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Background: Hepatic disorders are often complex and multifactorial, modulated by genetic and environmental determinants. During the last years, the hepatic disease has been progressively established from early stages in life. The use of genetic risk scores (GRS) to predict the genetic susceptibility to a particular phenotype among youth has gained interest in recent years. Moreover, the alanine aminotransferase (ALT) blood biomarker is often considered as hepatic screening tool, in combination with imaging techniques. The aim of the present study was to develop an ALT‐specific GRS to help in the evaluation of hepatic damage risk in European adolescents. Methods: A total of 972 adolescents (51.3% females), aged 12.5–17.5 years, from the Healthy Lifestyle in Europe by Nutrition in Adolescence study were included in the analyses. The sample incorporated adolescents in all body mass index (BMI) categories and was divided considering healthy/unhealthy ALT levels, using sex‐specific cut‐off points. From 1212 a priori ALT‐related single nucleotide polymorphisms (SNPs) extracted from candidate gene selection, a first screening of 234 SNPs univariately associated was established, selecting seven significant SNPs (p <.05) in the multivariate model. An unweighted GRS (uGRS) was developed by summing the number of reference alleles, and a weighted GRS (wGRS), by multiplying each allele to its estimated coefficient. Results: The uGRS and wGRS were significantly associated with ALT (p <.001). The area under curve was obtained integrating BMI as clinical factor, improving the predictive ability for uGRS (.7039) and wGRS (.7035), using 10‐fold internal cross‐validation. Conclusions: Considering BMI status, both GRSs could contribute as complementary tools to help in the early diagnosis of hepatic damage risk in European adolescents. [ABSTRACT FROM AUTHOR]

Objectives: To examine the association of lipoprotein lipase (LPL) polymorphisms with cardiovascular disease (CVD) risk factors in European adolescents, along with the influence of physical activity on these associations. Methods: A total of 13 LPL polymorphisms were genotyped in 1.057 European adolescents (12‐18 years old) from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross‐Sectional Study. Serum lipids, glucose, insulin, and leptin (LEP) levels were measured and a CVD risk score was computed. We also measured body weight and height, waist and hip circumferences, and triceps and subscapular skinfold thickness. Physical activity was objectively measured by accelerometry for 7 days. Results: The rs1534649, rs258, rs320, and rs328 polymorphisms were associated with several CVD risk factors (ie, body mass index, triglycerides [TG], LEP, and cholesterol/high‐density lipoprotein [HDL], low‐density lipoprotein [LDL]/HDL, TG/HDL ratios). TG and TG/HDL were associated with haplotype blocks 3 (rs282, rs285 polymorphisms) and 4 (rs3126, rs320, rs328, rs10099160 polymorphisms), being the latter also associated with the CVD risk score. Physical activity modulated the association of adiposity with rs1534649 and rs258 polymorphisms. Conclusions: Polymorphisms rs1534649, rs258, rs320 and rs328, and two haplotypes of LPL were significantly associated with CVD risk factors in European adolescents. Higher levels of moderate to vigorous physical activity may attenuate the effects of rs1534649 and rs258 polymorphisms on adiposity. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the association of lifestyle patterns related to physical activity (PA), sedentariness, and sleep with endocrine, metabolic, and immunological health biomarkers in European adolescents. Methods: The present cross‐sectional study comprised 3528 adolescents (1845 girls) (12.5‐17.5 years) enrolled in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study. Cluster analysis was performed by including body composition, PA by accelerometry, self‐reported sedentary behaviors, and sleep duration. We also measured endocrine, metabolic, and immunological biomarkers. Results: Three‐cluster solutions were identified: (a) light‐PA time, moderate‐vigorous‐PA time and sedentary time, (b) light‐PA time, moderate‐vigorous‐PA time, sedentary time and sleep time, (c) light‐PA time, moderate‐vigorous‐PA time, sedentary time and body composition. In addition, each cluster solution was defined as: "healthy," "medium healthy," and "unhealthy" according to the presented rating. Analysis of variance showed that overall the healthiest groups from the three clusters analyzed presented a better metabolic profile. A decision tree analysis showed that leptin had a strong association with cluster 3 in both boys and girls, high‐density lipoprotein cholesterol had the strongest association with clusters 1 and 3 in boys. Cortisol had the strongest association with cluster 1. HOMA index (homeostatic model assessment) and C3 showed a strong association with cluster 3 in girls. Conclusions: Our results support the existence of different interactions between metabolic health and lifestyle patterns related to PA, sedentariness, and sleep, with some gender‐specific findings. These results highlight the importance to consider multiple lifestyle‐related health factors in the assessment of adolescents' health to plan favorable strategies. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess physical activity (PA) awareness of adolescents and to identify anthropometric and psychosocial factors that can lead to under or overestimation of PA. This study included 2044 adolescents. Participants wore a uniaxial accelerometer for 7 days to measure PA and completed a self-rated questionnaire about PA. Adolescents were classified into four PA awareness subgroups (realistically active, overestimators, underestimators and realistically inactive) according to the self-rated and objective assessment of PA. Characteristics and psychosocial factors of the self-rated physically active groups were compared using bivariate and multivariate mixed logistic regression models. Forty-five percent of adolescents reported their PA levels correctly (34.8% realistically active and 10.1% realistically inactive). Among the 59.4% who were objectively inactive, 82.9% tended to overestimate their PA level. Adolescents who overestimated their PA level were older (P < .05), had more support from mother and a best friend (P < .05) and had higher cardiorespiratory fitness (P < .001) compared with those who were realistically active. A significant number of adolescents believe that they are physically active when they are not. Improving awareness, especially in the high-risk groups identified here, might help to bring about behavioural changes in physically inactive adolescents. [ABSTRACT FROM PUBLISHER]

