The burden of physical inactivity for the public health care system in Brazil

OBJECTIVE: To update the estimated cost of physical inactivity for the Brazilian Unified Health System (SUS). METHODS: The hospitalization costs were accessed via a database of the Ministry of Health – Informatics Department of the Brazilian SUS. Physical inactivity for the year 2017 was accessed via the Sistema de Vigilância de Fatores de Risco e Proteção para Doenças Crônicas por Inquérito Telefônico (Vigitel – Surveillance System for Risk and Protective Factors for Chronic Diseases by Telephone Survey). Seven chronic non-communicable diseases (NCD) were selected via the international classification of disease (ICD-10). The population fraction attributable to physical inactivity was calculated based on relative risk reported in previous studies and the prevalence of physical inactivity. RESULTS: In 2017, the seven NCD considered in the analysis were responsible for 154,017 hospital admissions in adults older than 40 years old, residing in the state capitals and the Federal District, which corresponded to 6.5% of hospitalizations and 10.6% of SUS costs at an estimated US$112,524,914.47. Considering the group of individuals with insufficient physical activity in their leisure time, the percentage cost attributed to physical inactivity reached 17.4$ 482 million, from which 17.4%, US$ 83 million were attributed to physical inactivity. CONCLUSION: This study provides evidence to conclude that physical inactivity exerts an economic impact on the SUS due to NCD hospitalization. Physical inactivity is a modifiable lifestyle and compelling evidence, including that of this article, supports the promotion of a more active community as one of the major targets of public health care policies

Muscle metaboreflex and cerebral blood flow regulation in humans:implications for exercise with blood flow restriction

We investigated the effect of activating metabolically sensitive skeletal muscle afferents (muscle metaboreflex) on cerebral blood flow and the potentially confounding influence of concomitant changes in the partial pressure of arterial carbon dioxide. Eleven healthy males (25 ± 4 yr) performed submaximal leg cycling exercise on a semirecumbent cycle ergometer (heart rate: ∼120 beats/min), and assessments were made of the partial pressure of end-tidal carbon dioxide (PetCO2), internal carotid artery blood flow (ICAQ) and conductance (ICACVC), and middle cerebral artery mean blood velocity (MCAvm) and conductance index (MCACVCi).The muscle metaboreflex was activated during cycling with leg blood flow restriction (BFR) or isolated with postexercise ischemia (PEI). In separate trials, PetCO2was either permitted to fluctuate spontaneously (control trial) or was clamped at 1 mmHg above resting levels (PetCO2clamp trial). In the control trial, leg cycling with BFR decreased PetCO2(Δ−4.8 ± 0.9 mmHg vs. leg cycling exercise) secondary to hyperventilation, while ICAQ, ICACVC, and MCAvmwere unchanged and MCACVCidecreased. However, in the PetCO2clamp trial, leg cycling with BFR increased both MCAvm(Δ5.9 ± 1.4 cm/s) and ICAQ(Δ20.0 ± 7.8 ml/min) and attenuated the decrease in MCACVCi, while ICACVCwas unchanged. In the control trial, PEI decreased PetCO2(Δ−7.0 ± 1.3 mmHg vs. rest), MCAvmand MCACVCi, whereas ICAQand ICACVCwere unchanged. In contrast, in the PetCO2clamp trial both ICAQ(Δ18.5 ± 11.9 ml/min) and MCAvm(Δ8.8 ± 2.0 cm/s) were elevated, while ICACVCand MCACVCiwere unchanged. In conclusion, when hyperventilation-related decreases in PetCO2are prevented the activation of metabolically sensitive skeletal muscle afferent fibers increases cerebral blood flow.</jats:p

Efeito agudo de uma sessão de exercício físico no controle autonômico cardíaco no ciclo circadiano

