No description available.

Introdução. A baixa capacidade aeróbia é um importante marcador de mau prognóstico e um forte preditor de risco de morte em pacientes encaminhados para o teste de esforço cardiopulmonar (TECP) por razões clínicas. O índice oxygen uptake efficiency slope (OUES), um novo índice de eficiência cardiorrespiratória, tem sido utilizado como marcador submáximo durante o TECP. Estudos recentes sugerem que a leptina pode desempenhar um papel importante na regulação da respiração e, consequentemente, o aumento dos níveis de leptina pode estar relacionado com a diminuição do OUES. No entanto, o impacto da síndrome metabólica (SMet) e da apneia obstrutiva do sono (AOS) no OUES é desconhecido. Objetivo. Investigar o comportamento do OUES em pacientes com SMet, associado ou não à AOS. Métodos. Foram estudados 73 pacientes com SMet (ATP-III), alocados em dois grupos de acordo com o índice de apneia/hipopneia (IAH) obtido na polissonografia noturna: SMet+AOS (IAH >= 15 eventos/hora, n=38, 49±1 anos, 33±0,6 kg/m2) e SMet-AOS (IAH < 15 eventos/hora, n=35, 46±1 anos, 31,8±0,6 kg/m2). Um grupo controle saudável (CS, n=20, 47±1 anos, 26,1±0,8 kg/m2), pareado por idade e gênero, foi também estudado. Os pacientes realizaram as seguintes avaliações: polissonografia; exames laboratoriais (glicemia, triglicérides, colesterol total e frações, leptina e proteína C-reativa); medidas antropométricas (altura, peso corporal, índice de massa corpórea, circunferência abdominal); composição corporal pela bioimpedância; medidas de pressão arterial; e TECP. Resultados. Ambos os grupos com SMet apresentaram prejuízo quando comparados ao grupo CS no peso, índice de massa corpórea e nos fatores de risco da SMet (circunferência abdominal, glicemia, triglicérides, HDL-c e pressão arterial sistólica e diastólica, P < 0,05). No TECP os grupos SMet+AOS e SMet-AOS apresentaram menores valores de consumo de oxigênio pico (VO2pico, 22,2±0,7; 21,7±0,9 e 28,0±1,1 ml/kg/min, respectivamente, Interação; P < 0,001) comparados com CS. Da mesma forma, os grupos SMet tiveram menores: VO2 no limiar anaeróbio (VO2LA), na relação VO2 e carga de trabalho (deltaVO2/deltaW) e no OUES (25,3±0,8; 25,0±0,9 e 31,1±1,2; Interação; P < 0.001) quando comparado com CS. Em análises posteriores, o OUES se correlacionou apenas com a massa gorda e com a leptina (R=-0,35; P=0,006). Conclusão. Independente da presença da AOS, pacientes com SMet apresentam diminuição da eficiência cardiorrespiratória. Os níveis elevados de leptina pode ser uma das explicações para essa diminuição nesses pacientes / Introduction. Low aerobic capacity is an important marker of poor prognosis and a strong predictor of risk of death in patients referred for cardiopulmonary exercise testing (CPET) for clinical reasons. The oxygen uptake efficiency slopes (OUES), a new cardiorespiratory efficiency index, has been used as a submaximal marker during CPET. Recent studies suggest that leptin may play an important role in regulating respiration, and consequently, increased levels of leptin may be related to decreased OUES. However, the impact of metabolic syndrome (MetS) and obstructive sleep apnea (OSA) in the OUES is unknown. Objective. To investigate the OUES in MetS patients with or without OSA. Methods. We studied 73 patients with MetS (ATP-III), allocated into two groups according to apnea/hypopnea index (AHI), assessed by nocturnal polysomnography: MetS+OSA (AHI >= 15 events/hour, n=38, 49±1 years, 33±0.6 kg/m2) and MetS-OSA (AHI < 15 events/hour, n=35, 46±1 years, 32±0.6 kg/m2). A healthy control group (CG, n=20, 47±1 years, 26.1±0.8 kg/m2), matched for age and gender, was also studied. The patients performed the following evaluations: polysomnography; Laboratory tests (glycemia, triglycerides, total cholesterol and fractions, leptin and C-reactive protein); Anthropometric measurements (height, body weight, body mass index, waist circumference); Body composition by bioimpedance; Blood pressure measurements; and CPET. Results. Both MetS groups had impairment in weight, body mass index, and MetS risk factors (waist circumference, glycemia, triglycerides, HDL-c and systolic and diastolic blood pressure, P < 0.05) compared with CG. MetS+OSA and MetS-OSA groups presented lower values of peak oxygen consumption (VO2peak, 22.2±0.7, 21.7±0.9 and 28.0±1.1 ml/kg/min, respectively; Interaction; P < 0.001) compared to CG. In the same way, MetS groups had lowest: VO2 at anaerobic threshold (VO2LA), ratio of VO2 and workload (deltaVO2/deltaW) and OUES (25.3±0.8, 25.0±0.9 and 31.1±1.2, Interaction; P < 0.001) compared with CG. In further analyzes, OUES correlated only with fat mass and leptin (R =-0.35, P =0.006). Conclusion. Regardless of the presence of OSA, MetS patients present decreased cardiorespiratory efficiency. Elevated levels of leptin may be one of the explanations for this decrease in these patients

