the main focus for this review. The review also suggests areas for future research into flatwater kayaking performance. Understanding the physiological requirements of kayaking can assist coaches and athletes in a number of ways. During competition or training, such information is helpful in the selection of appropriate protocols and metabolic indices to monitor an athlete's performance improvements and assess an athlete's suitability for a particular race distance. Furthermore, it may aid the coach in the development of more specific training programs for their athletes. Key pointsFlat water kayaking is characterised by exceptional demands on upper body performance.When examining the oxygen consumption, it is notable that although a high value is attainable, they are not quite as high as other sporting events such as road cycling, rowing or running where lower body is dominant.Elite kayakers demonstrate superior aerobic and anaerobic quantities and have reported maximal oxygen consumptions of around 58 ml·kg(-1)·min(-1) (4.7 L·min(-1)) and lactate values of around 12 mM during laboratory and on water testing.
RESUMO
Type 1 diabetes is an autoimmune condition characterised by pancreatic beta cell destruction and absolute insulin deficiency. The strongest predictor of diabetes complications is glycaemic control and achieving HbA1c ≤ 7.0% is the primary management target. However, standard treatment appears to be lacking and adjunctive strategies require consideration. A systematic review was conducted to examine the effect of low-carbohydrate diets on type 1 diabetes management. Four databases were searched from inception until 28 March 2017: MEDLINE; CINAHL; Cochrane Library; and EMBASE. All primary studies containing a methods section (excluding cross-sectional) were included. Reports had to quantitatively measure the effect(s) of a dietary intervention or observed intake over at least two weeks where carbohydrate is below 45% total energy in adults and/or children with type 1 diabetes. The primary outcome was HbA1c and secondary outcomes were severe hypoglycaemia, total daily insulin, BMI, quality of life and mean daily glucose. Seventy-nine full-text articles were assessed for eligibility and nine were included (two randomised controlled trials, four pre-post interventions, two case-series, one case-report). Eight studies reported a mean change in HbA1c with a low-carbohydrate diet. Of these, four reported a non-significant change (P ≥ 0.05) and three reported statistically significant reductions (P < 0.05). Two studies reported severe hypoglycaemia, five reported total insulin, three reported BMI, and one reported blood glucose. Due to the significant heterogeneity of included studies, an overall effect could not be determined. This review presents all available evidence on low-carbohydrate diets for type 1 diabetes and suggests an urgent need for more primary studies.
Assuntos
Diabetes Mellitus Tipo 1/dietoterapia , Dieta com Restrição de Carboidratos , Diabetes Mellitus Tipo 1/metabolismo , Hemoglobinas Glicadas/metabolismo , Humanos , Insulina/metabolismoRESUMO
The artificial sweetener saccharin is available in several forms, including pure saccharin (S) and saccharin sodium salt hydrate (SSSH). Acceptance and preference relative to 2% sucrose for these two forms was assessed using both older female and young male rats. At the higher of two concentrations, â¼0.4%, SSSH was more acceptable and more greatly preferred over 2% sucrose than was a similar concentration of S, whereas little difference between the two forms was detected at the lower concentration, â¼0.1%. These results indicate the importance for researchers of care in choosing and reporting the form of saccharin they use.
Assuntos
Preferências Alimentares , Sacarina , Sódio , Animais , Feminino , Masculino , Ratos , Sacarose , Edulcorantes , PaladarRESUMO
High consumption of sugar-sweetened beverages (SSBs) is a risk factor for weight gain and metabolic disease. Whether this risk is reduced by switching to 'diet' beverages containing low-calorie sweeteners (LCS) is controversial. Two experiments modeled whether a switch from SSB to LCS beverages produced positive outcomes on behavioral and metabolic measures. Both experiments consisted of a Stage 1, in which adult female rats received unrestricted access to 10% sucrose solution in addition to chow and water for 4 (Experiment 1) or 8â¯weeks (Experiment 2). In Stage 2 rats were switched to either saccharin (Suc-Sacch) or water (Suc-Water) or remained on 10% sucrose (Suc-Suc) for a further 4 (Experiment 1) or 7â¯weeks (Experiment 2). Experiment 2 contained a fourth group that was maintained on water throughout (Water-Water). In both experiments energy intake and weight gain in Stage 2 was reduced for Suc-Sacch and Suc-Water groups relative to the Suc-Suc groups and at cull the Suc-Suc groups showed poorer insulin sensitivity and greater g/kg fat than Suc-Water and Suc-Sacch groups. In Experiment 2 short-term place recognition memory was impaired at the end of Stage 1 but recovered to a similar extent in the Suc-Water and Suc-Sacch groups; when the latter groups were compared with the Water-Water group, recovery was found to be essentially complete. A higher saccharin concentration in Experiment 2 than in Experiment 1 increased absolute amounts of saccharin ingested but intake solution volumes remained low. These results show that switching from sucrose to either water or saccharin produces equivalent improvements on both metabolic and cognitive measures.
Assuntos
Tecido Adiposo/metabolismo , Hiperfagia/etiologia , Resistência à Insulina/fisiologia , Reconhecimento Psicológico/fisiologia , Sacarina/efeitos adversos , Água/efeitos adversos , Análise de Variância , Animais , Peso Corporal/fisiologia , Ingestão de Alimentos/fisiologia , Jejum/fisiologia , Feminino , Hiperfagia/prevenção & controle , Ratos , Ratos Sprague-Dawley , Triglicerídeos/sangueRESUMO
Women of reproductive age are at increased risk for iron deficiency (ID) and iron deficiency anemia (IDA), with both implicated in decreased cognitive function (CF). Obesity may complicate this association via inflammatory-mediated ferritin elevation. This cross-sectional study examined the association between hematological iron status (iron replete (IR), ID or IDA) and CF in healthy, young (18-35 years) women of normal-weight (NW: BMI 18.5-24.9 kg/m²) or obese-weight (OB: BMI >30 kg/m²). Participants completed a validated, computer-based cognition assessment evaluating impulsivity, attention, information processing, memory and executive function; CF reported as z-scores (mean ± SD). Iron status and CF were compared between groups via ANOVA, with adjustment for potential confounders (BMI, physical activity, C-reactive protein) via ANCOVA. A total of 157 NW and 142 OB women (25.8 ± 5.1 years) participated. Prevalence of ID and IDA were 14% and 6% respectively, with no significant difference between NW and OB groups. Women with IDA scored significantly lower on attention (although within normal range; ±1 z-score), compared to ID (IDA: -0.75 ± 1.89; ID: 0.53 ± 1.37; p = 0.004) but not IR (0.03 ± 1.33, p = 0.21) groups; there were no significant differences between ID and IR groups (p = 0.34). Adjustment for confounders did not significantly alter these results. In conclusion, women with IDA showed significantly reduced attention compared to women with ID.