Avaliação da musculatura inspiratória e expiratória na doença pulmonar obstrutiva crônica leve e grave comparada aos indivíduos saudáveis

Introdução: A DPOC é uma doença respiratória prevenível e tratável, caracterizada por limitação persistente ao fluxo aéreo, hiperinsuflação e aprisionamento aéreo. A dispneia e a intolerância aos esforços, decorrentes destas alterações fisiopatológicas sofre influência de vários fatores. Dentre estes, o recrutamento e a sobrecarga imposta aos músculos inspiratórios e expiratórios são de fundamental importância, porém a participação destes ainda não foi completamente elucidada em diferentes gravidades da doença. Objetivos: O objetivo principal deste estudo foi avaliar a mecânica ventilatória, e o grau de recrutamento da musculatura inspiratória e expiratória na DPOC leve e grave, na condição de repouso e durante um teste máximo de exercício, comparado a um grupo de indivíduos saudáveis. Metodologia: Trata-se de um estudo transversal envolvendo 36 indivíduos, sendo 24 pacientes portadores de DPOC e 12 voluntários sadios. As avaliações foram divididas em 2 visitas. No D1, foram realizadas uma avaliação clínica, avaliação de dispneia (mMRC) e de qualidade de vida (SGRQ), além da prova de função pulmonar completa. Na 2ª visita, realizada com intervalo de 1 semana, foram avaliadas: as pressões respiratórias máximas estáticas por meio de métodos volitivos (PImax, PEmax, SNIP, Pes sniff, Pga sniff e Pdi sniff) e não volitivos (Twitch cervical bilateral e T10); avaliação da sincronia toracoabdominal por pletismografia de indutância; avaliação do recrutamento dos músculos inspiratórios e expiratórios ao repouso pela eletromiografia de superfície; e, posteriormente, um teste de exercício cardiopulmonar incremental para estudo de todas essas variáveis no esforço. Resultados: Foram avaliados 24 pacientes (12 leves e 12 graves) e 12 indivíduos saudáveis da mesma faixa etária. A maioria dos pacientes apresentava comprometimento significativo da qualidade de vida e os pacientes do grupo grave eram mais sintomáticos. A função pulmonar encontrava-se alterada na maioria dos pacientes. Destes, 79,2% apresentavam aprisionamento aéreo e 70,8% tinham redução da DLCO. Tais alterações foram semelhantes nos 2 grupos de pacientes. A força muscular estática medida por métodos volitivos e não volitivos estava reduzida nos 2 grupos e mostrou relação com o VEF1. No exercício, a dispneia foi o principal motivo para interrupção do teste em 70% dos pacientes. A HD esteve presente em 87,5% dos pacientes. O comportamento das pressões respiratórias foi significativamente diferente entre os 3 grupos. Os pacientes com DPOC apresentaram maior atividade diafragmática (Pdi) comparado aos controles e a participação da musculatura expiratória também foi maior neste grupo, principalmente nos graves. Apesar disso, os pacientes com DPOC apresentaram uma eficiência mecânica reduzida, ou seja, esse incremento da força muscular foi insuficiente para manter uma ventilação adequada para uma determinada carga. Com o aumento da demanda ventilatória, houve recrutamento precoce e progressivo dos músculos inspiratórios e expiratórios durante o exercício. O trabalho resistivo e o expiratório foram significativamente diferentes entre os controles e os pacientes com DPOC desde o início do exercício. Como consequência destas alterações, a intensidade da dispneia durante o TECP foi maior nos pacientes com DPOC (leve e grave) para a mesma carga e mesma ventilação-minuto (VE), quando comparada aos indivíduos do grupo-controle. Conclusões: O conjunto destes achados demonstra que o comprometimento dos músculos inspiratórios e expiratórios contribuiu significativamente para a dispneia e a intolerância ao exercício tanto no DPOC leve quanto no DPOC grave. E que este comprometimento pode não ser detectado com os testes máximos de força ao repouso

Multiple component patient safety intervention in English hospitals:controlled evaluation of second phase

