Antônio Marcos Vargas da Silva

Functional electrical stimulation in the treatment of patients with chronic heart failure: a meta-analysis of randomized controlled trials.

Functional electrical stimulation (FES) produces beneficial effects in the treatment of patients with chronic heart failure (CHF), but studies carried out in these patients show small sample sizes and conflicting results. The aim of this metaanalysis was to systematically review the effect of treatment with FES compared with conventional aerobic exercise training (CA) or control group in patients with CHF. The search strategy included MEDLINE, LILACS, Physiotherapy Evidence Database and Cochrane Library. Randomized trials comparing FES versus CA or control group in the treatment of patients with CHF were included. Two reviewers independently extracted the data. Main analysis used a fixed-effects model. The search retrieved 794 articles, from which seven studies were included. Treatment with FES provided a smaller gain in peak VO2 compared with CA] − 0.74 ml/kg per min [95% confidence interval (CI): − 1.38 to − 0.10]}. There was no difference in the muscle strength [− 0.33Nm (95% CI: − 4.56 to 3.90)] and in the distance of the 6-min walk test [2.73m (95% CI: − 15.39 to 20.85)] on comparing FES with CA. An increase in peak VO2 of 2.78 ml/kg per min (95% CI: 1.44-4.13) was observed in FES versus the control group. Treatment with FES provides a similar gain in the distance of the 6-min walk test and in the muscle strength when compared with CA, but a small gain in the peak VO2. An increase in the peak VO2 can be obtained with FES as compared with the control group. Thus, FES may be an alternative in relation with CA for patients with CHF and with those who are unable to perform this kind of exercise. Eur J Cardiovasc Prev Rehabil 17:254-260

Endothelial Dysfunction Is Related to Poor Glycemic Control in Adolescents with Type 1 Diabetes under 5 Years of Disease: Evidence of Metabolic Memory

CONTEXT The relation between endothelial dysfunction (ED), glycemic control, and early type I diabetes mellitus (T1DM) is unclear. OBJECTIVE The objective of the study was to evaluate the association of ED, glycemic control, and the duration of diabetes in T1DM. DESIGN This was a cross-sectional study. SETTING The study was conducted at a public outpatient clinic. PATIENTS Fifty-seven T1DM adolescents and 10 healthy age-matched controls participated in the study. INTERVENTION There were no interventions. METHODS AND OUTCOME MEASURES Endothelial function (ED) was evaluated by flow-mediated dilation (FMD) in the brachial artery after reactive hyperemia. Biochemical data, including HbA1c (glycohemoglobin), high-sensitivity C-reactive protein, lipids, and urinary albumin excretion were collected. Means of four HbA1c values collected at 3-month intervals in the first and second year before FMD analyses were obtained. RESULTS Mean FMD was decreased in T1DM compared with controls (P = 0.023), independent of age, smoking, hypertension, or dyslipidemia. Twenty-eight of 57 T1DM patients enrolled (49%) had ED. FMD was decreased in microalbuminuric (4.1%) compared with normoalbuminuric patients (10.1%, P = 0.01) and controls (14.6%, P < 0.001). FMD correlated inversely with mean second-year HbA1c (r = -0.426, P = 0.02), particularly in patients with less than 5 yr of T1DM (r = -0.61, P = 0.004). In these patients, high-sensitivity C-reactive protein was strongly correlated with mean first-year HbA1c (r = -0.66, P = 0.0003). In patients with more than 5 yr of T1DM, we found no significant correlations between ED and glycemic control. CONCLUSIONS Endothelial dysfunction is common in T1DM adolescents with less than 5 yr of disease. It is associated with duration of disease, microalbuminuria, and mean second-year HbA1c but not with mean first-year HbA1c. These data support the metabolic memory hypothesis.

Prognostic value of the six-minute walk test in end-stage renal disease life expectancy: a prospective cohort study

OBJECTIVES: The six-minute walk test has been widely used to evaluate functional capacity and predict mortality in several populations. Thus, the aim of this study was to evaluate the prognostic value of the six-minute walk test for the life expectancy of end-stage renal disease patients. METHODS: Patients over 18 years old who underwent hemodialysis for at least six months were included. Patients with hemodynamic instability, smoking, chronic obstructive pulmonary disease, physical incapacity and acute myocardial stroke in the preceding three months were excluded. RESULTS: Fifty-two patients (54% males; 36±11 years old) were followed for 144 months. The distance walked in the six-minute walk test was a survival predictor for end-stage renal disease patients. In the multivariate analysis, for each 100 meters walked with a 100-meter increment, the hazard ratio was 0.53, with a 95% confidence interval of 0.37-0.74. There was a positive correlation between the distance walked in the six-minute walk test and peak oxygen consumption (r = 0.508). In the multivariate analysis, each year of dialysis treatment represented a 10% increase in death probability; in the severity index analysis, each point on the scale represented an 11% increase in the death risk. CONCLUSIONS: We observed that survival increased approximately 5% for every 100 meters walked in the six-minute walk test, demonstrating that the test is a viable option for evaluating the functional capacity in patients with end-stage renal disease.