Background: In an independent way, the autonomic modulation is influenced by the circadian rhythm and metabolic activation of physical exercise. Although, is not know the interaction of circadian rhythm and physical exercise on cardiac autonomic modulation. Objective: Test the hypothesis that: 1. Cardiac autonomic modulation during physical exercise performed at three periods of the day morning, afternoon and night is similar. 2. Physical excise performed at morning, afternoon or night does not interfere on 24 hour cardiac autonomic modulation. Methods: We studied 10 healthy sedentary men (age = 24±3 years and BMI = 24±2 kg/m²). All volunteers performed three physical exercise sections with 30 minutes of duration, on cycle ergometer, with power on first metabolic threshold of maximal exercise test, on three periods of the day at morning (7 a.m.), afternoon (2 p.m.) and at night (10 p.m.). Each section was performed separated for at least 48 hours. Heart rate (Polar RS810) was record beat to beat, and HRV (FFT) was calculated, at rest for 10 minutes, during exercise and at 60 minutes recovery. The acute effect on cardiac autonomic control of three exercise sections was evaluated during 24 hours post physical exercise section, with Holter Cardio Light, and compared with control day, 24 hours with any kind of physical exercise, to test the differences was applied ANOVA two way for repeated measures and Tukey’s Post Hoc, and p≤0,05 for statistical significance. Results: For all sections, independent of the period of the day that physical exercise was performed, the heart rate and HRV was similar during physical exercise and during first hour of recovery. For the 24 hours subsequent to physical exercise, independent of the period of the day that physical exercise was performed the heart rate values and all HRV index was similar to control day. Conclusion: The cardiac autonomic control response to physical exercise on first ventilatory threshold and its recovery is not influenced by different periods of the day that physical exercise was performed. And, one physical exercise section, on first ventilatory threshold, did not interfere on cardiac autonomic control during 24 hours of recovery.Introdução: De forma independente, a modulação autonômica cardíaca sofre influência do ciclo circadiano e da ativação metabólica decorrente do exercício físico. Porém, não são conhecidos os efeitos da interação ciclo circadiano e exercício físico na modulação autonômica cardíaca. Objetivo: Testar as hipóteses de que: 1. A modulação autonômica cardíaca durante o exercício físico e recuperação pósexercício físico será semelhante nos períodos manhã, na tarde e na noite. 2. O exercício físico realizado nos períodos da manhã, tarde e noite não interfere na modulação autonômica cardíaca de 24 horas. Método: Foram avaliados 10 homens, sedentários e saudáveis (Idade = 24±3 anos e IMC = 24±2 kg/m²). Os voluntários realizaram três sessões de exercício físico, com carga obtida no primeiro limiar ventilatório, em três diferentes períodos do dia, manhã às 7 horas, tarde às 14 horas e noite às 22 horas. A frequência cardíaca (Polar RS810) e a VFC (FFT) foram analisadas, no repouso, durante o exercício físico e na recuperação pós-exercício físico. O efeito agudo das três sessões de exercício físico no controle autonômico cardíaco foi avaliado durante as 24 horas subsequêntes ao exercício físico, por meio do Holter Cardio Light, comparadas ao registro de 24 horas de um dia sem exercício físico (dia controle). Para testar as diferenças foi realizada análise de variância de dois caminhos, com post hoc de Tukey com diferenças significativas para p≤0,05. Resultados: Para todas as sessões de exercício físico, independente do período em que foi realizado, o comportamento da freqüência cardíaca e dos índices da VFC foram semelhantes durante a execução do exercício físico e durante a primeira hora de recuperação. Nas 24 horas subseqüentes ao exercício físico, independente do período do dia em que o exercício físico foi realizado, os valores de freqüência cardíaca e todos os índices da VFC foram similares ao do dia controle. Conclusão: A resposta autonômica cardíaca durante o exercício físico com carga do primeiro limiar metabólico e recuperação não sofrem interferência dos diferentes momentos do dia em que se realizou o exercício físico. E, uma sessão de exercício físico, realizada com carga obtida no primeiro limiar metabólico, não interferiu no controle autonômico cardíaco de 24 horas de recuperação

Diving and exercise:The interaction of trigeminal receptors and muscle metaboreceptors on muscle sympathetic nerve activity in humans