The study aims to examine the individual and combined association of early life factors (birth weight, birth length, and any and exclusive breastfeeding) with attention capacity in adolescents. The study included 421 European adolescents (243 girls), aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study. Body weight and length at birth of adolescents were collected from parental records. The duration of any and exclusive breastfeeding were self-reported. The d2 Test of Attention was administered to assess attention capacity. The main results showed that birth weight, birth length, breastfeeding, and exclusive breastfeeding were related to attention capacity in boys ( β ranging from 0.144 to 0.196; all p < .05) after adjustment for age, centre, gestational age, maternal education, family affluence scale, and body mass index. Among boys, differences in attention capacity were found according to tertiles of birth weight and birth length ( p < .05), as well as borderline significant differences across groups of any and exclusive breastfeeding ( p = 0.055 and p = 0.108, respectively) after adjusting for potential confounders. In addition, boys with 3 early life risk factors (low birth weight, low birth length, and <3 months of breastfeeding) had significantly lower scores in attention capacity compared with boys with 0 risk factors (percentile score − 15.88; p = 0.009). In conclusion, early life factors, both separately and combined, may influence attention capacity in male European adolescents. Importantly, the combination of the 3 early life risk factors, low birth weight, low birth length, and <3 months of breastfeeding, even in normal ranges, may provide the highest reduction in attention capacity. [ABSTRACT FROM AUTHOR]

Objective We studied in European adolescents (i) the association between cardiorespiratory fitness and ideal cardiovascular health as defined by the American Heart Association and (ii) whether there is a cardiorespiratory fitness threshold associated with a more favourable cardiovascular health profile. Methods Participants included 510 (n=259 girls) adolescents from 9 European countries. The 20 m shuttle run test was used to estimate cardiorespiratory fitness. Ideal cardiovascular health was defined as meeting ideal levels of the following components: four behaviours (smoking, body mass index, physical activity and diet) and three factors (total cholesterol, blood pressure and glucose). Results Higher levels of cardiorespiratory fitness were associated with a higher number of ideal cardiovascular health components in both boys and girls (both p for trend =0.001). Levels of cardiorespiratory fitness were significantly higher in adolescents meeting at least four ideal components (13% higher in boys, p<0.001; 6% higher in girls, p=0.008). Receiver operating characteristic curve analyses showed a significant discriminating accuracy of cardiorespiratory fitness in identifying the presence of at least four ideal cardiovascular health components (43.8 mL/kg/min in boys and 34.6 mL/kg/min in girls, both p<0.001). Conclusions The results suggest a hypothetical cardiorespiratory fitness level associated with a healthier cardiovascular profile in adolescents. The fitness standards could be used in schools as part of surveillance and/or screening systems to identify youth with poor health behaviours who might benefit from intervention programmes. [ABSTRACT FROM AUTHOR]

