Improvements in Heart Rate Variability in Women with Obesity: Short-term Effects of Sleeve Gastrectomy.

PURPOSE: Obesity has been associated with reduced vagal function and increased sympathetic activity. Cardiac autonomic dysfunction has emerged as a major risk factor in the development of cardiovascular disease. Cardiac autonomic function (CAF) can be assessed by heart rate variability (HRV), an independent predictor of mortality based on changes in time intervals between adjacent heartbeats (RR). Bariatric surgery is considered the most effective treatment for obesity and its comorbidities, with sleeve gastrectomy (SG) being the most frequent bariatric procedure. There are few studies on HRV changes in women with obesity after SG. The aim of this study was to evaluate the short-term impact of SG on CAF and its relationship with weight loss. MATERIALS AND METHODS: An observational cohort study was conducted. Twenty-three female patients were assessed before SG and at 1 and 3 months after surgery. CAF was evaluated by analyzing HRV from 5-min records of RR intervals while the subject was supine. HRV was analyzed in time and frequency domains and with a nonlinear method. RESULTS: Patients (36.0 ± 11.1 years old, BMI 35.1 ± 3.4 kg/m2) presented higher HRV values, on average, in all domains both at 1 and 3 months after SG (p < 0.05). In addition, all anthropometric parameters improved (p < 0.001) although there was no relationship between HRV improvements and anthropometric changes. CONCLUSION: SG seems to be effective at reducing excess weight and improving HRV at the short term, and these changes are detectable as early as the first month after surgery. HRV assessment appears as a promising low-cost tool that deserves further research.

Physical fitness and physical activity in women with obesity: short term effects of sleeve gastrectomy / Condición física y actividad física en mujeres con obesidad: efectos a corto plazo de una gastrectomía vertical

Introduction: the increase on prevalence of obesity has been linked to a higher number of bariatric surgeries, being sleeve gastrectomy (SG) the most frequent bariatric procedures in the world. However, there are few studies that determine the impact of SG on health's determinants such as physical fitness (PF) and physical activity (PA). Objectives: to describe the changes in PF and PA of patients after SG. Methods: twenty-three women with obesity (mean 36.1 ± 11.1 years old and body mass index [BMI] of 35.1 ± 3.4 kg/m2) were evaluated preoperatively to SG and at one and three months after surgery. An assessment of PF was conducted, including handgrip (HGS) and quadriceps muscle strength (QMS) with dynamometers and cardiorespiratory fitness (CRF) with an ergospirometer. PA was assessed with a three-axis accelerometer. Results: the absolute VO2 peak decreased after the first and third month (p < 0.001) post SG. The VO2 peak relative to body weight showed an increase from baseline after the SG (p = 0.002). After SG, there was a reduction in absolute values for HGS and QMS (p < 0.001) and an increase in relative HGS after three months post-surgery compared to preoperative (p = 0.011), without changes in relative QMS (p = 0.596). No changes in PA were observed. Conclusions: after SG, there is a short term decline on PF when it is expressed on absolute values. However, when it is expressed in relative terms to body weight, some components of PF improve, while others showed no change. There was no modification in PA levels of the participants

Introducción: el incremento en la prevalencia de la obesidad se ha relacionado con un mayor número de cirugías bariátricas, siendo la gastrectomía vertical (SG) el procedimiento bariátrico más frecuente en el mundo. Sin embargo, hay pocos estudios que analicen el impacto de la SG en determinantes de la salud, como la condición física (PF) y la actividad física (PA). Objetivo: describir los cambios en la PF y la PA después de la SG. Métodos: veintitrés mujeres con obesidad (36,1 ± 11,1 años e índice de masa corporal [IMC] de 35,1 ± 3,4 kg/m2) fueron evaluadas previo a una SG y al primer y tercer mes postoperatorio. Las evaluaciones incluyeron la valoración de fuerza de prensión manual (HGS) y de cuádriceps (QMS) con dinamómetros y de capacidad cardiorrespiratoria (CRF) con ergoespirometría. La PA fue evaluada con acelerómetros triaxiales. Resultados: el VO2 peak absoluto disminuyó al primer y tercer mes (p < 0,001) luego de la SG. El VO2 peak relativo al peso corporal aumentó después de la SG (p = 0,002). Luego de la cirugía disminuyeron HGS y QMS absolutas (p < 0,001) y aumentó HGS relativa al peso corporal al tercer mes postoperatorio (p = 0,011), sin cambios en QMS relativa (p = 0,559). No se observaron cambios en la PA posterior a SG. Conclusiones: después de SG hay un deterioro a corto plazo de la PF expresada en términos absolutos, pero al expresarse en relación al peso corporal, algunos componentes de la PF no cambian y otros mejoran. No se observaron cambios en la PA poscirugía