Objective: To independently evaluate the impact of the second phase of the Health Foundation's Safer Patients Initiative (SPI2) on a range of patient safety measures. Design: A controlled before and after design. Five substudies: survey of staff attitudes; review of case notes from high risk (respiratory) patients in medical wards; review of case notes from surgical patients; indirect evaluation of hand hygiene by measuring hospital use of handwashing materials; measurement of outcomes (adverse events, mortality among high risk patients admitted to medical wards, patients' satisfaction, mortality in intensive care, rates of hospital acquired infection). Setting: NHS hospitals in England. Participants: Nine hospitals participating in SPI2 and nine matched control hospitals. Intervention The SPI2 intervention was similar to the SPI1, with somewhat modified goals, a slightly longer intervention period, and a smaller budget per hospital. Results: One of the scores (organisational climate) showed a significant (P=0.009) difference in rate of change over time, which favoured the control hospitals, though the difference was only 0.07 points on a five point scale. Results of the explicit case note reviews of high risk medical patients showed that certain practices improved over time in both control and SPI2 hospitals (and none deteriorated), but there were no significant differences between control and SPI2 hospitals. Monitoring of vital signs improved across control and SPI2 sites. This temporal effect was significant for monitoring the respiratory rate at both the six hour (adjusted odds ratio 2.1, 99% confidence interval 1.0 to 4.3; P=0.010) and 12 hour (2.4, 1.1 to 5.0; P=0.002) periods after admission. There was no significant effect of SPI for any of the measures of vital signs. Use of a recommended system for scoring the severity of pneumonia improved from 1.9% (1/52) to 21.4% (12/56) of control and from 2.0% (1/50) to 41.7% (25/60) of SPI2 patients. This temporal change was significant (7.3, 1.4 to 37.7; P=0.002), but the difference in difference was not significant (2.1, 0.4 to 11.1; P=0.236). There were no notable or significant changes in the pattern of prescribing errors, either over time or between control and SPI2 hospitals. Two items of medical history taking (exercise tolerance and occupation) showed significant improvement over time, across both control and SPI2 hospitals, but no additional SPI2 effect. The holistic review showed no significant changes in error rates either over time or between control and SPI2 hospitals. The explicit case note review of perioperative care showed that adherence rates for two of the four perioperative standards targeted by SPI2 were already good at baseline, exceeding 94% for antibiotic prophylaxis and 98% for deep vein thrombosis prophylaxis. Intraoperative monitoring of temperature improved over time in both groups, but this was not significant (1.8, 0.4 to 7.6; P=0.279), and there were no additional effects of SPI2. A dramatic rise in consumption of soap and alcohol hand rub was similar in control and SPI2 hospitals (P=0.760 and P=0.889, respectively), as was the corresponding decrease in rates of Clostridium difficile and meticillin resistant Staphylococcus aureus infection (P=0.652 and P=0.693, respectively). Mortality rates of medical patients included in the case note reviews in control hospitals increased from 17.3% (42/243) to 21.4% (24/112), while in SPI2 hospitals they fell from 10.3% (24/233) to 6.1% (7/114) (P=0.043). Fewer than 8% of deaths were classed as avoidable; changes in proportions could not explain the divergence of overall death rates between control and SPI2 hospitals. There was no significant difference in the rate of change in mortality in intensive care. Patients' satisfaction improved in both control and SPI2 hospitals on all dimensions, but again there were no significant changes between the two groups of hospitals. Conclusions: Many aspects of care are already good or improving across the NHS in England, suggesting considerable improvements in quality across the board. These improvements are probably due to contemporaneous policy activities relating to patient safety, including those with features similar to the SPI, and the emergence of professional consensus on some clinical processes. This phenomenon might have attenuated the incremental effect of the SPI, making it difficult to detect. Alternatively, the full impact of the SPI might be observable only in the longer term. The conclusion of this study could have been different if concurrent controls had not been used.