ObjectiveTo examine the association of breakfast consumption with objectively measured and self-reported physical activity, sedentary time and physical fitness.DesignThe HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Cross-Sectional Study. Breakfast consumption was assessed by two non-consecutive 24 h recalls and by a ‘Food Choices and Preferences’ questionnaire. Physical activity, sedentary time and physical fitness components (cardiorespiratory fitness, muscular fitness and speed/agility) were measured and self-reported. Socio-economic status was assessed by questionnaire.SettingTen European cities.SubjectsAdolescents (n 2148; aged 12·5–17·5 years).ResultsBreakfast consumption was not associated with measured or self-reported physical activity. However, 24 h recall breakfast consumption was related to measured sedentary time in males and females; although results were not confirmed when using other methods to assess breakfast patterns or sedentary time. Breakfast consumption was not related to muscular fitness and speed/agility in males and females. However, male breakfast consumers had higher cardiorespiratory fitness compared with occasional breakfast consumers and breakfast skippers, while no differences were observed in females. Overall, results were consistent using different methods to assess breakfast consumption or cardiorespiratory fitness (all P ≤ 0·005). In addition, both male and female breakfast skippers (assessed by 24 h recall) were less likely to have high measured cardiorespiratory fitness compared with breakfast consumers (OR = 0·33; 95 % CI 0·18, 0·59 and OR = 0·56; 95 %CI 0·32, 0·98, respectively). Results persisted across methods.ConclusionsSkipping breakfast does not seem to be related to physical activity, sedentary time or muscular fitness and speed/agility as physical fitness components in European adolescents; yet it is associated with both measured and self-reported cardiorespiratory fitness, which extends previous findings. [ABSTRACT FROM AUTHOR]

Objective: There is a substantial interest in the potential role of chocolate in the prevention of cardiovascular diseases. It has been recently reported that a higher frequency of chocolate intake is linked to lower body mass index (BMI) in adults. The aim of the present study was to determine if higher chocolate consumption also is associated with lower BMI, as well as other markers of total and central body fat, in adolescents. Methods: This study comprised 1458 adolescents (ages 12.5-17.5 y) participating in HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study). Dietary intake was self-registered using a computer-based tool for 24-h dietary recall on 2 non-consecutive days. Weight and height were measured, and BMI was calculated. Adiposity was estimated using skin-folds (Slaughter's equation) and bioelectrical impedance analysis (BIA). Waist circumference was measured. Sexual maturation also was recorded. Physical activity was measured by accelerometry. Results: Higher chocolate consumption was associated with lower levels of total and central fatness, as estimated by BMI, body fat estimated from skinfolds and BIA, and waist circumference, regardless of potential confounders (P ≤ 0.01). Conclusion: Our results demonstrate that a higher chocolate consumption was associated with lower total and central fatness in European adolescents. [ABSTRACT FROM AUTHOR]

This report aims (1) to examine the association between seasonality and physical activity (PA) and sedentary time in European adolescents and (2) to investigate whether this association was influenced by geographical location (Central-North versus South of Europe), which implies more or less extreme weather and daylight hours. Valid data on PA, sedentary time and seasonality were obtained in 2173 adolescents (1175 females; 12.5–17.5 years) included in this study. Physical activity and sedentary time were measured by accelerometers. ANCOVA was conducted to analyse the differences in PA and sedentary time across seasons. Results showed that girls had lower levels of moderate to vigorous PA (MVPA) and average PA, and spent more time in sedentary activities in winter compared with spring (allP < 0.05). Stratified analyses showed differences in PA and sedentary time between winter and spring in European girls from Central-North of Europe (P < 0.05 for sedentary time). There were no differences between PA and sedentary time across seasonality in boys. In conclusion, winter is related with less time spent in MVPA, lower average PA and higher time spent in sedentary activities in European adolescent girls, compared with spring. These differences seem to mainly occur in Central-North Europe. [ABSTRACT FROM PUBLISHER]

