Independent associations between physical activity and aerobic fitness with metabolic risk factors in children: The European Youth Heart Study

Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, South Denmark, Denmark
Diabetologia (Impact Factor: 6.67). 10/2007; 50(9):1832-40. DOI: 10.1007/s00125-007-0762-5
Source: PubMed


High levels of cardiorespiratory fitness (CRF) and physical activity (PA) are associated with a favourable metabolic risk profile. However, there has been no thorough exploration of the independent contributions of cardiorespiratory fitness and subcomponents of activity (total PA, time spent sedentary, and time spent in light, moderate and vigorous intensity PA) to metabolic risk factors in children and the relative importance of these factors.
We performed a population-based, cross-sectional study in 9- to 10- and 15- to 16-year-old boys and girls from three regions of Europe (n = 1709). We examined the independent associations of subcomponents of PA and CRF with metabolic risk factors (waist circumference, BP, fasting glucose, insulin, triacylglycerol and HDL-cholesterol levels). Clustered metabolic risk was expressed as a continuously distributed score calculated as the average of the standardised values of the six subcomponents.
CRF (standardised beta = -0.09, 95% CI -0.12, -0.06), total PA (standardised beta = -0.08, 95% CI -0.10, -0.05) and all other subcomponents of PA were significantly associated with clustered metabolic risk. After excluding waist circumference from the summary score and further adjustment for waist circumference as a confounding factor, the magnitude of the association between CRF and clustered metabolic risk was attenuated (standardised beta = -0.05, 95% CI -0.08, -0.02), whereas the association with total PA was unchanged (standardised beta = -0.08 95% CI -0.10, -0.05).
PA and CRF are separately and independently associated with individual and clustered metabolic risk factors in children. The association between CRF and clustered risk is partly mediated or confounded by adiposity, whereas the association between activity and clustered risk is independent of adiposity. Our results suggest that fitness and activity affect metabolic risk through different pathways.

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    • "Studies show that children who are physically active are more likely to maintain an active lifestyle through their adulthood (Raitakan et al. 1994). Moreover, being active during childhood was found to decrease several health risk factors, such as obesity (Parsons et al. 1999; Raitakan et al. 1994), metabolic syndrome (Brage et al. 2004; Ekelund et al. 2006), and clustering of risk factors for cardiovascular diseases (Ekelund et al. 2007). Although walking and bicycling often suffer from a negative image (Underwood et al 2014), they are considered to be two types of physical activity that are the easiest to adopt and adhere to. "
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    ABSTRACT: Previous studies examined environmental correlates of children’s physical activity. While most of these studies used aggregated physical activity measures (i.e., overall physical activity, active travel), little is known about the contribution of specific environmental attributes to specific types of physical activity. This study examined associations between GIS-based environmental measures and children’s selfreported walking and bicycling. The study area included “traditional neighborhoods” (N=4), characterized by high-density, land-use mix and grid-street network, and “suburban neighborhoods” (N=3), characterized by low-density, land-use segregation, and cul-de-sac streets. Data on children’s physical activity and psychosocial and socio-demographic factors were obtained through a school survey (of fifth and sixth graders) (N=573). Urban-form measures (intersection density, residential density, and built coverage) were significantly positively associated with walking and negatively associated with bicycling. These associations remained significant after controlling for social, intra- and inter-personal factors. These findings suggest that certain environments may encourage children’s walking and hinder their bicycling at the same time (and vice versa) and therefore raise the need for a more clear distinction between child-related walkability and bikeablilty.
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    • "These shortcomings result in substantial misclassification, and comparison between studies using different criteria is difficult. When children are analysed, there is also a major difference between the number of children diagnosed with MetS compared to the number where a clustering of risk factors occurs [11] [12]. "
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    ABSTRACT: The aim of the study was to test the performance of a new definition of metabolic syndrome (MetS), which better describes metabolic dysfunction in children. Methods. 15,794 youths aged 6-18 years participated. Mean z-score for CVD risk factors was calculated. Sensitivity analyses were performed to evaluate which parameters best described the metabolic dysfunction by analysing the score against independent variables not included in the score. Results. More youth had clustering of CVD risk factors (>6.2%) compared to the number selected by existing MetS definitions (International Diabetes Federation (IDF) < 1%). Waist circumference and BMI were interchangeable, but using insulin resistance homeostasis model assessment (HOMA) instead of fasting glucose increased the score. The continuous MetS score was increased when cardiorespiratory fitness (CRF) and leptin were included. A mean z-score of 0.40-0.85 indicated borderline and above 0.85 indicated clustering of risk factors. A noninvasive risk score based on adiposity and CRF showed sensitivity and specificity of 0.85 and an area under the curve of 0.92 against IDF definition of MetS. Conclusions. Diagnosis for MetS in youth can be improved by using continuous variables for risk factors and by including CRF and leptin.
    Full-text · Article · May 2015 · Journal of Diabetes Research
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    • "Several studies concluded that low levels of PA and high levels of SB have been associated with increased overall cardio-metabolic risk [10] [11] [12] [13] and overweight [14] [15] among children. Some of them have analyzed the associations between PA and single cardiovascular diseases risk factors [13] [14] [16], and have shown that these associations are often very weak. "
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    ABSTRACT: Background/Objective: Increased physical activity (PA) and decreased sedentary behaviors (SB) may have beneficial effects on cardio-metabolic risk in adolescents. The aim of this study was to examine the associations between independent/combined effects of PA and SB with individual/clustered cardio-metabolic risk factors. Methods: A sample of 769 adolescents (12.5-17.5 years) from the HELENA cross-sectional study (Healthy Lifestyle in Europe by Nutrition in Adolescence) and with valid data on metabolic risk factors were included. Results: Concerning moderate-to-vigorous-PA (MVPA) and vigorous-PA (VPA), measured with accelerometers, girls tended to do more MVPA (36%) and VPA (114%) than boys. Unadjusted analyses show a positive association between “PA≥60min/d; SB≥2h” and the ratio TC/HDL-c (β= 0.27; 95%CI 0.01 to 0.52; p<0.05), and a negative association between “MVPA≥60min/d; SB<2h” with the ∑4Skinfolds (β=-0.32; 95%CI -0.61 to -0.02; p<0.05). Moreover, “SB≥2h/d” was associated with increased cardio-metabolic risk (PR 1.59; 95%CI 1.05 to 2.39; p<0.05), while “PA≥60min/d; SB<2h” had a protective effect against cardio-metabolic risk (PR 0.48; 95%CI 0.25 to 0.91; p<0.05). After adjustment for potential confounders, a positive association between SB and ∑4Skinfolds was shown (β= 0.28; 95%CI 0.04 to 0.53; p<0.05). Furthermore, VO2max (mL/Kg/min) tend to increase in those participants who do higher VPA and less SB (p=0.042), and there was a protective effect of “VPA≥30min/d; SB<2h” against cardio-metabolic risk (PR 0.24; 95%CI 0.07 to 0.85; p<0.05). Conclusion: The current study suggests that adolescents should be encouraged to decrease sedentary lifestyle and increase physical activity, especially vigorous physical activity, in order to reduce cardio-metabolic risk.
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