Efecto de Dos Protocolos de Intervención para el Incremento de Ejercicio Físico: Estudio Longitudinal / The Effect of Two Intervention Protocols to Increase Physical Exercise: Longitudinal Study

Resumen El objetivo de este estudio fue conocer el impacto de la estrategia de autorregulación de Contraste Mental e Intenciones de Implementación (MCII) como complemento de una intervención con base en el Enfoque del Proceso de Acción en Salud (HAPA) para realizar ejercicio. Fueron reclutados 76 participantes con sobrepeso (índice de masa corporal [IMC]≥25) que querían perder peso (Medad =40 años; MIMC=29). Los participantes fueron asignados al azar a dos condiciones: HAPA (n=36) y HAPA+MCII (n=40). Las variables de interés (horas de ejercicio auto reportadas, medidas corporales y salud psicológica con DASS-21 e IWQOL-Lite) se midieron al inicio, en la semana 6 y en la 12. Encontramos un aumento significativo en las horas de ejercicio y disminución significativa del IMC y IWQOL-Lite Estado Físico y Autoestima al comparar las ocasiones de medición para la muestra total. Se observaron mayores efectos del protocolo HAPA+MCII que del HAPA en las variables de estudio, con excepción de las variables Ansiedad del DASS-21 y Vida sexual del IWQOL-Lite. Sin embargo, en ningún caso las diferencias resultaron estadísticamente significativas. El estudio indica el papel fundamental que desempeñan la autoeficacia y su operacionalización en el logro de una intervención exitosa. Al combinar dos protocolos, se recomienda considerar el efecto de techo que se puede obtener con un solo protocolo.

Abstrac The objective of this study was to understand the impact of the Mental Contrasting and Implementation Intentions (MCII) self-regulation technique as a complement to an intervention based on the Health Action Process Approach (HAPA) to perform exercise. Seventy-six participants with body mass index (BMI) ≥25 who wanted to lose weight (Mage =40 years; MBMI =29) were recruited. Participants were randomized into two conditions: HAPA (n=36) and HAPA + MCII (n=40). The variables of interest (self-reported hours of exercise, body measurements and psychological health with DASS-21 and IWQOL-Lite) were measured at the beginning, in week 6 and in 12. We found a significant increase in the hours of exercise and significant decrease in BMI and IWQOL-Lite Physical Functioning and Self-esteem when comparing the occasions of measurement for the total sample. Greater effects of the HAPA + MCII protocol were observed than of the HAPA for the study variables, with the exception of the DASS-21 Anxiety and the IWQOL-Lite Sexual life. However, the differences were not statistically significant. The study indicates the important role of self-efficacy and its operationalization for a successful intervention. When combining two protocols, the ceiling effect that can be obtained with a single protocol should be considered.

Dependence of Heart Rate Variability Indices on the Mean Heart Rate in Women with Well-Controlled Type 2 Diabetes.

Heart rate variability (HRV) is a method used to evaluate the presence of cardiac autonomic neuropathy (CAN) because it is usually attributed to oscillations in cardiac autonomic nerve activity. Recent studies in other pathologies suggest that HRV indices are strongly related to mean heart rate, and this does not depend on autonomic activity only. This study aimed to evaluate the correlation between the mean heart rate and the HRV indices in women patients with well-controlled T2DM and a control group. HRV was evaluated in 19 T2DM women and 44 healthy women during basal supine position and two maneuvers: active standing and rhythmic breathing. Time-domain (SDNN, RMSSD, pNN20) and frequency-domain (LF, HF, LF/HF) indices were obtained. Our results show that meanNN, age, and the maneuvers are the main predictors of most HRV indices, while the diabetic condition was a predictor only for pNN20. Given the known reduced HRV in patients with T2DM, it is clinically important that much of the HRV indices are dependent on heart rate irrespective of the presence of T2DM. Moreover, the multiple regression analyses evidenced the multifactorial etiology of HRV.

Metabolic Physiological Networks: The Impact of Age.