Intolérence à l'effort en hypertension artérielle pulmonaire : Implication des déterminants périphériques

L’hypertension artérielle pulmonaire (HTAP) est une maladie caractérisée par l’augmentation progressive des résistances vasculaires pulmonaires causant une augmentation de la pression artérielle pulmonaire qui mène au décès prématuré des patients. Malgré une amélioration rapide ces dernières années des traitements spécifiques, les patients souffrant d’HTAP demeurent dyspnéiques et intolérants à l’effort. L’atteinte vasculaire pulmonaire est actuellement irréversible. Elle est également la source de plusieurs anomalies au niveau des systèmes cardiovasculaires, ventilatoires et musculaires constituant les principaux déterminants physiologiques de la capacité à l’effort des patients. Cette thèse a investigué différentes facettes de la tolérance à l’effort en HTAP : les différents mécanismes ayant un impact sur l’apport musculaire en oxygène, l’altération des voies de signalisation cellulaire impliquées dans l’angiogenèse musculaire et les mécanismes ayant un impact sur la régulation du débit sanguin et l’oxygénation cérébrale en HTAP. Nous avons premièrement documenté une diminution de l’apport en oxygène aux muscles squelettiques à l’effort des patients en relation avec une diminution de la densité capillaire musculaire. Ce défaut d’angiogenèse corrélait d’ailleurs avec la capacité à l’effort des sujets. Par la suite, nous avons étudié les voies de signalisations cellulaires de l’angiogenèse musculaire. Ces résultats ont permis de démontrer une diminution de l’expression de miR-126, unique aux patients HTAP, qui était responsable de la diminution de la densité capillaire et qui contribuait à leur intolérance à l’effort. De plus, il était possible de moduler in vivo l’expression de miR-126. L’expérimentation in vivo, à l’aide d’un modèle murin d’HTAP, a permis de rétablir l’expression de miR-126, d’augmenter la microcirculation musculaire et d’améliorer la tolérance à l’effort des animaux, ce qui met en lumière le potentiel thérapeutique de l’angiogenèse musculaire pour améliorer la capacité à l’effort en HTAP. Notre dernier projet a démontré que les patients HTAP présentaient une diminution de débit sanguin cérébral. Ce projet a également démontré que les changements de pression artérielle sont moins bien amortis par les vaisseaux cérébraux des patients et que leurs vaisseaux cérébraux étaient moins réactifs aux changements de CO2. Les patients présentaient aussi une augmentation de la sensibilité des chémorécepteurs centraux qui contribuait à augmenter leur ventilation au repos, mais aussi à l’exercice. Finalement, à l’effort, nous avons démontré que le débit sanguin cérébral des patients HTAP était principalement influencé par la pression artérielle alors que chez les sujets sains, le débit sanguin cérébral était influencé principalement par la PETCO2. Nous avons également démontré que les patients HTAP présentaient une diminution progressive de leur oxygénation cérébrale, qui corrélait avec leur capacité à l’effort. Les résultats obtenus au cours de ce doctorat démontrent bien que la capacité à l’effort en HTAP est aussi déterminée par plusieurs anomalies physiopathologiques périphériques.

Association between physical activity and cardiorespiratory factors in adolescents: a cross-sectional exploratory study