Rates of obesity (OB) are escalating among Canadian children and youth and the obesogenic environment is likely to cause further increases. An important aspect in providing clinical care to OB children is to have accurate assessment measures, particularly of their body composition and cardiorespiratory fitness. This project entails three interrelated projects aiming to develop novel cardiorespiratory fitness and body composition measurement techniques for an OB pediatric population. The purpose of the first project was to validate a new submaximal fitness protocol specifically geared towards OB children and youth. The second objective of this thesis involved assessing cardiorespiratory efficiency utilizing the Oxygen Uptake efficiency slope. The purpose of the third project was to determine the validity of a half-body scan methodology for measuring body composition in obese children and youth. The goal of developing these novel measurement techniques is improved design and evaluation of interventions aimed at managing pediatric obesity.

Rates of obesity (OB) are escalating among Canadian children and youth and the obesogenic environment is likely to cause further increases. An important aspect in providing clinical care to OB children is to have accurate assessment measures, particularly of their body composition and cardiorespiratory fitness. This project entails three interrelated projects aiming to develop novel cardiorespiratory fitness and body composition measurement techniques for an OB pediatric population. The purpose of the first project was to validate a new submaximal fitness protocol specifically geared towards OB children and youth. The second objective of this thesis involved assessing cardiorespiratory efficiency utilizing the Oxygen Uptake efficiency slope. The purpose of the third project was to determine the validity of a half-body scan methodology for measuring body composition in obese children and youth. The goal of developing these novel measurement techniques is improved design and evaluation of interventions aimed at managing pediatric obesity.

Rates of obesity (OB) are escalating among Canadian children and youth and the obesogenic environment is likely to cause further increases. An important aspect in providing clinical care to OB children is to have accurate assessment measures, particularly of their body composition and cardiorespiratory fitness. This project entails three interrelated projects aiming to develop novel cardiorespiratory fitness and body composition measurement techniques for an OB pediatric population. The purpose of the first project was to validate a new submaximal fitness protocol specifically geared towards OB children and youth. The second objective of this thesis involved assessing cardiorespiratory efficiency utilizing the Oxygen Uptake efficiency slope. The purpose of the third project was to determine the validity of a half-body scan methodology for measuring body composition in obese children and youth. The goal of developing these novel measurement techniques is improved design and evaluation of interventions aimed at managing pediatric obesity.