Metabolic homeostasis emerges from the interplay between several feedback systems that regulate the physiological variables related to energy expenditure and energy availability, maintaining them within a certain range. Although it is well known how each individual physiological system functions, there is little research focused on how the integration and adjustment of multiple systems results in the generation of metabolic health. The aim here was to generate an integrative model of metabolism, seen as a physiological network, and study how it changes across the human lifespan. We used data from a transverse, community-based study of an ethnically and educationally diverse sample of 2572 adults. Each participant answered an extensive questionnaire and underwent anthropometric measurements (height, weight, and waist), fasting blood tests (glucose, HbA1c, basal insulin, cholesterol HDL, LDL, triglycerides, uric acid, urea, and creatinine), along with vital signs (axillar temperature, systolic, and diastolic blood pressure). The sample was divided into 6 groups of increasing age, beginning with less than 25 years and increasing by decades up to more than 65 years. In order to model metabolic homeostasis as a network, we used these 15 physiological variables as nodes and modeled the links between them, either as a continuous association of those variables, or as a dichotomic association of their corresponding pathological states. Weight and overweight emerged as the most influential nodes in both types of networks, while high betweenness parameters, such as triglycerides, uric acid and insulin, were shown to act as gatekeepers between the affected physiological systems. As age increases, the loss of metabolic homeostasis is revealed by changes in the network's topology that reflect changes in the system-wide interactions that, in turn, expose underlying health stages. Hence, specific structural properties of the network, such as weighted transitivity, i.e., the density of triangles in the network, can provide topological indicators of health that assess the whole state of the system. Overall, our findings show the importance of visualizing health as a network of organs and/or systems, and highlight the importance of triglycerides, insulin, uric acid and glucose as key biomarkers in the prevention of the development of metabolic disorders.

The Impact of Education and Age on Metabolic Disorders.

Metabolic disorders, such as obesity, elevated blood pressure, dyslipidemias, insulin resistance, hyperglycemia, and hyperuricemia have all been identified as risk factors for an epidemic of important and widespread chronic-degenerative diseases, such as type 2 diabetes and cardiovascular disease, that constitute some of the world's most important public health challenges. Their increasing prevalence can be associated with an aging population and to lifestyles within an obesogenic environment. Taking educational level as a proxy for lifestyle, and using both logistic and linear regressions, we study the relation between a wide set of metabolic biomarkers, and educational level, body mass index (BMI), age, and sex as correlates, in a population of 1,073 students, academic and non-academic staff at Mexico's largest university (UNAM). Controlling for BMI and sex, we consider educational level and age as complementary measures-degree and duration-of exposure to metabolic insults. Analyzing the role of education across a wide spectrum of educational levels (from primary school to doctoral degree), we show that higher education correlates to significantly better metabolic health when compared to lower levels, and is associated with significantly less risk for waist circumference, systolic blood pressure, glucose, glycosylated hemoglobin, triglycerides, high density lipoprotein and metabolic syndrome (all p < 0.05); but not for diastolic blood pressure, basal insulin, uric acid, low density lipoprotein, and total cholesterol. We classify each biomarker, and corresponding metabolic disorder, by its associated set of statistically significant correlates. Differences among the sets of significant correlates indicate various aetiologies and the need for targeted population-specific interventions. Thus, variables strongly linked to educational level are candidates for lifestyle change interventions. Hence, public policy efforts should be focused on those metabolic biomarkers strongly linked to education, while adopting a different approach for those biomarkers not linked as they may be poor targets for educational campaigns.

Heart Rate and Systolic Blood Pressure Variability in the Time Domain in Patients with Recent and Long-Standing Diabetes Mellitus.

