Thiago Santos Rosa

Treatment of obese adolescents: the influence of periodization models and ACE genotype.

The aims of the present study were to compare the effects of two periodization models on metabolic syndrome risk factors in obese adolescents and verify whether the angiotensin‐converting enzyme (ACE) genotype is important in establishing these effects. A total of 32 postpuberty obese adolescents were submitted to aerobic training (AT) and resistance training (RT) for 14 weeks. The subjects were divided into linear periodization (LP, n = 16) or daily undulating periodization (DUP, n = 16). Body composition, visceral and subcutaneous fat, glycemia, insulinemia, homeostasis model assessment of insulin resistance (HOMA‐IR), lipid profiles, blood pressure, maximal oxygen consumption (VO2max), resting metabolic rate (RMR), muscular endurance were analyzed at baseline and after intervention. Both groups demonstrated a significant reduction in body mass, BMI, body fat, visceral and subcutaneous fat, total and low‐density lipoprotein cholesterol, blood pressure and an increase in fat‐free mass, VO2max, and muscular endurance. However, only DUP promoted a reduction in insulin concentrations and HOMA‐IR. It is important to emphasize that there was no statics difference between LP and DUP groups; however, it appears that there may be bigger changes in the DUP than LP group in some of the metabolic syndrome risk factors in obese adolescents with regard to the effect size (ES). Both periodization models presented a large effect on muscular endurance. Despite the limitation of sample size, our results suggested that the ACE genotype may influence the functional and metabolic characteristics of obese adolescents and may be considered in the future strategies for massive obesity control.

Chronic conventional resistance exercise reduces blood pressure in stage 1 hypertensive men.

Abstract Moraes, MR, Bacurau, RFP, Casarini, DE, Jara, ZP, Ronchi, FA, Almeida, SS, Higa, EMS, Pudo, MA, Rosa, TS, Haro, AS, Barros, CC, Pesquero, JB, Würtele, M, and Araujo, RC. Chronic conventional resistance exercise reduces blood pressure in stage 1 hypertensive men. J Strength Cond Res 26(4): 1122–1129, 2012—To investigate the antihypertensive effects of conventional resistance exercise (RE) on the blood pressure (BP) of hypertensive subjects, 15 middle-aged (46 ± 3 years) hypertensive volunteers, deprived of antihypertensive medication (reaching 153 ± 6/93 ± 2 mm Hg systolic/diastolic BP after a 6-week medication washout period) were submitted to a 12-week conventional RE training program (3 sets of 12 repetitions at 60% 1 repetition maximum, 3 times a week on nonconsecutive days). Blood pressure was measured in all phases of the study (washout, training, detraining). Additionally, the plasma levels of several vasodilators or vasoconstrictors that potentially could be involved with the effects of RE on BP were evaluated pre- and posttraining. Conventional RE significantly reduced systolic, diastolic, and mean BP, respectively, by an average of 16 (p < 0.001), 12 (p < 0.01), and 13 mm Hg (p < 0.01) to prehypertensive values. There were no significant changes of vasoactive factors from the kallikrein-kinin or renin-angiotensin systems. After the RE training program, the BP values remained stable during a 4-week detraining period. Taken together, this study shows for the first time that conventional moderate-intensity RE alone is able to reduce the BP of stage 1 hypertensive subjects free of antihypertensive medication. Moreover, the benefits of BP reduction achieved with RE training remained unchanged for up to 4 weeks without exercise.