Relationship between anthropometric measures and cardiovascular risk factors in children and adolescents.

Background Obesity has been identified as an important risk factor in the development of cardiovascular diseases; however, other factors, combined or not with obesity, can influence cardiovascular risk and should be considered in cardiovascular risk stratification in pediatrics. Objective To analyze the association between anthropometry measures and cardiovascular risk factors, to investigate the determinants to changes in blood pressure (BP), and to propose a prediction equation to waist circumference (WC) in children and adolescents. Methods We evaluated 1,950 children and adolescents, aged 7 to 18 years. Visceral fat was assessed by WC and waist hip relationship, BP and body mass index (BMI). In a randomly selected subsample of these volunteers (n = 578), total cholesterol, glucose and triglycerides levels were evaluated. Results WC was positively correlated with BMI (r = 0.85; p < 0.001) and BP (SBP r = 0.45 and DBP = 0.37; p < 0.001). Glycaemia and triglycerides showed a weak correlation with WC (r = 0.110; p = 0.008 e r = 0.201; p < 0.001, respectively). Total cholesterol did not correlate with any of the variables. Age, BMI and WC were significant predictors on the regression models for BP (p < 0.001). We propose a WC prediction equation for children and adolescents: boys: y = 17.243 + 0.316 (height in cm); girls: y = 25.197 + 0.256 (height in cm). Conclusion WC is associated with cardiovascular risk factors and presents itself as a risk factor predictor of hypertension in children and adolescents. The WC prediction equation proposed by us should be tested in future studies.

Haematological effect of pulsed ultrasound in acute muscular inflammation in rats.

OBJECTIVE To evaluate the effect of low-intensity pulsed ultrasound (LIPUS) on the haematological dynamics of an acute inflammatory process after an iatrogenic muscular lesion. DESIGN Controlled laboratory study. SETTING Research laboratory. PARTICIPANTS Eighteen male Wistar rats (weight 350 to 450g) were submitted to surgical incision in the biceps femoris muscle (approximately 50%), and subsequently subdivided into control (n=9) and LIPUS (n=9) groups. INTERVENTION Ultrasound (1.0MHz) was applied at the lesion site in the pulsed mode (2ms on, 8ms off) at 0.4W/cm(2) for 3 minutes at 1, 8 and 24 hours post-surgery. MAIN OUTCOME MEASURES In these periods, blood was collected through venepuncture of the retro-orbital plexus and evaluated for different types of leukocytes and erythrocytes. RESULTS LIPUS reduced the total leukocyte count at 1, 8 and 24 hours post-surgery (1 hour, control 9017.2±481×10(3)/mm(3) vs LIPUS 6189.8±450×10(3)/mm(3); 8 hours, control 8078.2±501×10(3)/mm(3) vs LIPUS 5371.3±378×10(3)/mm(3); 24 hours, control 8192.3±646×10(3)/mm(3) vs LIPUS 6059.1±503×10(3)/mm(3); P<0.001). The monocyte count was reduced at 8 and 24 hours post-surgery (8 hours, control 815.5±126×10(3)/mm(3) vs LIPUS 375.4±70×10(3)/mm(3); 24 hours, control 875.3±124×10(3)/mm(3) vs LIPUS 564.7±56×10(3)/mm(3); P<0.001). The number of segmented neutrophils was only reduced at 1 hour post-surgery (control 5033.1±397×10(3)/mm(3) vs LIPUS 3594.8±191×10(3)/mm(3); P=0.006), and the lymphocyte count was only reduced at 8 hours post-surgery (control 4759.7±459×10(3)/mm(3) vs LIPUS 2584.1±356×10(3)/mm(3); P=0.003). Changes were not observed in the concentrations of young neutrophils, polibocytes and erythrocytes. CONCLUSION LIPUS reduced aspects of the inflammatory process following an acute incisional muscular lesion.