Diabetes Mellitus (DM) affects the cardiovascular response of patients. To study this effect, interbeat intervals (IBI) and beat-to-beat systolic blood pressure (SBP) variability of patients during supine, standing and controlled breathing tests were analyzed in the time domain. Simultaneous noninvasive measurements of IBI and SBP for 30 recently diagnosed and 15 long-standing DM patients were compared with the results for 30 rigorously screened healthy subjects (control). A statistically significant distinction between control and diabetic subjects was provided by the standard deviation and the higher moments of the distributions (skewness, and kurtosis) with respect to the median. To compare IBI and SBP for different populations, we define a parameter, α, that combines the variability of the heart rate and the blood pressure, as the ratio of the radius of the moments for IBI and the same radius for SBP. As diabetes evolves, α decreases, standard deviation of the IBI detrended signal diminishes (heart rate signal becomes more "rigid"), skewness with respect to the median approaches zero (signal fluctuations gain symmetry), and kurtosis increases (fluctuations concentrate around the median). Diabetes produces not only a rigid heart rate, but also increases symmetry and has leptokurtic distributions. SBP time series exhibit the most variable behavior for recently diagnosed DM with platykurtic distributions. Under controlled breathing, SBP has symmetric distributions for DM patients, while control subjects have non-zero skewness. This may be due to a progressive decrease of parasympathetic and sympathetic activity to the heart and blood vessels as diabetes evolves.

Heart Rate and Systolic Blood Pressure Variability on Recently Diagnosed Diabetics / Variabilidade da Frequência Cardíaca e da Pressão Arterial Sistólica em Diabéticos com Diagnóstico Recente

Background:Diabetes affects approximately 250 million people in the world. Cardiovascular autonomic neuropathy is a common complication of diabetes that leads to severe postural hypotension, exercise intolerance, and increased incidence of silent myocardial infarction.Objective:To determine the variability of heart rate (HR) and systolic blood pressure (SBP) in recently diagnosed diabetic patients.Methods:The study included 30 patients with a diagnosis of type 2 diabetes of less than 2 years and 30 healthy controls. We used a Finapres® device to measure during five minutes beat-to-beat HR and blood pressure in three experimental conditions: supine position, standing position, and rhythmic breathing at 0.1 Hz. The results were analyzed in the time and frequency domains.Results:In the HR analysis, statistically significant differences were found in the time domain, specifically on short-term values such as standard deviation of NN intervals (SDNN), root mean square of successive differences (RMSSD), and number of pairs of successive NNs that differ by more than 50 ms (pNN50). In the BP analysis, there were no significant differences, but there was a sympathetic dominance in all three conditions. The baroreflex sensitivity (BRS) decreased in patients with early diabetes compared with healthy subjects during the standing maneuver.Conclusions:There is a decrease in HR variability in patients with early type 2 diabetes. No changes were observed in the BP analysis in the supine position, but there were changes in BRS with the standing maneuver, probably due to sympathetic hyperactivity.

Fundamento:O diabetes afeta aproximadamente 250 milhões de pessoas no mundo. A neuropatia autonômica cardiovascular é uma complicação comum do diabetes que leva à hipotensão postural grave, intolerância ao exercício e aumento na incidência de infarto do miocárdio silencioso.Objetivo:Determinar a variabilidade da frequência cardíaca (FC) e da pressão arterial sistólica (PAS) em pacientes diabéticos com diagnóstico recente.Métodos:O estudo incluiu 30 pacientes com diabetes tipo 2 diagnosticado há menos de 2 anos e 30 controles saudáveis. Nós utilizamos o dispositivo Finapres® para medir durante cinco minutos a FC batimento-a-batimento e a pressão arterial (PA) em três condições experimentais: posição supina, em pé e durante respiração rítmica na frequência de 0,1 Hz. Os resultados foram analisados nos domínios do tempo e da frequência.Resultados:Em relação à FC, foram encontradas diferenças estatisticamente significativas nos valores da análise do domínio do tempo, especificamente em valores determinados a curto prazo, tais como o desvio-padrão dos intervalos NN (DPNN), a raiz quadrada da média das diferenças sucessivas (RQMDS) para a FC e o número de pares de NNs sucessivos que diferem em mais de 50 ms (pNN50). Não houve diferença significativa na análise da PA, mas houve uma dominância simpática nas três condições. A sensibilidade do barorreflexo (SBR) esteve diminuída em pacientes com diabetes de início recente, em comparação aos indivíduos saudáveis durante execução da manobra na posição ortostática.Conclusões:Há uma diminuição na variabilidade da FC em pacientes com diabetes tipo 2 de início recente. Não foram observadas alterações na análise da PA na posição supina, mas a SBR apresentou mudança com a manobra em pé provavelmente causada por hiperatividade simpática.

