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Research considering physical activity (PA), physical inactivity and health outcomes among urban and rural youth has produced equivocal findings. This study examined PA, physical inactivity, sedentary behaviours and cardiorespiratory fitness (CRF) in adolescents from urban and rural communities in the Portuguese Midlands. The sample included 362 adolescents (165 males, 197 females) of 13–16 years of age. CRF was assessed by the PACER test. A GT1M accelerometer was used to record 5 consecutive days of PA and time spent sedentary. Analyses of covariance (chronological age as co-variate) were performed to test the effect of the area of residence on sedentary behaviour, PA and CRF. Urban youth of both sexes spent less time in sedentary activities than rural youth. Urban males were more active than rural peers at the weekend, whereas urban females were significantly less active than rural females on week days and across all days assessed. Rural youth of both sexes had higher levels of CRF than urban youth. Area of residence was related to aerobic fitness, PA and time spent in sedentary behaviours among Portuguese youth. Interventions seeking to enhance health and active lifestyles in Portuguese youth should consider the potential impact of socio-geographic factors. [ABSTRACT FROM AUTHOR]

OBJECTIVE -- We examined the independent relationships between objectively measured physical activity and insulin resistance in Portuguese children. RESEARCH DESIGN AND METHODS -- This is a school-based, cross-sectional study in 147 randomly selected girls (aged 9.8 0.3 years; 27.8 9.3% body fat) and 161 boys (aged 9.8 0.3 years; 22,0 9.2% body fat). Physical activity was assessed by the Actigraph accelerometer for 4 days and summarized as time spent sedentary (accelerometer counts <500/min), in light-intensity (accelerometer counts 500-2,000/min), and in moderate- and vigorous-intensity activity (accelerometer counts >2,001/min). We measured total and central fat mass by dual-energy X-ray absorptiometry. Insulin resistance was expressed as the homeostasis model assessment score. RESULTS -- Time (min/day) spent sedentary was significantly and positively associated with insulin resistance (β-coefficient = 0.001 [95% CI 0.0002-0.002]; P = 0.013). Time spent in moderate- and vigorous-intensity physical activity (-0.002 [-0.003 to -0.001]; P = 0.0009) and overall physical activity (-0.001 [-0.008 to 0.003]; P < 0.0001) were significantly and inversely associated with insulin resistance. All associations remained statistically significant, although they were attenuated after further adjustments for sex, birth weight, sexual maturity, and total or central fat mass (P < 0.03). CONCLUSIONS -- Physical activity is associated with insulin resistance independent of total and central tat mass in children. Our results emphasize the importance of decreasing sedentary behavior and increasing time spent in moderate- and vigorous-intensity activity in children, which may have beneficial effects on metabolic risk factors regardless of the degree of adiposity. [ABSTRACT FROM AUTHOR]

Background. Levels of overweight have increased and fitness has decreased in children. Potentially, these changes may be a threat to future health. Numerous studies have measured changes in body mass index (BMI), but few have assessed the independent effects of low fitness, overweight and physical inactivity on cardiovascular (CVD) risk factors. Methods. A cross-sectional multi-center study including 1 769 children from Denmark, Estonia and Portugal. The main outcome was clustering of CVD risk factors. Independent variables were waist circumference, skinfolds, physical activity and cardio-respiratory fitness. Results. Both waist circumference and skinfolds were associated with clustered CVD risk. Odds ratios for clustered CVD risk for the upper quartiles compared with the lowest quartile were 9.13 (95% CI: 5.78-14.43) and 11.62 (95% CI: 7.11-18.99) when systolic blood pressure, triglyceride, insulin resistance homeostasis assessment model (HOMA) score, cholesterol:HDL, and fitness were included in the score. When fitness was removed from the clustered risk variable, the association for fatness attenuated and after further adjustment for fitness, only the highest quartiles of the fatness parameters were significant. Fitness showed the same strength of association with the clustered risk score including systolic blood pressure, triglyceride, HOMA score, and cholesterol:HDL with odds ratio for the upper quartile of 4.97 (95% CI: 3.20-7.73). Physical activity was associated with clustered risk even after adjustment for fitness and fatness with an odds ratio for the upper quartile of 1.81 (95% CI: 1.18-2.76). Conclusion. Physical activity, fitness, skinfold and waist circumference were all independently associated with clustered CVD risk. [ABSTRACT FROM AUTHOR]

Objectives To examine the association between socioeconomic position and insulin resistance in children from three countries in northern Europe (Denmark), eastern Europe (Estonia), and southern Europe (Portugal) that have different physical, economic, and cultural environments. Design Cross sectional study. Participants 3189 randomly selected schoolchildren aged 9 and 15 years from Denmark (n = 933), Estonia (n = 1103), and Portugal (n = 1153). Main outcome measure Insulin resistance (homeostasis model assessment). Results Family income and parental education were inversely associated with insulin resistance in Danish children but were positively associated with insulin resistance in Estonian and Portuguese children. Among Danish children, insulin resistance was 24% lower (95% confidence interval -38% to -10%) in those whose fathers had the most education compared with those with the least education. The equivalent results were 15% (2% to 28%) higher for Estonia and 19% (2% to 36%) higher for Portugal. These associations remained after adjustment for a range of covariates: -20% (-36% to -5%) for Denmark, 10% (-4% to 24%) for Estonia, and 18% (-1% to 31%) for Portugal. Strong statistical evidence supported differences between the associations in Denmark and those in the other two countries in both unadjusted and adjusted models (all P < 0.03). Conclusions Among Danish children, those with the most educated and highest earning parents had least insulin resistance, whereas the opposite was true for children from Estonia and Portugal. [ABSTRACT FROM AUTHOR]