Introdução. A baixa capacidade aeróbia é um importante marcador de mau prognóstico e um forte preditor de risco de morte em pacientes encaminhados para o teste de esforço cardiopulmonar (TECP) por razões clínicas. O índice oxygen uptake efficiency slope (OUES), um novo índice de eficiência cardiorrespiratória, tem sido utilizado como marcador submáximo durante o TECP. Estudos recentes sugerem que a leptina pode desempenhar um papel importante na regulação da respiração e, consequentemente, o aumento dos níveis de leptina pode estar relacionado com a diminuição do OUES. No entanto, o impacto da síndrome metabólica (SMet) e da apneia obstrutiva do sono (AOS) no OUES é desconhecido. Objetivo. Investigar o comportamento do OUES em pacientes com SMet, associado ou não à AOS. Métodos. Foram estudados 73 pacientes com SMet (ATP-III), alocados em dois grupos de acordo com o índice de apneia/hipopneia (IAH) obtido na polissonografia noturna: SMet+AOS (IAH >= 15 eventos/hora, n=38, 49±1 anos, 33±0,6 kg/m2) e SMet-AOS (IAH < 15 eventos/hora, n=35, 46±1 anos, 31,8±0,6 kg/m2). Um grupo controle saudável (CS, n=20, 47±1 anos, 26,1±0,8 kg/m2), pareado por idade e gênero, foi também estudado. Os pacientes realizaram as seguintes avaliações: polissonografia; exames laboratoriais (glicemia, triglicérides, colesterol total e frações, leptina e proteína C-reativa); medidas antropométricas (altura, peso corporal, índice de massa corpórea, circunferência abdominal); composição corporal pela bioimpedância; medidas de pressão arterial; e TECP. Resultados. Ambos os grupos com SMet apresentaram prejuízo quando comparados ao grupo CS no peso, índice de massa corpórea e nos fatores de risco da SMet (circunferência abdominal, glicemia, triglicérides, HDL-c e pressão arterial sistólica e diastólica, P < 0,05). No TECP os grupos SMet+AOS e SMet-AOS apresentaram menores valores de consumo de oxigênio pico (VO2pico, 22,2±0,7; 21,7±0,9 e 28,0±1,1 ml/kg/min, respectivamente, Interação; P < 0,001) comparados com CS. Da mesma forma, os grupos SMet tiveram menores: VO2 no limiar anaeróbio (VO2LA), na relação VO2 e carga de trabalho (deltaVO2/deltaW) e no OUES (25,3±0,8; 25,0±0,9 e 31,1±1,2; Interação; P < 0.001) quando comparado com CS. Em análises posteriores, o OUES se correlacionou apenas com a massa gorda e com a leptina (R=-0,35; P=0,006). Conclusão. Independente da presença da AOS, pacientes com SMet apresentam diminuição da eficiência cardiorrespiratória. Os níveis elevados de leptina pode ser uma das explicações para essa diminuição nesses pacientes / Introduction. Low aerobic capacity is an important marker of poor prognosis and a strong predictor of risk of death in patients referred for cardiopulmonary exercise testing (CPET) for clinical reasons. The oxygen uptake efficiency slopes (OUES), a new cardiorespiratory efficiency index, has been used as a submaximal marker during CPET. Recent studies suggest that leptin may play an important role in regulating respiration, and consequently, increased levels of leptin may be related to decreased OUES. However, the impact of metabolic syndrome (MetS) and obstructive sleep apnea (OSA) in the OUES is unknown. Objective. To investigate the OUES in MetS patients with or without OSA. Methods. We studied 73 patients with MetS (ATP-III), allocated into two groups according to apnea/hypopnea index (AHI), assessed by nocturnal polysomnography: MetS+OSA (AHI >= 15 events/hour, n=38, 49±1 years, 33±0.6 kg/m2) and MetS-OSA (AHI < 15 events/hour, n=35, 46±1 years, 32±0.6 kg/m2). A healthy control group (CG, n=20, 47±1 years, 26.1±0.8 kg/m2), matched for age and gender, was also studied. The patients performed the following evaluations: polysomnography; Laboratory tests (glycemia, triglycerides, total cholesterol and fractions, leptin and C-reactive protein); Anthropometric measurements (height, body weight, body mass index, waist circumference); Body composition by bioimpedance; Blood pressure measurements; and CPET. Results. Both MetS groups had impairment in weight, body mass index, and MetS risk factors (waist circumference, glycemia, triglycerides, HDL-c and systolic and diastolic blood pressure, P < 0.05) compared with CG. MetS+OSA and MetS-OSA groups presented lower values of peak oxygen consumption (VO2peak, 22.2±0.7, 21.7±0.9 and 28.0±1.1 ml/kg/min, respectively; Interaction; P < 0.001) compared to CG. In the same way, MetS groups had lowest: VO2 at anaerobic threshold (VO2LA), ratio of VO2 and workload (deltaVO2/deltaW) and OUES (25.3±0.8, 25.0±0.9 and 31.1±1.2, Interaction; P < 0.001) compared with CG. In further analyzes, OUES correlated only with fat mass and leptin (R =-0.35, P =0.006). Conclusion. Regardless of the presence of OSA, MetS patients present decreased cardiorespiratory efficiency. Elevated levels of leptin may be one of the explanations for this decrease in these patients

Rates of obesity (OB) are escalating among Canadian children and youth and the obesogenic environment is likely to cause further increases. An important aspect in providing clinical care to OB children is to have accurate assessment measures, particularly of their body composition and cardiorespiratory fitness. This project entails three interrelated projects aiming to develop novel cardiorespiratory fitness and body composition measurement techniques for an OB pediatric population. The purpose of the first project was to validate a new submaximal fitness protocol specifically geared towards OB children and youth. The second objective of this thesis involved assessing cardiorespiratory efficiency utilizing the Oxygen Uptake efficiency slope. The purpose of the third project was to determine the validity of a half-body scan methodology for measuring body composition in obese children and youth. The goal of developing these novel measurement techniques is improved design and evaluation of interventions aimed at managing pediatric obesity.