Plasma Kallikrein and Angiotensin I-converting enzyme N- and C-terminal domain activities are modulated by the insertion/deletion polymorphism

Angiotensin I-converting enzyme (ACE) is recognized as one of the main effector molecules involved in blood pressure regulation. In the last few years some polymorphisms of ACE such as the insertion/deletion (I/D) polymorphism have been described, but their physiologic relevance is poorly understood. In addition, few studies investigated if the specific activity of ACE domain is related to the I/D polymorphism and if it can affect other systems. The aim of this study was to establish a biochemical and functional characterization of the I/D polymorphism and correlate this with the corresponding ACE activity. For this purpose, 119 male brazilian army recruits were genotyped and their ACE plasma activities evaluated from the C- and N-terminal catalytic domains using fluorescence resonance energy transfer (FRET) peptides, specific for the C-domain (Abz-LFK(Dnp)OH), N-domain (Abz-SDK(Dnp)P-OH) and both C- and N-domains (Abz-FRK(Dnp)P-OH). Plasma kallikrein activity was measured using Z-Phe-Arg-AMC as substrate and inhibited by selective plasma kallikrein inhibitor (PKSI). Some physiological parameters previously described related to the I/D polymorphism such as handgrip strength, blood pressure, heart rate and BMI were also evaluated. The genotype distribution was II n=27, ID n=64 and DD n=28. Total plasma ACE activity of both domains in II individuals was significantly lower in comparison to ID and DD. This pattern was also observed for C- and N-domain activities. Difference between ID and DD subjects was observed only with the N-domain specific substrate. Blood pressure, heart rate, handgrip strength and BMI were similar among the genotypes. This polymorphism also affected the plasma kallikrein activity and DD group presents high activity level. Thus, our data demonstrate that the I/D ACE polymorphism affects differently both ACE domains without effects on handgrip strength. Moreover, this polymorphism influences the kallikrein-kinin system of normotensive individuals.

Cardiovascular and Renal Effects of Birdseed Associated with Aerobic Exercise in Rats.

INTRODUCTION Phalaris canariensis L. (Pc), known as birdseed, is rich in tryptophan. The aqueous extract of Pc (AEPc) treatment reduced systolic blood pressure (SBP) in spontaneously hypertensive rats (SHR) via mechanisms mediated by the tryptophan metabolizing enzyme indoleamine 2,3-dioxygenase (IDO). Hypertension is a risk factor to cardiovascular and renal diseases. Considering that physical exercise improves hypertension and cardiovascular function, the aim of this study was to evaluate whether the benefits of exercise (Ex) would be enhanced by concomitant AEPc treatment (400 mg·kg·d p.o.). METHODS Vascular reactivity was assessed in aorta rings from SHR treated with AEPc for 4 wk. Training intensity was based on maximal lactate steady state obtained during the 2-wk adaptation period in a treadmill running. Then exercised (60 min running, five times per week during 8 wk) or sedentary SHR were untreated or treated with AEPc during 8 wk. SBP was estimated by plethysmograph. Heart mass and body mass were used to obtain the index of cardiac hypertrophy. Glucose tolerance test was evaluated by oral glucose overload, and the mRNA expressions of indoleamine 2,3-dioxygenase, interleukin 1β (IL-1β), and IL-10 in the kidney were obtained by real time polymerase chain reaction. RESULTS AEPc induced endothelial-mediated vascular relaxation. AEPc or Ex alone reduced SBP, the index of cardiac hypertrophy and ventricular fibrosis, improved glucose metabolism, and attenuated proteinuria and the renal expression of the proinflammatory IL-1β with an overexpression in the anti-inflammatory IL-10. AEPc potentiated the benefits of the Ex on the cardiovascular system, metabolic parameters, and renal inflammation. CONCLUSION Birdseed reduced cardiovascular risk related to hypertension and had positive effects when associated to physical exercise.