Força muscular respiratória e capacidade funcional na insuficiência renal terminal

OBJECTIVE: to evaluate the association of respiratory muscle strength with functional capacity, lower limb strength and biochemical variables in hemodialysis (HD) patients. METHODS: a cross-sectional study involving 30 patients (18 male), 53.4 ± 12.9 years, 41.1 ± 55.7 months on HD therapy. Maximal inspiratory pressure (PImax), maximal expiratory pressure (PEmax), distance completed in a six-minute walk test (6MWT) and number of repetitions in sit-and-stand test (STST) were evaluated. The biochemical variables were recorded in the database routine work service. RESULTS: LogEPmax and 6MWT values were significantly lower than the predicted values (p = 0.015; p < 0.001, respectively). logPImax and logPEmax were correlated with number of repetitions in STST (r = 0.476, p = 0.008; r = 0.540, p = 0.002, respectively) and with phosphorus blood levels (r = 0.422, p = 0.020; r = 0.639, p < 0.001, respectively). 6MWT was correlated with logPEmax (r = 0.511; p = 0.004) and with number of repetitions in STST (r = 0.561; p = 0.001). CONCLUSION: PEmax reduction in patients with ESRD on HD is associated with functional capacity, lower limb strength and phosphorus blood levels, and may at least partly represent the low physical and functional performance of these patients.

Reversal of postprandial endothelial dysfunction by cyclooxygenase inhibition in healthy volunteers.

The aim of this study was to evaluate the role of cyclooxygenase (COX) in venous vascular reactivity changes after an oral lipid overload (OLO). Venous endothelial function (dorsal hand vein technique) was evaluated in fasting, 30 minutes after COX inhibition (aspirin-fasting), 2 to 4 hours after an OLO (1000 kcal, 58% fat), and again after COX inhibition (aspirin-OLO, 600 mg/200 mL water) in 10 healthy adults (age, 28.1 ± 1.3 years; body mass index, 22.3 ± 0.6 kg/m2). Fasting, 2- to 4-hour post-OLO, and 60-minute postaspirin plasma glucose, insulin, and lipids were also evaluated. The OLO increased triglycerides and insulin, reduced low-density lipoprotein and high-density lipoprotein, but glycemia and total cholesterol remained unchanged. There were no metabolic differences between OLO and aspirin-OLO. In fasting, aspirin reduced acetylcholine-induced venodilation (107.0% ± 14% versus 57.3% ± 11%; P < 0.001). Vascular reactivity was blunted after the OLO (phenylephrine dose: 0.3 ± 0.2 fasting versus 1.9 ± 0.8 nmol/min after OLO; P < 0.001) and was partially corrected by aspirin (0.4 ± 0.2; P < 0.001). Similar changes were observed in maximum venodilation after acetylcholine (107.0% ± 14% fasting versus 60.4% ± 9% after OLO, P < 0.001; aspirin-OLO: 95.9% ± 6%; P < 0.001). The responses to sodium nitroprusside remained unchanged during the study. We conclude that the OLO reduction in the endothelium-dependent venoconstriction and venodilation is partially the result of the action of COX.

Insulin therapy does not interfere with venous endothelial function evaluation in patients with type 2 diabetes mellitus

INTRODUCTION: Endothelium-dependent dilation is improved in insulin-treated diabetic patients, but this effect is probably due to improved glycemic control. The objective of the present study was to compare endothelium-dependent dilation in patients with well-controlled type 2 diabetes who are or are not using insulin as part of their therapy. METHODS: We studied 27 patients with type 2 diabetes (11 women, 60.3 years ± 6 years, with HbA1c < 7% and no nephropathy), including 16 patients treated with anti-diabetic agents (No-Ins, 8 women) and 11 patients treated with insulin alone or in combination with anti-diabetic agents (Ins, 3 women). Endothelial function was evaluated by the dorsal hand vein technique, which measures changes in vein diameter in response to phenylephrine, acetylcholine (endothelium-dependent vasodilation) and sodium nitroprusside (endothelium-independent vasodilation). RESULTS: Age, systolic blood pressure (No-Ins: 129.4 mmHg ± 11.8 mmHg, Ins: 134.8 mmHg ± 12.0 mmHg; P =  0.257), HbA1c, lipids and urinary albumin excretion rate [No-Ins: 9 mg/24 h (0-14.1 mg/24 h) vs. Ins: 10.6 mg/24 h (7.5-14.4 mg/24 h), P = 0.398] were similar between groups. There was no difference between endothelium-dependent vasodilation of the No-Ins group (59.3% ± 26.5%) vs. the Ins group (54.0% ± 16.3%; P = 0.526). Endothelium-independent vasodilation was also similar between the No-Ins (113.7% ± 35.3%) and Ins groups (111.9% ± 28.5%; P = 0.888). CONCLUSIONS: Subcutaneous insulin therapy does not interfere with venous endothelial function in type 2 diabetes when glycemic and blood pressure control are stable.