Swimming involves muscular activity and submersion, creating a conflict of autonomic reflexes elicited by the trigeminal receptors and skeletal muscle afferents. We sought to determine the autonomic cardiovascular responses to separate and concurrent stimulation of the trigeminal cutaneous receptors and metabolically sensitive skeletal muscle afferents (muscle metaboreflex). In eight healthy men (30 ± 2 yr) muscle sympathetic nerve activity (MSNA; microneurography), mean arterial pressure (MAP; Finometer), femoral artery blood flow (duplex Doppler ultrasonography), and femoral vascular conductance (femoral artery blood flow/MAP) were assessed during the following three experimental conditions: 1) facial cooling (trigeminal nerve stimulation), 2) postexercise ischemia (PEI; muscle metaboreflex activation) following isometric handgrip, and 3) trigeminal nerve stimulation with concurrent PEI. Trigeminal nerve stimulation produced significant increases in MSNA total activity (Δ347 ± 167%) and MAP (Δ21 ± 5%) and a reduction in femoral artery vascular conductance (Δ−17 ± 9%). PEI also evoked significant increases in MSNA total activity (Δ234 ± 83%) and MAP (Δ36 ± 4%) and a slight nonsignificant reduction in femoral artery vascular conductance (Δ−9 ± 12%). Trigeminal nerve stimulation with concurrent PEI evoked changes in MSNA total activity (Δ341 ± 96%), MAP (Δ39 ± 4%), and femoral artery vascular conductance (Δ−20 ± 9%) that were similar to those evoked by either separate trigeminal nerve stimulation or separate PEI. Thus, excitatory inputs from the trigeminal nerve and metabolically sensitive skeletal muscle afferents do not summate algebraically in eliciting a MSNA and cardiovascular response but rather exhibit synaptic occlusion, suggesting a high degree of convergent inputs on output neurons. </jats:p

Intrathecal fentanyl abolishes the exaggerated blood pressure response to cycling in hypertensive men

KEY POINTS: The increase in blood pressure observed during physical activities is exaggerated in patients with hypertension, exposing them to a higher cardiovascular risk. Neural signals from the skeletal muscles appear to be overactive, resulting in this abnormal response in hypertensive patients. In the present study, we tested whether the attenuation of these neural signals in hypertensive patients could normalize their abnormal increase in blood pressure during physical activity. Attenuation of the neural signals from the leg muscles with intrathecal fentanyl injection reduced the blood pressure of hypertensive men during cycling exercise to a level comparable to that of normotensive men. Skeletal muscle afferent overactivity causes the abnormal cardiovascular response to exercise and was reverted in this experimental model, appearing as potential target for treatment. ABSTRACT: Hypertensive patients present an exaggerated increase in blood pressure and an elevated cardiovascular risk during exercise. Although controversial, human studies suggest that group III and IV skeletal muscle afferents might contribute to this abnormal response. In the present study, we investigated whether attenuation of the group III and IV muscle afferent signal of hypertensive men eliminates the exaggerated increase in blood pressure occurring during exercise. Eight hypertensive men performed two sessions of 5 min of cycling exercise at 40 W. Between sessions, the subjects were provided with a lumbar intrathecal injection of fentanyl, a μ‐opioid receptor agonist, aiming to attenuate the central projection of opioid‐sensitive group III and IV muscle afferent nerves. The cardiovascular response to exercise of these subjects was compared with that of six normotensive men. During cycling, the hypertensive group demonstrated an exaggerated increase in blood pressure compared to the normotensive group (mean ± SEM: +17 ± 3 vs. +8 ± 1 mmHg, respectively; P < 0.05), whereas the increase in heart rate, stroke volume, cardiac output and vascular conductance was similar (P > 0.05). Fentanyl inhibited the blood pressure response to exercise in the hypertensive group (+11 ± 2 mmHg) to a level comparable to that of the normotensive group (P > 0.05). Moreover, fentanyl increased the responses of vascular conductance and stroke volume to exercise (P < 0.05), whereas the heart rate response was attenuated (P < 0.05) and the cardiac output response was maintained (P > 0.05). The results of the present study show that attenuation of the exercise pressor reflex normalizes the blood pressure response to cycling exercise in hypertensive individuals

BRIEF ISOCAPNIC HYPEROXIA INCREASES SYMPATHETIC VASCULAR TRANSDUCTION DURING SYMPATHOEXCITATORY MANEUVERS IN HEALTHY HUMANS

Sao Paulo Research Foundation (FAPESP)National Counsel of Technological and Scientific Development (CNPq)Research Support Foundation of the State of Rio de Janeiro (FAPERJ)Univ Fed Sao Paulo, Dept Physiol, Sao Paulo, SP, BrazilFluminense Fed Univ, Dept Physiol & Pharmacol, Niteroi, RJ, BrazilUniv Brasilia, Fac Phys Educ, Brasilia, DF, BrazilUniv Fed Sao Paulo, Dept Physiol, Sao Paulo, SP, BrazilWeb of Scienc