Background: Currently, under half of the adolescents reach recommended daily levels of physical activity (PA). It is known that higher levels of PA lead to higher levels of cardiorespiratory fitness (CRF) and therefore, a health-related CRF criterion value could contribute to identify the target population for primary cardiovascular disease prevention. Therefore, the aim of this study was to explore the relation between PA levels and CRF factors in healthy adolescents. Methods: A cross-sectional exploratory study with healthy adolescents aged 12-18 years old was conducted. Socio-demographic and body composition data were collected using a questionnaire. PA level was scored with the Physical Activity Index (PAI) and CRF assessment included lung function (LF) measured with spirometry and exercise tolerance measured with Incremental Shuttle Walking Test (ISWT). According to PAI scores the sample was divided in two groups: 1 (sedentary, low and moderately active); 2 (vigorously active (VA)). Descriptive statistics were applied to characterise the sample. Independent sample t-tests assessed differences between groups and simple logistic regressions identified the predictors of being VA. Results: The study included 115 adolescents (14.63±1.70 years old; 56.52% female). Adolescents presented a normal body mass index=21.19±3.14 Kg.m-2) and LF (forced expiratory volume in the first second (FEV1)=105.58±12.73% of the predicted). Significant differences were found between groups in height (G1–163.44±8.01; G2–167±8.65; p=0.024), LF (FEV1/ forced vital capacity (FVC); G1–97.58±10.66; G2–94.04±8.04; p=0.049), ISWT distance (G1– 1089.81±214.04; G2–1173.60±191.86; p=0.038); heart rate (HR) at rest (G1– 84.61±13.68; G2–79.23±13.81; p=0.038), HR at the end of the best ISWT (G1– 124.71±37.57; G2–133.54±33.61; p=0.041) and percentage of the maximal HR achieved during ISWT (G1–63.09±19.03; G2–67.53±17.08; p=0.043). Simple logistic regressions showed that height (OR–1.054; 95%CI 1.006-1.104), ISWT distance (OR–1.002; 95%CI 1.000-1.004) and HR at rest (OR–0.971; 95%CI 0.945-0.999) were predictors of being VA. Conclusions: Results suggest that more physically active adolescents have a better CRF profile. The findings suggest that PA is important to adolescents’ health status and it should be encouraged since childhood. Clinical practice will benefit from the use of PAI, ISWT and HR findings, allowing physiotherapists to use it for prescribing exercise.

Efeitos do exercício moderado prévio com oclusão vascular sobre a cinética da oferta e utilização do oxigênio em um exercício subsequente de alta intensidade

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Educação Física, Programa de Pós-Graduação Stricto-Sensu em Educação Física, 2015.

Glucose Tolerance and Insulin Action in Monosodium Glutamate (MSG) Obese Exercise-trained Rats

The present study was designed to evaluate the effects of chronic aerobic exercise (swimming, 1h/day, 5 days/week, with an overload of 5% body weight) on glucose metabolism in obese male Wistar rats. Hypothalamic obesity was induced through administration of monosodium glutamate (MSG) at 4 mg/g of body weight every other day from birth to 14 days old. Fourteen weeks after drug administration, the rats were separated into two groups: MSG-S (sedentary) and MSG-T (swimming for 10 weeks). Rats of the same age and strain, receiving saline in place of MSG, were used as control (C), and subdivided into two groups: C-S and C-T. At the end of the experimental period, an oral glucose tolerance test was performed and serum glucose (AG) and insulin (AI) were evaluated. A constant for serum glucose decrease (Kitt) in response to exogenous insulin was calculated. Soleus muscle strips and adipose tissue samples were incubated and insulin stimulated glucose uptake determined. No differences were observed in AG among the 4 groups. MSG-S rats showed higher AI (418%) and lower Kitt (92.3%) than C-S rats. T-rats showed higher glucose uptake by muscle (224.0%) and adipose tissues (94.1%) than S-rats. Among trained rats, glucose uptake by muscle was higher in MSG-T (5.4%) than in C-T. while the opposite was observed in adipose tissue (39% higher in C-T). Chronic aerobic exercise was able to improve glucose tolerance and reduce insulin resistance in MSG-obese rats. These effects were associated to an increase in glucose uptake by muscle and adipose tissue in response to insulin.

The psychobiological model: a new explanation to intensity regulation and (in)tolerance in endurance exercise

The mechanisms underpinning fatigue and exhaustion, and the specific sources of exercise-endurance intensity regulation and (in)tolerance have been investigated for over a century. Although several scientific theories are currently available, over the past five years a new framework called Psychobiological model has been proposed. This model gives greater attention to perceptual and motivational factors than its antecedents, and their respective influence on the conscious process of decision-making and behavioral regulation. In this review we present experimental evidences and summarize the key points of the Psychobiological model to explain intensity regulation and (in)tolerance in endurance exercise. Still, we discuss how the Psychobiological model explains training-induced adaptations related to improvements in performance, experimental manipulations, its predictions, and propose future directions for this investigative area. The Psychobiological model may give a new perspective to the results already published in the literature, helping scientists to better guide their research problems, as well as to analyze and interpret new findings more accurately.