[Oxygen uptake kinetics to assess cardiorespiratory fitness in obese patients]. / Uso de la cinética del consumo de oxígeno para la evaluación de la capacidad cardiorrespiratoria en pacientes con obesidad.

BACKGROUND: The evaluation of cardiorespiratory fitness (RCC) using maximal or peak oxygen consumption (VO2), requires a high level of effort in obese patients. We propose a method to evaluate RCC using constant and moderate loads, called VO2 kinetics (tau). AIM: To determine the relationship between tau and peak VO2 in patients with obesity. MATERIAL AND METHODS: Forty patients (87% females) aged 37 ± 12 years and with a body mass index (BMI) of 34.6 ± 4.0 kg/m2, were divided into two groups according to the applied workload (0.5 and 0.8 Watts/kg body mass) using a cycle ergometer and Cortex Metalyzer 3b equipment. The protocol was started with 6 minutes at constant load and then increments of 20-25 Watts every two min were made until determination of the peak VO2. RESULTS: The tau value was 51.8 ± 17.6 s, the absolute peak VO2 was 2.0 ± 0.7 L/min and the relative peak VO2 was 26.6 ± 30.0 ml/kg/min. There was a significant difference of tau medians between the group that used 0.5 and 0.8 Watts/kg (p = 0.002) and a significant inverse correlation between the absolute peak VO2 and the tau value for a load of 0.5 Watts/kg (rho = -0.415, p = 0.0327). CONCLUSIONS: The higher tau value, the lower the peak VO2 of an obese patient. It is suggested to apply loads of 0.5 Watts/kg for a VO2 kinetics test in obese patients or in subjects who do not wish to carry out higher physiological demands with a non-invasive and low risk procedure.

Uso de la cinética del consumo de oxígeno para la evaluación de la capacidad cardiorrespiratoria en pacientes con obesidad / Oxygen uptake kinetics to assess cardiorespiratory fitness in obese patients

Background: The evaluation of cardiorespiratory fitness (RCC) using maximal or peak oxygen consumption (VO2), requires a high level of effort in obese patients. We propose a method to evaluate RCC using constant and moderate loads, called VO2 kinetics (tau). Aim: To determine the relationship between tau and peak VO2 in patients with obesity. Material and Methods: Forty patients (87% females) aged 37 ± 12 years and with a body mass index (BMI) of 34.6 ± 4.0 kg/m2, were divided into two groups according to the applied workload (0.5 and 0.8 Watts/kg body mass) using a cycle ergometer and Cortex Metalyzer 3b equipment. The protocol was started with 6 minutes at constant load and then increments of 20-25 Watts every two min were made until determination of the peak VO2. Results: The tau value was 51.8 ± 17.6 s, the absolute peak VO2 was 2.0 ± 0.7 L/min and the relative peak VO2 was 26.6 ± 30.0 ml/kg/min. There was a significant difference of tau medians between the group that used 0.5 and 0.8 Watts/kg (p = 0.002) and a significant inverse correlation between the absolute peak VO2 and the tau value for a load of 0.5 Watts/kg (rho = -0.415, p = 0.0327). Conclusions: The higher tau value, the lower the peak VO2 of an obese patient. It is suggested to apply loads of 0.5 Watts/kg for a VO2 kinetics test in obese patients or in subjects who do not wish to carry out higher physiological demands with a non-invasive and low risk procedure.