ObjectiveTo examine the association between breakfast consumption and CVD risk factors in European adolescents.DesignCross-sectional. Breakfast consumption was assessed by the statement ‘I often skip breakfast’ and categorized into ‘consumer’, ‘occasional consumer’ and ‘skipper’. Blood pressure, weight, height, waist circumference, skinfold thickness, total cholesterol (TC), HDL cholesterol (HDL-C), LDL cholesterol (LDL-C), TAG, insulin and glucose were measured and BMI, TC:HDL-C, LDL-C:HDL-C and homeostasis model assessment–insulin resistance index (HOMA-IR) were calculated.SettingThe European Union-funded HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.SubjectsEuropean adolescents, aged 12·50–17·49 years, from ten cities within the HELENA study (n 2929, n 925 with blood sample, 53 % females).ResultsIn males, significant differences across breakfast consumption category (‘consumer’, ‘occasional consumer’ and ‘skipper’) were seen for age, BMI, skinfold thickness, waist circumference, cardiorespiratory fitness, systolic and diastolic blood pressures, TC:HDL-C, LDL-C:HDL-C, glucose, insulin, HOMA-IR and LDL-C; in females, for cardiorespiratory fitness, skinfold thickness, BMI, insulin and HOMA-IR. In overweight/obese males significant differences were also seen for TC and LDL-C, whereas no differences were observed in non-overweight males or in females regardless of weight status.ConclusionsOur findings among European adolescents confirm previous data indicating that adolescents who regularly consume breakfast have lower body fat content. The results also show that regular breakfast consumption is associated with higher cardiorespiratory fitness in adolescents, and with a healthier cardiovascular profile, especially in males. Eating breakfast regularly may also negate somewhat the effect of excess adiposity on TC and LDL-C, especially in male adolescents. [ABSTRACT FROM AUTHOR]

Background: Although there is a growing interest in the epidemiology of sedentary behaviours, it is unknown whether sedentary behaviour questionnaires are broad markers of sedentary time. The aims of this study were to determine the: (i) reliability of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) screen time-based sedentary behaviour questionnaire; and (ii) its validity, i.e. the ability of the questionnaire to correctly rank adolescents according to the objectively measured sedentary time. Methods: A total of 183 adolescents (104 females aged 12.5–17.5 years) were involved in the reliability study. Participants completed the HELENA sedentary questionnaire twice (1 week apart). The validity study comprised 2048 (1212 females) adolescents (12.5–17.5 years of age) included in the HELENA cross-sectional study. Questions included television viewing, computer games, console games, Internet for study and non-study reasons and study during week and weekend days. We compared median values of sedentary time, using accelerometers, by tertiles of self-reported sedentary behaviours and their sum (composite sedentary score). Results: Reliability study: κ-values showed a good agreement (>0.7), except for Internet for study reasons (0.46 weekdays, 0.33 weekend). The questionnaire correctly classified boys’ sedentary time when analysed by specific behaviours and by a composite sedentary score. In girls, median values of objectively measured sedentary time were not different across tertiles of self-reported sedentary behaviours or the composite sedentary score. Conclusion: The HELENA sedentary questionnaire is reliable, yet only correctly classifies objectively measured sedentary time in boys. [ABSTRACT FROM AUTHOR]

The present study was intended to examine whether ponderal index (PI) at birth modifies the effect of the fat mass and obesity associated (FTO) rs9939609 polymorphism on adiposity in European adolescents. A total of 628 adolescents aged 14·4 (se 1·3) years (56·8 % female) were recruited. PI was calculated from parental reports of birth weight and length (kg/m3), and the BMI (kg/m2), body fat percentage and fat mass index (FMI, kg/m2) were calculated. The rs9939609 polymorphism was genotyped and physical activity assessed by accelerometry. Sex, duration of pregnancy, pubertal status, centre and physical activity were used as confounders in all the analyses. The minor A allele of the FTO rs9939609 was significantly associated with higher BMI, body fat percentage and FMI (all P < 0·05) but not with PI. Significant interactions between PI and the rs9939609 polymorphism in terms of body fat percentage (P = 0·002) and FMI (P = 0·017) were detected. However, this polymorphism was only significantly associated with higher BMI, body fat percentage and FMI (all P < 0·05) in adolescents in the lower PI tertile. Indeed, both body fat percentage and FMI were higher in those adolescents in the lower PI tertile carrying the A allele of the FTO rs9939609 polymorphism than in those with the TT genotype (25·0 (se 0·8) v. 22·1 (se 1·0) %, adjusted P = 0·030 and 5·6 (se 0·3) v. 4·6 (se 0·4) kg/m2, P = 0·031, respectively). Our findings suggest that those adolescents born with lower PI could be more vulnerable to the influence of the A risk allele of the FTO polymorphism on total adiposity content. [ABSTRACT FROM PUBLISHER]

