RESUMO
The specific role of different strength measures on mortality risk needs to be clarified to gain a better understanding of the clinical importance of different muscle groups, as well as to inform intervention protocols in relation to reducing early mortality. The aim of the systematic review and meta-analysis was to determine the relationship between muscular strength and risk of cancer mortality. Eligible cohort studies were those that examined the association between muscular strength, as assessed using validated tests, and cancer mortality in healthy youth and adults. The hazard ratio (HR) estimates obtained were pooled using random effects meta-analysis models. The outcome was cancer mortality assessed using the HR (Cox proportional hazards model). Eleven prospective studies with 1 309 413 participants were included, and 9787 cancer-specific deaths were reported. Overall, greater handgrip (HR = 0.97, 95% CI, 0.92-1.02; P = .055; I2 = 18.9%) and knee extension strength (HR = 0.98, 95% CI, 0.95-1.00; P = .051; I2 = 60.6%) were barely significant associated with reduced risk of cancer mortality. Our study suggests that higher level of muscular strength is not statistically associated with lower risk of cancer mortality.
Assuntos
Força da Mão , Neoplasias/mortalidade , Humanos , Modelos de Riscos ProporcionaisRESUMO
BACKGROUND: The scientific interest in high-intensity interval training (HIIT) has greatly increased during recent years. OBJECTIVE: The objective of this meta-analysis was to determine the effectiveness of HIIT interventions on cardio-metabolic risk factors and aerobic capacity in overweight and obese youth, in comparison with other forms of exercise. DATA SOURCES: A computerized search was made using seven databases. STUDY ELIGIBILITY CRITERIA: The analysis was restricted to studies that examined the effect of HIIT interventions on cardio-metabolic and/or aerobic capacity in pediatric obesity (6-17 years old). PARTICIPANTS AND INTERVENTIONS: Nine studies using HIIT interventions were selected (n = 274). STUDY APPRAISAL AND SYNTHESIS METHODS: Standarized mean difference (SMD) and 95% confidence intervals were calculated. The DerSimonian-Laird approach was used. RESULTS: HIIT interventions (4-12 week duration) produced larger decreases in systolic blood pressure (SMD = 0.39; -3.63 mmHg) and greater increases in maximum oxygen uptake (SMD = 0.59; 1.92 ml/kg/min) than other forms of exercise. Also, type of comparison exercise group and duration of study were moderators. CONCLUSIONS: HIIT could be considered a more effective and time-efficient intervention for improving blood pressure and aerobic capacity levels in obese youth in comparison to other types of exercise. © 2016 World Obesity.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Treinamento Intervalado de Alta Intensidade , Síndrome Metabólica/prevenção & controle , Sobrepeso/terapia , Obesidade Infantil/terapia , Adolescente , Criança , Tolerância ao Exercício , Humanos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
OBJECTIVE: Arterial stiffness is a contributor to the development of atherosclerosis and cardiovascular disease. The aim of the study was to analyse the relationship between sedentary behaviour and arterial stiffness in a Spanish adult population. METHODS: This cross-sectional study included 1365 subjects belonging to the EVIDENT project. Physical activity and sedentary behaviour were measured objectively over 7 days using ActiGraph accelerometers. Thresholds of 10 consecutive minutes were used to estimate the daily sedentary time in bouts ≥10 min. Each interruption in sedentary time (counts/min ≥100) was considered a break. Arterial stiffness was evaluated using the B-pro device through the following indicators: radial Augmentation Index (rAIx), Ambulatory Arterial Stiffness Index (AASI), and central and peripheral pulse pressure (PP). RESULTS: We found a positive relationship between central and peripheral pulse pressure (office, 24 h, awake and sleep PP) and total sedentary time. These arterial stiffness parameters were also associated with sedentary time in bouts ≥10 min. Significance disappeared in both cases, however, after adjusting for MVPA and breaks per sedentary hour. Adults who reported fewer breaks per sedentary hour (25th percentile < 2 n/day) had higher levels of AASI, awake and sleep PP. CONCLUSIONS: In a medium-sized sample of adult attenders of community clinics our data showed that it seems to be important to avoid prolonged uninterrupted periods of sedentary time.