Creatine supplementation spares muscle glycogen during high intensity intermittent exercise in rats

Background: The effects of creatine (CR) supplementation on glycogen content are still debatable. Thus, due to the current lack of clarity, we investigated the effects of CR supplementation on muscle glycogen content after high intensity intermittent exercise in rats. Methods: First, the animals were submitted to a high intensity intermittent maximal swimming exercise protocol to ensure that CR-supplementation was able to delay fatigue ( experiment 1). Then, the CR-mediated glycogen sparing effect was examined using a high intensity intermittent sub-maximal exercise test ( fixed number of bouts; six bouts of 30-second duration interspersed by two-minute rest interval) ( experiment 2). For both experiments, male Wistar rats were given either CR supplementation or placebo (Pl) for 5 days. Results: As expected, CR-supplemented animals were able to exercise for a significant higher number of bouts than Pl. Experiment 2 revealed a higher gastrocnemius glycogen content for the CR vs. the Pl group (33.59%). Additionally, CR animals presented lower blood lactate concentrations throughout the intermittent exercise bouts compared to Pl. No difference was found between groups in soleus glycogen content. Conclusion: The major finding of this study is that CR supplementation was able to spare muscle glycogen during a high intensity intermittent exercise in rats.

Monitoring stress tolerance and occurrences of upper respiratory illness in basketball players by means of psychometric tools and salivary biomarkers

The aim of the study was to evaluate the possible relationships between stress tolerance, training load, banal infections and salivary parameters during 4 weeks of regular training in fifteen basketball players. The Daily Analysis of Life Demands for Athletes` questionnaire (sources and symptoms of stress) and the Wisconsin Upper Respiratory Symptom Survey were used on a weekly basis. Salivary cortisol and salivary immunoglobulin A (SIgA) were collected at the beginning (before) and after the study, and measured by enzyme-linked immunosorbent assay (ELISA). Ratings of perceived exertion (training load) were also obtained. The results from ANOVA with repeated measures showed greater training loads, number of upper respiratory tract infection episodes and negative sensation to both symptoms and sources of stress, at week 2 (p < 0.05). Significant increases in cortisol levels and decreases in SIgA secretion rate were noted (before to after). Negative sensations to symptoms of stress at week 4 were inversely and significantly correlated with SIgA secretion rate. A positive and significant relationship between sources and symptoms of stress at week 4 and cortisol levels were verified. In summary, an approach incorporating in conjunction psychometric tools and salivary biomarkers could be an efficient means of monitoring reaction to stress in sport. Copyright (C) 2010 John Wiley & Sons, Ltd.

Strength training increases walking tolerance in intermittent claudication patients: randomized trial

Objective: To analyse the effects of strength training (ST) in walking capacity in patients with intermittent claudication (IC) compared with walking training (WT) effects. Methods. Thirty patients with IC were randomized into ST and WT. Both groups trained twice a week for 12 weeks at the same rate of perceived exertion. ST consisted of three sets of 10 repetitions of whole body exercises. WT consisted of 15 bouts of 2-minute walking. Before and after the training program walking capacity, peak VO(2), VO(2) at the first stage of treadmill test, ankle brachial index, ischemic window, and knee extension strength were measured. Results: ST improved initial claudication distance (358 +/- 224 vs 504 +/- 276 meters; P < .01), total walking distance (618 +/- 282 to 775 +/- 334 meters; P < .01), VO(2), at the first stage of treadmill test (9.7 +/- 2.6 vs 8.1 +/- 1.7 mL . kg(-1) . minute; P < .01), ischemic window (0.81 +/- 1.16 vs 0.43 +/- 0.47 mm Hg minute meters(-1); P = .04), and knee extension strength (19 +/- 9 vs 21 +/- 8 kg and 21 +/- 9 vs 23 +/- 9; P < .01). Strength increases correlated with the increase in initial claudication distance (r = 0.64; P = .01.) and with the decrease ill VO(2) measured at the first stage of the treadmill test (r = -0.52; P = .04 and r = -0.55; P = .03). Adaptations following ST were similar to the ones observed after WT; however, patients reported lower pain during ST than WT (P < .01). Conclusion: ST improves functional limitation similarly to WT but it produces lower pain, suggesting that this type of exercise could be useful and should be considered in patients with IC. (J Vase Surg 2010;51:89-95.)