Role of leptin in body temperature regulation and lipid metabolism following splenectomy

OBJECTIVE The physiological changes in serum triglycerides and body temperature that are induced by splenectomy are poorly understood. Therefore, the aim of this study was to investigate parameters related to lipid and glucose metabolism, as well as thermoregulation, in splenectomized mice. DESIGN AND METHODS Splenectomized and sham-operated WT mice (C57Bl/6) and ob/ob mice were randomly divided and treated with a standard or high fat diet, and several metabolic parameters and the body temperature were investigated. RESULTS Splenectomy induced a significant increase in triglyceride levels regardless of the diet. It was found that the splenectomized WT mice showed greater serum leptin and insulin levels compared with the sham-operated mice. Additionally, the body temperatures of the splenectomized WT mice were greater than the body temperatures of the control animals regardless of diet; this result too was observed without any significant change in the temperature of the splenectomized ob/ob animals. CONCLUSION The results suggest that splenectomy interferes with serum triglyceride metabolism and body temperature regardless of the fat content in the diet and that leptin is involved in the regulation of body temperature related to splenectomy.

Resistance training downregulates macrophages infiltration in the kidney of 5/6 nephrectomized rats

Introduction: Chronic kidney disease (CKD) is considered a significant world health problem with elevated mortality rates. Patients with CKD are restricted to mild physical activity, present chronic inflammatory state and loss of muscle strength. Currently, the influence of resistance exercise (RE) on the progression of renal disease has not being fully elucidated. Purpose: To evaluate the effects of RE on the progression of CKD in a remnant kidney model (5/6Nx) in rats. Methods: Eight‐week‐old Wistar rats were submitted to 5/6 nephrectomy and were divided into four groups: Sham sedentary (Sham SD); Sham RE (Sham RE); 5/6Nx SD and 5/6Nx RE. The animals were trained for 8 weeks in a vertical climbing ladder for 3 days per week, on non‐consecutive days. Results: As expected, 5/6Nx SD group presented a markedly loss of renal function, increased plasma inflammatory cytokines and increased oxidative stress with a reduced activity of nitric oxide. The higher macrophage infiltration and fibrosis confirmed these conditions. RE attenuated systolic blood pressure and renal function decrease and also improved serum lipid parameters in 5/6 Nx animals. It was evident the increase of muscle strength and mass in the trained groups while the sedentary group showed reduced muscle weight and strength compared to Sham SD. Conclusions: RE implemented following 5/6Nx retard the progression of chronic kidney injury while simultaneously allowed the maintenance of skeletal muscle strength.

Resistance training attenuates inflammation and the progression of renal fibrosis in chronic renal disease

&NA; Patients with chronic kidney disease (CKD) have progressive renal fibrosis, inflammation, and reduced muscle mass and strength. Resistance training (RT) has been suggested to mitigate the loss of muscle mass, of strength and the inflammation in CKD, but the mechanisms are unknown. The aim of this study was to evaluate the influence of RT on renal fibrosis, renal cytokine expression, creatine kinase levels, and muscle mass and strength in CKD rats. A CKD model was obtained by 5/6 nephrectomy (Nx). Fifteen 8‐week‐old male rats were divided into 3 groups: Sham (control), Nx SED (CKD sedentary) and Nx RT (CKD trained). The RT consisted of ladder climbing at 70% of the animals maximal carrying capacity for 10 weeks. Muscle strength, creatine kinase levels, renal fibrosis and mRNA interleukin (IL)‐4, IL‐6 and IL‐10 were analyzed after the RT protocol. There was significant improvement in the muscle strength and creatine kinase levels in the Nx RT group. Moreover, renal fibrosis and inflammation were attenuated, with increased IL‐4 and IL‐10 expression and reduced IL‐6 expression in the Nx RT group compared with that in the Nx SED group. No difference in muscle mass was observed among the groups. In conclusion, RT was effective in reducing fibrosis and inflammation, in addition to increasing muscle strength and creatine kinase levels, in rats with CKD, independent of muscle mass.

