Sigmund A. Anderssen

Physical activity and clustered cardiovascular risk in children: a cross-sectional study (The European Youth Heart Study)

BACKGROUND Atherosclerosis develops from early childhood; physical activity could positively affect this process. This studys aim was to assess the associations of objectively measured physical activity with clustering of cardiovascular disease risk factors in children and derive guidelines on the basis of this analysis. METHODS We did a cross-sectional study of 1732 randomly selected 9-year-old and 15-year-old school children from Denmark, Estonia, and Portugal. Risk factors included in the composite risk factor score (mean of Z scores) were systolic blood pressure, triglyceride, total cholesterol/HDL ratio, insulin resistance, sum of four skinfolds, and aerobic fitness. Individuals with a risk score above 1 SD of the composite variable were defined as being at risk. Physical activity was assessed by accelerometry. FINDINGS Odds ratios for having clustered risk for ascending quintiles of physical activity (counts per min; cpm) were 3.29 (95% CI 1.96-5.52), 3.13 (1.87-5.25), 2.51 (1.47-4.26), and 2.03 (1.18-3.50), respectively, compared with the most active quintile. The first to the third quintile of physical activity had a raised risk in all analyses. The mean time spent above 2000 cpm in the fourth quintile was 116 min per day in 9-year-old and 88 min per day in 15-year-old children. INTERPRETATION Physical activity levels should be higher than the current international guidelines of at least 1 h per day of physical activity of at least moderate intensity to prevent clustering of cardiovascular disease risk factors.

TV viewing and physical activity are independently associated with metabolic risk in children: the European Youth Heart Study.

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.

Independent associations of physical activity and cardiorespiratory fitness with metabolic risk factors in children: the European youth heart study

Aims/hypothesisHigh 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.MethodsWe 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.ResultsCRF (standardised β = −0.09, 95% CI −0.12, −0.06), total PA (standardised β = −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 β = −0.05, 95% CI −0.08, −0.02), whereas the association with total PA was unchanged (standardised β = −0.08 95% CI −0.10, −0.05).Conclusions/interpretationPA 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.

Low cardiorespiratory fitness is a strong predictor for clustering of cardiovascular disease risk factors in children independent of country, age and sex.

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.

A century of trends in adult human height

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3–19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8–144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries. DOI: http://dx.doi.org/10.7554/eLife.13410.001

Fitness, fatness and clustering of cardiovascular risk factors in children from Denmark, Estonia and Portugal: the European Youth Heart Study.

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.

Comparison of self-reported versus accelerometer-measured physical activity.

INTRODUCTION The International Physical Activity Questionnaire (IPAQ) is one of the most widely used questionnaires to assess physical activity (PA). Validation studies for the IPAQ have been executed, but still there is a need for studies comparing absolute values between IPAQ and accelerometer in large population studies. PURPOSE To compare PA and sedentary time from the self-administered, short version of the IPAQ with data from ActiGraph accelerometer in a large national sample. METHODS A total of 1751 adults (19-84 yr) wore an accelerometer (ActiGraph GT1M) for seven consecutive days and completed the IPAQ-Short Form. Sedentary time, total PA, and time spent in moderate to vigorous activity were compared in relation to sex, age, and education. RESULTS Men and women reported, on average, 131 min·d (SE = 4 min·d) less sedentary time compared with the accelerometer measurements. The difference between self-reported and measured sedentary time and vigorous-intensity PA was greatest among men with a lower education level and for men 65 yr and older. Although men reported 47% more moderate to vigorous physical activity (MVPA) compared with women, there were no differences between sexes in accelerometer-determined MVPA. Accelerometer-determined moderate PA was reduced from 110 to 42 min·d (62%) when analyzed in blocks of 10 min (P < 0.0001) compared with 1-min blocks. The main correlation coefficients between self-reported variables and accelerometer measures of physical activity were between 0.20 and 0.46. CONCLUSIONS The participants report through IPAQ-Short Form more vigorous PA and less sedentary time compared with the accelerometer. The difference between self-reported and accelerometer-measured MVPA increased with higher activity and intensity levels. Associations between the methods were affected by sex, age, and education, but not body mass index.

