Eduardo da Silva Alves

Inflammation and adipose tissue: effects of progressive load training in rats.

IntroductionCytokines (IL-6, IL-10 and TNF-α) are increased after exhaustive exercise in the rat retroperitoneal (RPAT) and mesenteric adipose tissue (MEAT) pads. On the other hand, these cytokines show decreased expression in these depots in response to a chronic exercise protocol. However, the effect of exercise with overload combined with a short recovery period on pro- and anti-inflammatory cytokine expression is unknown. In the present study, we investigated the regulation of cytokine production in the adipose tissue of rats after an overtraining-inducing exercise protocol.MethodsMale Wistar rats were divided into four groups: Control (C), Trained (Tr), Overtrained (OT) and recovered overtrained (R). Cytokines (IL-6, TNF-α and IL-10) levels and Toll Like Receptor 4 (TLR4), Nuclear Factor kBp65 (NF-kBp65), Hormone Sensitive Lipase (HSL) and, Perilipin protein expression were assessed in the adipose tissue. Furthermore, we analysed plasma lipid profile, insulin, testosterone, corticosterone and endotoxin levels, and liver triacylglycerol, cytokine content, as well as apolipoprotein B (apoB) and TLR4 expression in the liver.ResultsOT and R groups exhibited reduced performance accompanied by lower testosterone and increased corticosterone and endotoxin levels when compared with the control and trained groups. IL-6 and IL-10 protein levels were increased in the adipose tissue of the group allowed to recover, in comparison with all the other studied groups. TLR-4 and NF-kBp65 were increased in this same group when compared with both control and trained groups. The protein expression of HSL was increased and that of Perilipin, decreased in the adipose in R in relation to the control. In addition, we found increased liver and serum TAG, along with reduced apoB protein expression and IL-6 and IL-10 levels in the of R in relation to the control and trained groups.ConclusionIn conclusion, we have shown that increases in pro-inflammatory cytokines in the adipose tissue after an overtraining protocol may be mediated via TLR-4 and NF-kBp65 signalling, leading to an inflammatory state in this tissue.

Does physical exercise reduce excessive daytime sleepiness by improving inflammatory profiles in obstructive sleep apnea patients

IntroductionObstructive sleep apnea syndrome (OSAS) is associated with a variety of long-term consequences such as high rates of morbidity and mortality, due to excessive diurnal somnolence as well as cardiovascular and metabolic diseases. Obesity, recurrent episodes of upper airway obstruction, progressive hypoxemia, and sleep fragmentation during sleep cause neural, cardiovascular, and metabolic changes. These changes include activation of peripheral sympathetic nervous system and the hypothalamic–pituitary–adrenal axis, insulin sensitivity, and inflammatory cytokines alterations, which predispose an individual to vascular damage.DiscussionPrevious studies proposed that OSAS modulated the expression and secretion of inflammatory cytokines from fat and other tissues. Independent of obesity, patients with OSAS exhibited elevated levels of C-reactive protein, tumor necrosis factor-α and interleukin-6, which are associated with sleepiness, fatigue, and the development of a variety of metabolic and cardiovascular diseases. OSAS and obesity are strongly associated with each other and share many common pathways that induce chronic inflammation. Previous studies suggested that the protective effect of exercise may be partially attributed to the anti-inflammatory effect of regular exercise, and this effect was observed in obese patients. Although some studies assessed the effects of physical exercise on objective and subjective sleep parameters, the quality of life, and mood in patients with OSAS, no study has evaluated the effects of this treatment on inflammatory profiles. In this review, we cited some studies that directed our opinion to believe that since OSAS causes increased inflammation and has excessive daytime sleepiness as a symptom and being that physical exercise improves inflammatory profiles and possibly OSAS symptoms, it must be that physical exercise improves excessive daytime sleepiness due to its improvement in inflammatory profiles.

Low-Grade Inflammation and Spinal Cord Injury: Exercise as Therapy?

An increase in the prevalence of obesity in people with spinal cord injury can contribute to low-grade chronic inflammation and increase the risk of infection in this population. A decrease in sympathetic activity contributes to immunosuppression due to the lower activation of immune cells in the blood. The effects of physical exercise on inflammatory parameters in individuals with spinal cord injury have not been well described. We conducted a review of the literature published from 1974 to 2012. This review explored the relationships between low-grade inflammation, spinal cord injury, and exercise to discuss a novel mechanism that might explain the beneficial effects of exercise involving an increase in catecholamines and cytokines in people with spinal cord injury.