Background: The aim of this article is to examine the association between adolescents’ physical activity (PA) levels and their relatives’ (father, mother, brothers, sisters and best friend) PA engagement and encouragement. Methods: Adolescents (52.3% girls) aged 12.5–17.5 years were gathered from the HELENA study. Adolescents’ PA levels were assessed by the International Physical Activity Questionnaire for Adolescents (valid data on 3007 participants) and accelerometry (valid data on 2200 participants). Relatives’ engagement and encouragement were reported by the adolescents and encoded into three categories (low, middle and high). Results: Analysis of covariance showed that relatives’ PA encouragement was more strongly associated with adolescents’ PA levels than relatives’ PA engagement. Pairwise comparisons indicated that the higher the encouragement level (from most relatives) the higher the adolescent’s PA levels. This finding was overall consistent when using self-report or objective methods for assessing adolescents’ PA levels, yet the associations were stronger when using self-report methods. Conclusions: These findings highlight the important role of social encouragement on adolescents’ PA levels. Community interventions aiming to enhance PA levels in the adolescent population might be more successful when family and peers are also targeted. [ABSTRACT FROM AUTHOR]

This study examined the effect of ponderal index (PI) at birth on the relationships between eight common polymorphisms of the leptin (LEP) and leptin receptor (LEPR) genes and adiposity in adolescents. A total of 823 European adolescents (45.4% girls) aged 14.8 ± 1.4 years were genotyped for the LEP (rs2167270, rs12706832, rs10244329, rs2071045, and rs3828942) and LEPR (rs1137100, rs1137101, and rs8179183) polymorphisms. The PI was calculated from parental reports of birth weight and length. Fat mass index (FMI) was calculated. Analyses were adjusted for relevant confounders. An 'adiposity-risk-allele score' based on genotypes at the three single-nucleotide polymorphisms (SNPs) associated with adolescents' FMI in adolescents within the lower tertile of PI was calculated. The LEP rs10244329 and rs3828942 polymorphisms were associated with higher FMI only in adolescents within the lower PI tertile (+0.55 kg/m2 per minor T allele, P = 0.040, and +0.58 kg/m2 per major G allele, P = 0.028, respectively). The LEPR rs8179183 polymorphism was significantly associated with higher FMI in adolescents within the lower PI tertile (+0.87 kg/m2 per minor C allele, P = 0.006). After correction for multiple comparisons, only the association between the LEPR rs8179183 and FMI persisted. However, each additional risk allele conferred 0.53 kg/m2 greater FMI in adolescents within the lower tertile of PI (P = 0.008). In conclusion, our results suggest that those adolescents born with lower PI could be more vulnerable to the influence of the LEP rs10244329 and rs3828942 polymorphisms and LEPR rs8179183 polymorphism on total adiposity content. Due to the relatively small sample size, these findings should be replicated in further larger population samples. [ABSTRACT FROM AUTHOR]

The authors’ aim in this cross-sectional study was to characterize levels of objectively measured physical activity and sedentary time in adolescents from 9 European countries. The study comprised 2,200 European adolescents (1,184 girls) participating in the HELENA cross-sectional study (2006–2008). Physical activity was measured by accelerometry and was expressed as average intensity (counts/minute) and amount of time (minutes/day) spent engaging in moderate- to vigorous-intensity physical activity (MVPA). Time spent in sedentary behaviors was also objectively measured. Cardiorespiratory fitness was measured by means of the 20-m shuttle run test. Level of maternal education was reported by the adolescents. A higher proportion of boys (56.8% of boys vs. 27.5% of girls) met the physical activity recommendations of at least 60 minutes/day of MVPA. Adolescents spent most of the registered time in sedentary behaviors (9 hours/day, or 71% of the registered time). Both average intensity and MVPA were higher in adolescents with high cardiorespiratory fitness, and sedentary time was lower in the high-fitness group. There were no physical activity or sedentary time differences between maternal education categories. These data provide an objective measure of physical activity and amount of time spent in sedentary behaviors in a relatively large number of European adolescents. [ABSTRACT FROM PUBLISHER]