Heart rate and systolic blood pressure variability on recently diagnosed diabetics.

BACKGROUND: Diabetes affects approximately 250 million people in the world. Cardiovascular autonomic neuropathy is a common complication of diabetes that leads to severe postural hypotension, exercise intolerance, and increased incidence of silent myocardial infarction. OBJECTIVE: To determine the variability of heart rate (HR) and systolic blood pressure (SBP) in recently diagnosed diabetic patients. METHODS: The study included 30 patients with a diagnosis of type 2 diabetes of less than 2 years and 30 healthy controls. We used a Finapres® device to measure during five minutes beat-to-beat HR and blood pressure in three experimental conditions: supine position, standing position, and rhythmic breathing at 0.1 Hz. The results were analyzed in the time and frequency domains. RESULTS: In the HR analysis, statistically significant differences were found in the time domain, specifically on short-term values such as standard deviation of NN intervals (SDNN), root mean square of successive differences (RMSSD), and number of pairs of successive NNs that differ by more than 50 ms (pNN50). In the BP analysis, there were no significant differences, but there was a sympathetic dominance in all three conditions. The baroreflex sensitivity (BRS) decreased in patients with early diabetes compared with healthy subjects during the standing maneuver. CONCLUSIONS: There is a decrease in HR variability in patients with early type 2 diabetes. No changes were observed in the BP analysis in the supine position, but there were changes in BRS with the standing maneuver, probably due to sympathetic hyperactivity.

Los barorreflejos arteriales cardiovagal, cardiosimpático y vasosimpático y el control neural de la presión arterial a corto plazo / The cardiovagal, cardiosympathetic and vasosympathetic arterial baroreflexes and the neural control of short-term blood pressure

Introducción. Los factores que modulan la presión arterial a corto plazo se encuentran puntualmente regulados para mantenerla dentro de valores de referencia. Esto se logra gracias a la existencia de mecanismos de autorregulación, tanto humorales como nerviosos. Los mecanismos neurogénicos son reflejos y su resultado se observa en cambios de presión arterial de forma inmediata, latido a latido. Desarrollo. Los reflejos nerviosos cardiovasculares se encuentran mediados por los barorreceptores arteriales, a través de los efectores cardiovagal, cardiosimpático y vasosimpático. El barorreceptor es estimulado cuando el volumen de sangre eyectado por el ventrículo distiende las paredes arteriales del seno carotídeo y la aorta proximal y estimula los mecanorreceptores situados en la adventicia de estos vasos. El estímulo aferente viaja hasta el núcleo del haz solitario en el bulbo raquídeo y otras áreas en el puente donde se integran estos reflejos y la parte eferente genera cambios compensatorios en la frecuencia cardíaca y el tono del músculo liso vascular. Esta modificación súbita es la responsable de la variabilidad de la presión arterial latido a latido (corto plazo). Conclusión. Se realiza una revisión sobre la historia, la fisiología y los experimentos de los barorreflejos cardiovagal, cardiosimpático y vasosimpático y su influencia en la variabilidad de la presión arterial a corto plazo (AU)

Introduction. The factors that control the blood pressure are punctually regulated to keep it in reference values. These are maintained through autoregulatory mechanisms, humoral, nervous and endothelial-related. The humoral mechanisms are complex and modify the long-term blood pressure, in the other hand, the neurogenic mechanisms, are reflexive and can be observed in beat-to-beat changes of blood pressure. Development. The nervous cardiovascular reflexes are mediated by high-pressure and low-pressure baroreceptors, as cardiovagal, cardiosympathetic and vasosympathetic. The arterial baroreceptor are stimulated when the blood volumeejected by the ventricle distend the arterial walls. The neural discharge travels to the autonomic centers in the brain stem and the result is the modification of the heart rate and the vascular smooth muscle tone. This sudden modification is the responsible of the beat-to-beat (short-term) blood pressure variability. Conclusion. A review was made on the history of the physiology and experiments of the cardiovagal, cardiosympathetic and vasosympathetic baroreflexes and its influence in the short-term blood pressure variability (AU)

[The cardiovagal, cardiosympathetic and vasosympathetic arterial baroreflexes and the neural control of short-term blood pressure]. / Los barorreflejos arteriales cardiovagal, cardiosimpatico y vasosimpatico y el control neural de la presion arterial a corto plazo.