Espirometria de incentivo a volume versus a fluxo sobre parâmetros respiratórios em idosos

En el proceso de envejecimiento, el individuo pasa por cambios fisiologicos, destacandose la declinacion de la funcion pulmonar. La espirometria de incentivo, utilizada en diversas poblaciones, aun no deja clara la diferencia entre los metodos a volumen y a flujo sobre variables respiratorias en sujetos anosos. El objetivo fue comparar los efectos de la espirometria de incentivo - volumen y flujo, sobre la funcion pulmonar, fuerza muscular respiratoria y movilidad toraco-abdominal de anosos sanos. Este fue un ensayo clinico con 48 anosos, entre 60 y 84 anos de edad, randomizados para espirometria de incentivo a volumen (n=23) o a flujo (n=25). Fueron evaluadas las presiones inspiratoria (PImax) y expiratoria (PEmax) maximas, volumenes y capacidades pulmonares y cirtometria toraco-abdominal pre y post entrenamiento domiciliario. Los datos fueron analizados por el analisis de varianza de dos vias con medidas repetidas. Hubo aumento de la PImax, PEmax, capacidad vital forzada (CVF), volumen expiratorio forzado en el primer segundo, volumen minuto, volumen corriente y cirtometria a nivel xifoides y umbilical en ambos grupos (p<0,001). En la comparacion entre los grupos, el aumento en la CVF fue mayor en el grupo flujo (p=0,03) y mayor cirtometria axilar en el grupo volumen (p=0,02). Ambos incentivadores fueron eficaces en la mejora de la funcion pulmonar, fuerza muscular respiratoria y movilidad toraco-abdominal en anosos sanos, mostrandose buenos aliados de la fisioterapia respiratoria.

Disfunção endotelial no diabetes melito e estados de resistência à insulina: papel do estresse oxidativo e potenciais oportunidades terapêuticas

O endotelio cumpre sua funcao de manutencao do tonus vascular pela liberacao de substâncias vasodilatadoras (a principal delas, o oxido nitrico – NO, gerado a partir do metabolismo da L-arginina pela NO sintase endotelial, eNOS) e vasoconstritoras, que, quando liberadas em desequilibrio, geram disfuncao endotelial. A disfuncao endotelial esta presente em estados patologicos, tais como no diabetes melito (DM), na sindrome metabolica, na hipertensao arterial, na dislipidemia etc., contribuindo para o desenvolvimento da aterosclerose caracteristica dessas doencas por promover inflamacao, trombose, rigidez arterial e reducao da regulacao do tonus e fluxo arteriais (1). Sua presenca e preditora de eventos cardiovasculares (2), surge nas fases iniciais da doenca aterosclerotica e pode ser revertida por meio de medidas terapeuticas que sabidamente sao capazes de reduzir a evolucao dessa doenca, tais como exercicio fisico, melhora da hiperglicemia do DM (3), cessacao do fumo (4), uso de estatinas, entre outras. Sao mecanismos causais da disfuncao endotelial nos estados de resistencia a insulina e DM: alteracao de vias de sinalizacao que levam a inativacao da eNOS, ativacao do endotelio por moleculas pro-inflamatorias, disfuncao mitocondrial e aumento do estresse oxidativo na vasculatura (1), os quais podem ser particularmente importantes de acordo com fatores geneticos predisponentes (5). O estresse oxidativo e induzido pelas especies reativas de oxigenio (EROs) e o ânion superoxido reage com o NO para formar peroxinitrito, substância altamente reativa. Dados do nosso grupo em pacientes com insuficiencia renal cronica mostraram correlacao inversa entre a capacidade antioxidante total e a funcao endotelial avaliada no leito venoso (6), o que reforca outros dados da literatura de relacao causal entre disfuncao endotelial e estresse oxidativo. A exposicao da vasculatura a hiperglicemia e o aumento de acidos graxos livres caracteristicos do DM e estados de resistencia insulinica induzem a producao de superoxido e reduzem a biodisponibilidade de NO, o que pode ser restaurado por tratamentos antioxidantes em algumas situacoes, e nao em outras, tal como visto em estudo publicado por Capellini e cols. neste numero dos ABE&M (7). E interessante observar que, apesar de numerosos dados experimentais mostrando que o estresse oxidativo contribui para a disfuncao endotelial (4), os ensaios clinicos realizados em humanos nao mostraram beneficio de tratamentos com antioxidantes sobre desfechos cardiovasculares (8). Naturalmente que a implementacao de um tratamento inovador requer que, alem de sua comprovacao em modelos animais, este seja reprodutivel em seres humanos e testado em grandes ensaios clinicos randomizados, que permitam avaliar 1 Professora adjunta do Departamento de Medicina Interna, Faculdade de Medicina e Programa de Pos-Graduacao em Ciencias Medicas/Endocrinologia, Universidade Federal do Rio Grande do Sul (UFRGS) e Servico de Endocrinologia, Hospital de Clinicas de Porto Alegre, RS, Brasil 2 Professor adjunto do Departamento de Fisioterapia e Reabilitacao, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brasil 3 Professora livre-docente do Departamento de Cardiopneumologia, Faculdade de Medicina da Universidade de Sao Paulo (FMUSP), Sao Paulo, SP, Brasil