Effects of creatine supplementation on glucose tolerance and insulin sensitivity in sedentary healthy males undergoing aerobic training

Recent findings have indicated that creatine supplementation may affect glucose metabolism. This study aimed to examine the effects of creatine supplementation, combined with aerobic training, on glucose tolerance in sedentary healthy male. Subjects (n = 22) were randomly divided in two groups and were allocated to receive treatment with either creatine (CT) (similar to 10g .day over three months) or placebo (PT) (dextrose). Administration of treatments was double blind. Both groups underwent moderate aerobic training. An oral glucose tolerance test (OGTT) was performed and both fasting plasma insulin and the homeostasis model assessment (HOMA) index were assessed at the start, and after four, eight and twelve weeks. CT demonstrated significant decrease in OGTT area under the curve compared to PT (P = 0.034). There were no differences between groups or over time in fasting insulin or HOMA. The results suggest that creatine supplementation, combined with aerobic training, can improve glucose tolerance but does not affect insulin sensitivity, and may warrant further investigation with diabetic subjects.

Dietary chromium tripicolinate supplementation reduces glucose concentrations and improves glucose tolerance in normal-weight cats

The effect of dietary chromium supplementation on glucose and insulin metabolism in healthy, non-obese cats was evaluated. Thirty-two cats were randomly divided into four groups and fed experimental diets consisting of a standard diet with 0 ppb (control), 150 ppb, 300 ppb, or 600 ppb added chromium as chromium tripicolinate. Intravenous glucose tolerance, insulin tolerance and insulin sensitivity tests with minimal model analysis were performed before and after 6 weeks of feeding the test diets. During the glucose tolerance test, glucose concentrations, area under the glucose concentration-time curve, and glucose half-life (300 ppb only), were significantly lower after the trial in cats supplemented with 300 ppb and 600 ppb chromium, compared with values before the trial. Fasting glucose concentrations measured on a different day in the biochemistry profile were also significantly lower after supplementation with 600 ppb chromium. There were no significant differences in insulin concentrations or indices in either the glucose or insulin tolerance tests following chromium supplementation, nor were there any differences between groups before or after the dietary trial. Importantly, this study has shown a small but significant, dose-dependent improvement in glucose tolerance in healthy, non-obese cats supplemented with dietary chromium. Further long-term studies are warranted to determine if the addition of chromium to feline diets is advantageous. Cats most likely to benefit are those with glucose intolerance and insulin resistance from lack of exercise, obesity and old age. Healthy cats at risk of glucose intolerance and diabetes from underlying low insulin sensitivity or genetic factors may also benefit from long-term chromium supplementation. (C) 2002 ESFM and AAFP.

Reported Use of Anabolic Steroids and Ergogenic Substances in Gym/Health Club Settings: Associations with Psychosocial and Exercise Behavior Factors

The industry of ergogenic supplements is increasing rapidly (Cole et al., 2003). Supplements may constitute an important aid for some vigourous exercise routines, but they may also be used as a hypothetical mean to achieve increases in muscular mass. This supposed effect of suplements can lead to its use by individuals who have high levels of drive for muscularity, a condition that is known to be associated with muscular dismorphy (or as it has been called recently vigorexia, Pope et al., 1997). Another psychological factor which can influence supplement consumption is exercise dependence, a borderline problem, as most studies present a prevalence of less than 10% in regular exercisers (Palmeira & Matos, 2006). Symptoms like tolerance or continuity could lead to the use of ergogenic aids to maintain the exercise levels. Also of interest for the understanding of the use of suplements are exercise frequency, volume and intensity, which could explain the ratesof consumption on a more physicological level.