INTRODUCTION: The factors that control the blood pressure are punctually regulated to keep it in reference values. These are maintained through autoregulatory mechanisms, humoral, nervous and endothelial-related. The humoral mechanisms are complex and modify the long-term blood pressure, in the other hand, the neurogenic mechanisms, are reflexive and can be observed in beat-to-beat changes of blood pressure. DEVELOPMENT: The nervous cardiovascular reflexes are mediated by high-pressure and low-pressure baroreceptors, as cardiovagal, cardiosympathetic and vasosympathetic. The arterial baroreceptor are stimulated when the blood volume-ejected by the ventricle distend the arterial walls. The neural discharge travels to the autonomic centers in the brain stem and the result is the modification of the heart rate and the vascular smooth muscle tone. This sudden modification is the responsible of the beat-to-beat (short-term) blood pressure variability. CONCLUSION: A review was made on the history of the physiology and experiments of the cardiovagal, cardiosympathetic and vasosympathetic baroreflexes and its influence in the short-term blood pressure variability.

TITLE: Los barorreflejos arteriales cardiovagal, cardiosimpatico y vasosimpatico y el control neural de la presion arterial a corto plazo.Introduccion. Los factores que modulan la presion arterial a corto plazo se encuentran puntualmente regulados para mantenerla dentro de valores de referencia. Esto se logra gracias a la existencia de mecanismos de autorregulacion, tanto humorales como nerviosos. Los mecanismos neurogenicos son reflejos y su resultado se observa en cambios de presion arterial de forma inmediata, latido a latido. Desarrollo. Los reflejos nerviosos cardiovasculares se encuentran mediados por los barorreceptores arteriales, a traves de los efectores cardiovagal, cardiosimpatico y vasosimpatico. El barorreceptor es estimulado cuando el volumen de sangre eyectado por el ventriculo distiende las paredes arteriales del seno carotideo y la aorta proximal y estimula los mecanorreceptores situados en la adventicia de estos vasos. El estimulo aferente viaja hasta el nucleo del haz solitario en el bulbo raquideo y otras areas en el puente donde se integran estos reflejos y la parte eferente genera cambios compensatorios en la frecuencia cardiaca y el tono del musculo liso vascular. Esta modificacion subita es la responsable de la variabilidad de la presion arterial latido a latido (corto plazo). Conclusion. Se realiza una revision sobre la historia, la fisiologia y los experimentos de los barorreflejos cardiovagal, cardiosimpatico y vasosimpatico y su influencia en la variabilidad de la presion arterial a corto plazo.

[Cortical spreading depolarization: a new pathophysiological mechanism in neurological diseases]. / Despolarización cortical extendida: un nuevo mecanismo fisiopatológico en las enfermedades neurológicas.

Cortical spreading depolarization is a wave of almost complete depolarization of the neuronal and glial cells that occurs in different neurological diseases such as migraine with aura, subarachnoid hemorrhage, intracerebral hemorrhage, head trauma and stroke. These depolarization waves are characterized by a change in the negative potential with an amplitude between -10 and -30mV, duration of ∼1min and changes in the ion homeostasis between the intra- and extracellular space. This results in neuronal edema and dendritic distortion. Under pathologic states of hypoperfusion, cortical spreading depolarization can produce oxidative stress, worsen hypoxia and induce neuronal death. This is due to intense arterial vasoconstriction produced by an inverse response called spreading ischemia. Only in the last years there has been an electrophysiological confirmation of cortical spreading depolarization in human brains. Occurrence of cortical spreading depolarization has been associated with worse outcome in patients. Currently, increased knowledge regarding the pathophysiologic mechanisms supports the hypothetical correlation of cortical spreading depolarization with brain damage in humans. There are diverse therapeutic alternatives that promise inhibition of cortical spreading depolarization and subsequent better outcomes.