Oxidative stress, inflammatory, psychological markers and severity of respiratory infections are negatively affected during the pre-contest period in amateur bodybuilders

We examined whether off-season (OffS) and pre-contest (PreC) periods affect blood oxidative stress, inflammatory, immunological, and psychological markers in 20 bodybuilders. The athletes recorded their food intake (3-day record), physical activities, mood states (Profile of Mood States, POMS), recovery-stress (Recovery-Stress Questionnaire for Athletes, RESTQ-Sport), and upper respiratory symptoms (Wisconsin Upper Respiratory Symptom Survey, WURSS-21), and blood was obtained for biochemical analysis. Almost all athletes were in positive energy balance during OffS, while bodybuilders presented markedly restricted energy intake (∼45%) leading to loss of weight (-9%) and fat mass (-45%) with preservation of fat-free mass in PreC. Protein intake was high during both periods, while lipid and carbohydrate intakes were reduced ∼50% in PreC. Almost all athletes consumed 100% of the Recommended Dietary Allowance (RDA) for micronutrients in OffS, while 45% and 75% of the athletes had intakes below the RDA for vitamins A and E in PreC. Oxidative damage to lipids (thiobarbituric acid reactive substances, TBARS), protein carbonyls, and the TBARS/total antioxidant capacity ratio increased in PreC (32%, 27%, 60%), as did plasma tumor necrosis factor α (4-fold) and WURSS-21 scores (25%). There were no significant changes in serum catalase, glutathione reductase, and superoxide dismutase activities nor in interleukin 1β and immunoglobulins. In PreC, POMS showed negative changes in vigor (-20%), fatigue (23%), and total mood disturbance (35%), and RESTQ-Sport showed alterations for general and sport stress (34% and 50%, respectively) and sport recovery (-23%). Thus, PreC negatively affects nutrient intake, which may worsen oxidative stress, inflammation, psychological status, and the severity of respiratory infections in bodybuilders.

Acute metabolic responses following different resistance exercise protocols

Resistance exercise (RE) can be an excellent modality for glycemic control. Studies have demonstrated that a single RE session can reduce glycemia in subjects with or without diabetes. Little is known about the dose-response effect of RE on glycemic control. This study aimed to investigate the acute metabolic responses after different RE protocols. Eighty-nine males were separated into six groups that completed RE protocols: 2 sets of 18 repetitions (2 × 18 at 50% of 1-repetition maximum (1RM); n = 19); 3 sets of 12 repetitions (3 × 12 at 70% of 1RM; n = 14); 4 sets of 9 repetitions (4 × 9 at 80% of 1RM; n = 13); 6 sets of 6 repetitions (6 × 6 at 90% of 1RM; n = 19); circuit (2 × 18 at 50% of 1RM; n = 12); and a control session (n = 12). The exercise sequence consisted of 8 exercises. An oral glucose tolerance test was conducted with metabolic measurements immediately after each RE protocol and every 15 min until 120 min of recovery. All groups exhibited significantly lower values (p < 0.05) in the glucose area under the curve (AUC) when compared with control over a 120 min monitoring period. The 6 × 6 group showed a significantly lower glucose AUC versus the 3 × 12 and 4 × 9 groups (p = 0.004; p = 0.001, respectively). As for blood lactate, the control and 6 × 6 groups exhibited lower AUC values versus all other groups (p < 0.05), and AUC for glucose and lactate concentration showed a negative and significant correlation (r = -0.46; p < 0.0001). It appears that a combination of 9-12 repetitions per set and 3-4 sets per muscle group might be optimal for acute postprandial glucose control.

Moderate Resistance Training Attenuates the Increase in Blood Pressure and Decreases the Cardiomyocyte Nuclei Number in Hypertensive Rats

The left ventricle (LV) is a target organ for hypertension, responding with hypertrophy to constant overload pressure in the myocardium.1 Although hypertension is considered a strong determinant of LV hypertrophy (LVH), blood pressure (BP) can only explain limited interindividual variations in LV mass.1 Other important structural changes in the myocardium, such as cardiomyocyte hypertrophy and increase in fibroblast content and interstitial elements, are directly linked to LVH in spontaneously hypertensive rats (SHRs).2-4