Accelerometer-Determined Physical Activity in Adults and Older People

PURPOSE There is a lack of large-scale comparable data on the population levels of physical activity (PA) and sedentary activity. We conducted a cross-sectional population-based multicenter study to describe the levels of PA and sedentary activity and to determine adherence to current national PA recommendations in Norwegian adults and older people. METHODS In 2008 and 2009, PA was assessed objectively for seven consecutive days using the ActiGraph GT1M accelerometer in 3867 participants age 20-85 yr. A total of 3267 participants provided valid PA assessments that met all inclusion criteria. RESULTS Women and men did not differ in the overall activity levels (335 and 342 counts per minute, respectively) or in steps per day (8113 and 7951 steps per day, respectively). However, for intensity-specific PA, men accumulated significantly more minutes of sedentary activity and moderate-to-vigorous PA (MVPA) compared with women (557 vs 533 min of sedentary activity, P ≤ 0.001 and 35 vs 33 min of MVPA, P = 0.01). Both overall activity levels and steps per day remained steady with age, until 65 yr, after which activity levels declined. CONCLUSIONS Overall, the study sample spent 62% of their time being sedentary, 25% in low-intensity PA, 9% in lifestyle activity, and 4% in MVPA. One in five people met current national PA recommendations. These results suggest that adults and older people spend the majority of their time being sedentary and that adherence to PA recommendations is low.

Validity of physical activity monitors in adults participating in free-living activities

Background For a given subject, time in moderate to very vigorous intensity physical activity (MVPA) varies substantially among physical activity monitors. Objective In the present study, the primary objective, whether time in MVPA recorded with SenseWear Pro2 Armband (Armband; BodyMedia, Pittsburgh, Pennsylvania, USA), ActiGraph (7164, LLC, Fort Walton Beach, Florida, USA), ikcal (Teltronic AG, Biberist, Switzerland) and ActiReg (PreMed AS, Oslo, Norway) is different compared with indirect calorimetry, was determined. The secondary objective, whether these activity monitors estimate energy expenditure differently compared with indirect calorimetry, was also determined. Material and methods The activity monitors and a portable oxygen analyser were worn by 14 men and 6 women for 120 min doing a variety of activities of different intensities. Resting metabolic rate was measured with indirect calorimetry. The cutoff points defining moderate, vigorous and very vigorous intensity were three, six and nine times resting metabolic rate. Results Time in MVPA was overestimated by 2.9% and 2.5% by Armband and ActiGraph, respectively, and was underestimated by 11.6% and 98.7% by ikcal and ActiReg, respectively. ActiReg (p = 0.004) and ActiGraph (p = 0.007) underestimated energy expenditure in MVPA, and all monitors underestimated total energy expenditure (by 5% to 21%). Conclusions Recorded time in MVPA and energy expenditure varies substantially among physical activity monitors. Thus, when comparing physical activity level among studies, it is essential to know the type of physical activity monitor being used.

Prevalence and correlates of the metabolic syndrome in a population-based sample of European youth.

BACKGROUND Until recently, there has been no unified definition of the metabolic syndrome (MetS) in the youth. Therefore, the prevalence of MetS and its association with potential correlates are largely unknown. OBJECTIVE The objective was to quantify the prevalence, identify the correlates, and examine the independent associations between potential correlates with MetS. DESIGN A population-based cohort study was conducted in 10- and 15-y-old youth from Estonia, Denmark, and Portugal (n = 3193). MetS was defined according to the International Diabetes Federation. Correlates included maternal socioeconomic status, body mass index (BMI), hypertension, and prevalent diabetes and maternally reported childs birth weight and duration of breastfeeding. Data on sexual maturity, objectively measured physical activity, cardiorespiratory fitness, self-reported sports participation, television viewing, and regular play were collected for the children. RESULTS The prevalence of MetS was 0.2% and 1.4% in 10- and 15-y-olds, respectively. Cardiorespiratory fitness (standardized odds ratio: 0.33; 95% CI: 0.15, 0.75), physical activity (standardized odds ratio: 0.40; 95% CI: 0.18, 0.88), and maternal BMI (standardized odds ratio: 1.61; 95% CI: 1.11, 2.34) were all independently associated with MetS after adjustment for sex, age group, study location, birth weight, and sexual maturity. An increase in daily moderate-intensity physical activity by 10-20% was associated with a 33% lower risk of being categorized with MetS. CONCLUSIONS High maternal BMI and low levels of cardiorespiratory fitness and physical activity independently contribute to the MetS and may be targets for future interventions. Relatively small increases in physical activity may significantly reduce the risk of MetS in healthy children.