Comparison of the effects of continuous positive airway pressure, oral appliance and exercise training in obstructive sleep apnea syndrome

OBJECTIVE: There are several treatments for obstructive sleep apnea syndrome, such as weight loss, use of an oral appliance and continuous positive airway pressure, that can be used to reduce the signs and symptoms of obstructive sleep apnea syndrome. Few studies have evaluated the effectiveness of a physical training program compared with other treatments. The aim of this study was to assess the effects of physical exercise on subjective and objective sleep parameters, quality of life and mood in obstructive sleep apnea patients and to compare these effects with the effects of continuous positive airway pressure and oral appliance treatments. METHODS: Male patients with moderate to severe obstructive sleep apnea and body mass indices less than 30 kg/m2 were randomly assigned to three groups: continuous positive airway pressure (n = 9), oral appliance (n = 9) and physical exercise (n = 7). Polysomnographic recordings, blood samples and daytime sleepiness measurements were obtained prior to and after two months of physical exercise or treatment with continuous positive airway pressure or an oral appliance. Clinicaltrials.gov: NCT01289392 RESULTS: After treatment with continuous positive airway pressure or an oral appliance, the patients presented with a significant reduction in the apnea-hypopnea index. We did not observe changes in the sleep parameters studied in the physical exercise group. However, this group presented reductions in the following parameters: T leukocytes, very-low-density lipoprotein and triglycerides. Two months of exercise training also had a positive impact on subjective daytime sleepiness. CONCLUSIONS: Our results suggest that isolated physical exercise training was able to modify only subjective daytime sleepiness and some blood measures. Continuous positive airway pressure and oral appliances modified the apnea-hypopnea index.

Obesity, diabetes and OSAS induce of sleep disorders: exercise as therapy.

Sleep is an integral part of good health. Sleep disorders and variations in sleep habits are associated with a low-grade inflammatory status, which may be either a cause or consequence of other conditions, including obesity, diabetes and cardiovascular disease. Several strategies are available to counteract these conditions including continuous positive airway pressure (CPAP), pharmacological and nutritional interventions, and even surgery. At present, our group is investigating the effect of chronic endurance exercise on sleep alterations.

Angiotensin II-induced JNK activation is mediated by NAD(P)H oxidase in isolated rat pancreatic islets.

Angiotensin II (AII), the active component of the renin angiotensin system (RAS), plays a vital role in the regulation of physiological processes of the cardiovascular system, but also has autocrine and paracrine actions in various tissues and organs. Many studies have shown the existence of RAS in the pancreas of humans and rodents. The aim of this study was to evaluate potential signaling pathways mediated by AII in isolated pancreatic islets of rats. Phosphorylation of MAPKs (ERK1/2, JNK and p38MAPK), and the interaction between proteins JAK/STAT were evaluated. AII increased JAK2/STAT1 (42%) and JAK2/STAT3 (100%) interaction without altering the total content of JAK2. Analyzing the activation of MAPKs (ERK1/2, JNK and p38MAPK) in isolated pancreatic islets from rats we observed that AII rapidly (3 min) promoted a significant increase in the phosphorylation degree of these proteins after incubation with the hormone. Curiously JNK protein phosphorylation was inhibited by DPI, suggesting the involvement of NAD(P)H oxidase in the activation of protein.

Motivational and evolutionary aspects of a physical exercise training program: a longitudinal study.

Several studies have indicated that motivational level and prior expectations influence one’s commitment to physical activity. Moreover, these aspects are not properly described in terms of proximal (SDT, Self Determination Theory) and distal (evolutionary) explanations in the literature. This paper aims to verify if level of motivation (BREQ-2, Behavioral Regulation in Exercise Questionnaire-2) and expectations regarding regular physical exercise (IMPRAF-54) before starting a 1-year exercise program could determine likelihood of completion. Ninety-four volunteers (53 women) included a completed protocol group (CPG; n = 21) and drop-out group (n = 73). The IMPRAF-54 scale was used to assess six different expectations associated with physical activity, and the BREQ-2 inventory was used to assess the level of motivation in five steps (from amotivation to intrinsic motivation). Both questionnaires were assessed before starting a regular exercise program. The CPG group presented higher sociability and lower pleasure scores according to IMPRAF-54 domains. A logistic regression analysis showed that a one-point increment on sociability score increased the chance of completing the program by 10%, and the same one-point increment on pleasure score reduced the chance of completing the protocol by 16%. ROC curves were also calculated to establish IMPRAF-54 cutoffs for adherence (Sociability – 18.5 points – 81% sensibility/50% specificity) and dropout (Pleasure – 25.5 points – 86% sensibility/20% specificity) of the exercise protocol. Our results indicate that an expectation of social interaction was a positive factor in predicting adherence to exercise. Grounded in SDT and its innate needs (competence, autonomy, relatedness), physical exercise is not an end; it is a means to achieve autonomy and self-cohesion. The association of physical activity with social practices, as occurs in hunter-gathering groups, can engage people to be physically active and can provide better results in adherence exercise programs for the general population.