Objective. To examine the independent association of total and central body fat and cardiorespiratory fitness with markers of insulin resistance after controlling for several potential confounders in European adolescents participating in the HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional) study. Methods. We conducted a cross sectional study (the HELENA-CSS) which comprised 1053 (12.5--17.5 years) adolescents from 10 European cities. Weight, height, waist circumference and skinfold thickness were measured, and body mass index (BMI) was calculated. Cardiorespiratory fitness was measured by the 20-m shuttle run test. Markers of insulin resistance were fasting insulin and glucose, and homeostasis model assessment (HOMA). Results. HOMA and insulin were positively associated with BMI, skinfolds and waist circumference after controlling for center, age, pubertal status and cardiorespiratory fitness (all P ≤≤ 0.01). HOMA and insulin were negatively associated with cardiorespiratory fitness in adolescents with moderate to high levels of total and central body fat (all P ≤≤ 0.01). Conclusions. HOMA and insulin were associated with total and central body fat in European adolescents. Moreover, cardiorespiratory fitness explained a part of the HOMA and insulin variance in those adolescents with moderate to high levels of total and central body fat, and also, to some extent, in those with low to middle fat mass. [ABSTRACT FROM AUTHOR]

The article presents a study which examined the relationship between the intensity level of physical activity (PA) and cardiorespiratory fitness (CRF) in teenagers in Europe. The data on adolescent body weight and height used in this study are extracted from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross Sectional Study (HELENA-CSS). The PA thresholds associated with a healthy CRF are assessed.

Background: It is unclear how much physical activity is necessary to prevent obesity during adolescence. Purpose: The purpose of this study was to examine whether the current physical activity guidelines for youth are associated with a lower risk of excess of body fat in European adolescents. Methods: A sample of 2094 adolescents from the HELENA cross-sectional study was selected. Levels of moderate, vigorous, and moderate to vigorous physical activity (MVPA) were assessed using accelerometers. BMI and percentage of body fat (skinfolds) were calculated and used to categorize the adolescents as normal-weight/normal-fat, overweight/overfat, and obese. Data were collected during 2006–2007. Receiver operating characteristic (ROC) analysis, performed in 2009, was used to determine thresholds that best discriminate between weight and body fat categories. Results: ROC analysis showed that ≥18 minutes/day in vigorous physical activity and ≥55 minutes/day in MVPA significantly discriminated between normal-weight and overweight+obesity categories. Moreover, ≥9 minutes/day of vigorous physical activity and ≥49 minutes/day of MVPA discriminated between normal-fat and overfat/obese adolescents. Adolescents who did not meet the current physical activity guidelines for youth of 60 minutes/day in MVPA increased the risk of having overweight+obesity (OR=1.24, 95% CI=1.01, 1.534) and overfat+obesity (OR=1.79, 95% CI=1.33, 2.42). ORs increased when adolescents did not meet the guidelines of at least 15 minutes/day in vigorous physical activity. Conclusions: Current physical activity guidelines seem to be appropriate to prevent excess of body fat in European adolescents. However, participation in vigorous physical activity might have additional importance in preventing obesity. [ABSTRACT FROM AUTHOR]