Background and Design: Few studies have investigated the association between maximal cardiorespiratory capacity (fitness) and the clustered cardiovascular disease (CVD) risk in children and youth from culturally diverse countries. This cross-sectional study examined the association between fitness and clustered CVD risk in children and adolescents from three European countries., Methods: Participants were 2845 randomly selected school children aged 9 or 15 years from Portugal (n=944), Denmark (n=849) and Estonia (n=1052). Cardiorespiratory fitness was determined during a maximal test on a cycle ergometer. CVD risk factors selected to assess the degree of clustering were the total cholesterol/high-density lipoprotein cholesterol ratio, plasma triglycerides, insulin resistance (homeostasis model assessment), sum of four skinfolds, and systolic blood pressure., Results: There was a strong association between cardiorespiratory fitness and the clustering of CVD risk factors. The odds ratios for clustering in each quartile of fitness, using the quartile with the highest fitness as reference, were 13.0 [95% confidence interval (CI) 8.8-19.1]; 4.8 (95% CI 3.2-7.1) and 2.5 (95% CI 1.6-3.8), respectively, after adjusting for country, age, sex, socio-economic status, pubertal stage, family history of CVD and diabetes. In stratified analyses by age group, sex and country, similar strong patterns were observed., Conclusion: Low cardiorespiratory fitness is strongly associated with the clustering of CVD risk factors in children independent of country, age and sex.

Background: TV viewing has been linked to metabolic-risk factors in youth. However, it is unclear whether this association is independent of physical activity (PA) and obesity., Methods and Findings: We did a population-based, cross-sectional study in 9- to 10-y-old and 15- to 16-y-old boys and girls from three regions in Europe (n = 1,921). We examined the independent associations between TV viewing, PA measured by accelerometry, and metabolic-risk factors (body fatness, blood pressure, fasting triglycerides, inverted high-density lipoprotein (HDL) cholesterol, glucose, and insulin levels). Clustered metabolic risk was expressed as a continuously distributed score calculated as the average of the standardized values of the six subcomponents. There was a positive association between TV viewing and adiposity (p = 0.021). However, after adjustment for PA, gender, age group, study location, sexual maturity, smoking status, birth weight, and parental socio-economic status, the association of TV viewing with clustered metabolic risk was no longer significant (p = 0.053). PA was independently and inversely associated with systolic and diastolic blood pressure, fasting glucose, insulin (all p < 0.01), and triglycerides (p = 0.02). PA was also significantly and inversely associated with the clustered risk score (p < 0.0001), independently of obesity and other confounding factors., Conclusions: TV viewing and PA may be separate entities and differently associated with adiposity and metabolic risk. The association between TV viewing and clustered metabolic risk is mediated by adiposity, whereas PA is associated with individual and clustered metabolic-risk indicators independently of obesity. Thus, preventive action against metabolic risk in children may need to target TV viewing and PA separately.

Objectives: To examine the association between socioeconomic position and insulin resistance in children from three countries in northern Europe (Denmark), eastern Europe (Estonia), and southern Europe (Portugal) that have different physical, economic, and cultural environments., Design: Cross sectional study., Participants: 3189 randomly selected schoolchildren aged 9 and 15 years from Denmark (n = 933), Estonia (n = 1103), and Portugal (n = 1153)., Main Outcome Measure: Insulin resistance (homoeostasis model assessment)., Results: Family income and parental education were inversely associated with insulin resistance in Danish children but were positively associated with insulin resistance in Estonian and Portuguese children. Among Danish children, insulin resistance was 24% lower (95% confidence interval -38% to -10%) in those whose fathers had the most education compared with those with the least education. The equivalent results were 15% (2% to 28%) higher for Estonia and 19% (2% to 36%) higher for Portugal. These associations remained after adjustment for a range of covariates: -20% (-36% to -5%) for Denmark, 10% (-4% to 24%) for Estonia, and 18% (-1% to 31%) for Portugal. Strong statistical evidence supported differences between the associations in Denmark and those in the other two countries in both unadjusted and adjusted models (all P < 0.03)., Conclusions: Among Danish children, those with the most educated and highest earning parents had least insulin resistance, whereas the opposite was true for children from Estonia and Portugal.

Background: The rising prevalence of obesity in children may be due to a reduction in physical activity (PA)., Objective: Our aim was to study the associations of objectively measured PA volume and its subcomponents with indicators of body fatness., Design: A cross-sectional study of 1292 children aged 9-10 y from 4 distinct regions in Europe (Odense, Denmark; the island of Madeira, Portugal; Oslo; and Tartu, Estonia) was conducted. PA was measured by accelerometry, and indicators of body fatness were the sum of 5 skinfold thicknesses and body mass index (BMI; in kg/m(2)). We examined the associations between PA and body fatness by using general linear models adjusted for potential confounding variables., Results: After adjustment for sex, study location, sexual maturity, birth weight, and parental BMI, time (min/d) spent at moderate and vigorous PA (P = 0.032) and time (min/d) spent at vigorous PA were significantly (P = 0.015) and independently associated with body fatness. Sex, study location, sexual maturity, birth weight, and parental BMI explained 29% (adjusted R(2) = 0.29) of the variation in body fatness. Time spent at vigorous PA explained an additional 0.5%. Children who accumulated <1 h of moderate PA/d were significantly fatter than were those who accumulated >2 h/d., Conclusions: The accumulated amount of time spent at moderate and vigorous PA is related to body fatness in children, but this relation is weak; the explained variance was <1%.