L-Arginine supplementation improves insulin sensitivity and beta cell function in the offspring of diabetic rats through AKT and PDX-1 activation

Maternal hyperglycemia can result in defects in glucose metabolism and pancreatic β-cell function in offspring. The purpose of this study was to evaluate the impact of maternal diabetes mellitus on pancreatic islets, muscle and adipose tissue of the offspring, with or without oral l-Arginine supplementation. The induction of diabetes was performed using streptozotocin (60mg/kg). Animals were studied at 3 months of age and treatment (sucrose or l-Arginine) was administered from weaning. We observed that l-Arg improved insulin sensitivity in the offspring of diabetic mothers (DA), reflected by higher insulin-induced phosphorylation of Akt in muscle and adipose tissue. Insulin resistance is associated with increased oxidative stress and the NADPH oxidase enzyme plays an important role. Our results showed that the augmented interaction of p47PHOX with gp91PHOX subunits of the enzyme in skeletal muscle tissue in the offspring of diabetic rats (DV) was abolished after l-Arg treatment in DA rats. Maternal diabetes caused alterations in the islet functionality of the offspring leading to increased insulin secretion at both low (2.8mM) and high (16.7mM) concentrations of glucose. l-Arg reverses this effect, suggesting that it may be an important modulator in the insulin secretory process. In addition it is possible that l-Arg exerts its effects directly onto essential molecules for the maintenance and survival of pancreatic islets, decreasing protein expression of p47PHOX while increasing Akt phosphorylation and PDX-1 expression. The mechanism by which l-Arg exerts its beneficial effects may involve nitric oxide bioavailability since treatment restored NO levels in the pancreas.

Chronic Exercise Promotes Alterations in the Neuroendocrine Profile of Elderly People

Aging and physical inactivity are 2 factors that favour the development of cardiovascular disease, metabolic syndrome, obesity, and diabetes. In contrast, adopting a habitual moderate exercise routine may be a nonpharmacological treatment alternative for neuroendocrine aging disorders. We aimed to assess the effects of moderate exercise training on the metabolic profiles of elderly people with sedentary lifestyles. Fourteen sedentary, healthy, elderly male volunteers participated in a moderate training regimen for 60 min/day, 3 days/week for 24 weeks at a work rate equivalent to their ventilatory aerobic threshold. The environment was maintained at a temperature of 23±2°C, with a humidity of 60±5%. Blood samples for analysis were collected at 3 intervals: at baseline (1 week before training began), and 3 and 6 months after training. The training promoted increased aerobic capacity (relative VO(2), and time and velocity to VO(2)max; (p<0.05)) and reduced serum α-MSH (p<0.05) after 3 months of training when compared with the baseline data. In addition, serum thyroid hormone (T3 and T4) was reduced after 6 months of training compared with baseline levels. Our results demonstrate that a moderate exercise training protocol improves the metabolic profile of older people, and metabolic adaptation is dependent on time.

Assessment of Body Composition and Sport Performance of Brazilian Paralympic Swim Team Athletes

CONTEXT Body-composition assessments of high-performance athletes are very important for identifying physical performance potential. Although the relationship between the kinanthropometric characteristics and performance abilities of Olympic swimmers is extremely important, this subject is not completely understood for Paralympic swimmers. OBJECTIVE To investigate the relationship between body composition and sport performance in Brazilian Paralympic swimmers 6 mo after training. DESIGN Experimental pre/posttest design. SETTING Research laboratory and field evaluations of swimming were conducted to verify the 50-m freestyle time of each athlete. PARTICIPANTS 17 Brazilian Paralympic swim team athletes (12 men, 5 women). MAIN OUTCOME MEASURES Body-composition assessments were performed using a BOD POD, and swimming performance was assessed using the 50-m freestyle, which was performed twice: before and after 6 mo of training. RESULTS Increased lean mass and significantly reduced relative fat mass and swimming time (P < .05) were observed 6 mo after training. Furthermore, a positive correlation between body-fat percentage and performance (r = .66, P < .05) was observed, but there was no significant correlation between body density and performance (r = -.14, P > .05). CONCLUSIONS After a 6-mo training period, Paralympic swimmers presented reduced fat mass and increased lean body mass associated with performance, as measured by 50-m freestyle time. These data suggest that reduced fat-mass percentage was significantly correlated with improved swimming performance in Paralympic athletes.