Background: The liver X receptors (LXR) α and β regulate lipid and carbohydrate homeostasis and inflammation. Lxrβ-/- mice are glucose intolerant and at the same time lean. We aimed to assess the associations between single nucleotide polymorphisms (SNPs) in LXRβ and risk of type 2 diabetes mellitus (T2DM), obesity and related traits in 3 separate cohort studies. Methods: Twenty LXRβ SNPs were identified by sequencing and genotyped in the HUNT2 adult nested case-control study for T2DM (n = 835 cases/1986 controls). Five tag-SNPs (rs17373080, rs2695121, rs56151148, rs2303044 and rs3219281), covering 99.3% of the entire common genetic variability of the LXRβ gene were identified and genotyped in the French MONICA adult study (n = 2318) and the European adolescent HELENA cross-sectional study (n = 1144). In silico and in vitro functionality studies were performed. Results: We identified suggestive or significant associations between rs17373080 and the risk of (i) T2DM in HUNT2 (OR = 0.82, p = 0.03), (ii) obesity in MONICA (OR = 1.26, p = 0.05) and (iii) overweight/obesity in HELENA (OR = 1.59, p = 0.002). An intron 4 SNP (rs28514894, a perfect proxy for rs17373080) could potentially create binding sites for hepatic nuclear factor 4 alpha (HNF4α) and nuclear factor 1 (NF1). The C allele of rs28514894 was associated with ∼1.25-fold higher human LXRβ basal promoter activity in vitro. However, no differences between alleles in terms of DNA binding and reporter gene transactivation by HNF4α or NF1 were observed. Conclusions: Our results suggest that rs17373080 in LXRβ is associated with T2DM and obesity, maybe via altered LXRβ expression. [ABSTRACT FROM AUTHOR]

Summary: Aims: To examine the association between UCP1, UCP2, and UCP3 gene polymorphisms with adiposity markers in European adolescents and to test if there were gene interactions with objectively measured physical activity and adiposity. Methods: A cross‐sectional study that involves 1.057 European adolescents (12‐18 years old) from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross‐Sectional Study. A total of 18 polymorphisms in UCP1, UCP2, and UCP3 genes were genotyped. We measured weight, height, waist, and hip circumferences and triceps and subscapular skinfold thickness. Physical activity was objectively measured by accelerometry during 7 days. Results: The C allele of the UCP1 rs6536991 polymorphism was associated with a lower risk of overweight (odds ratio [OR]: T/C + C/C vs T/T) = 0.72; 95% confidence interval [CI]: 0.53‐0.98; P = 0.034; false discovery rate [FDR] = 0.048). There was a significant interaction between UCP1 rs2071415 polymorphism and physical activity with waist‐to‐hip ratio (P = 0.006; FDR = 0.026). Adolescents who did not meet the physical activity recommendations (less than 60 min/day of moderate to vigorous physical activity) and carrying the C/C genotype had higher waist‐to‐hip ratio (+ 0.067; 95% CI, 0.028‐0.106; P = 0.003), while no differences across genotypes were observed in adolescents meeting the recommendations. Conclusions: Two UCP1 polymorphisms were associated with adiposity in European adolescents. Meeting the daily physical activity recommendations may overcome the effect of the UCP1 rs2071415 polymorphism on obesity‐related traits. [ABSTRACT FROM AUTHOR]

Background The aims of this study were to examine what amount of sedentary time is associated with low cardiorespiratory fitness (CRF) in adolescents and whether this association is independent of physical activity. Methods The study comprised 1808 adolescents aged 12.5-17.5 years from 10 European cities. Sedentary time and moderate-to-vigorous physical activity (MVPA) were measured by accelerometer. CRF was assessed by the 20 m shuttle-run test. Adolescents were divided into two groups (high/low) according to FITNESSGRAM guidelines. Receiver-operating characteristic (ROC) analysis was used to determine thresholds that best discriminate between high and low CRF in adolescents. Results Adolescent girls had more sedentary time than boys (p<0.001). ROC analysis showed that girls spending ≥69% of waking time in sedentary activities had low CRF, but no significant threshold discriminated between high and low CRF in boys. Adolescent girls who exceeded this threshold had lower levels of CRF (p≤0.001) and were more likely to have a low CRF (OR 1.68, 95% CI 1.22 to 2.31) independent of centre, age and body mass index. The negative influence of excessive sedentary time on CRF remained significant (p=0.045) in adolescent girls who did not meet the physical activity guidelines (<60 min/day in MVPA) but was abolished (p>0.05) in those who met the recommendation (≥60 min/day in MVPA). Conclusion Excessive sedentary time is associated with low CRF in adolescent girls but not in boys. However, this adverse effect might be attenuated if adolescent girls meet the current physical activity guidelines. [ABSTRACT FROM AUTHOR]

Objective: To explore the clustering of different lifestyle behaviors and whether this clustering differs by gender, age, and health-related fitness. Design: Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study. Setting: Ten European cities. Participants: A total of 2,084 adolescents (12.5-17.5 years). Main Outcome Measures: Four lifestyle behaviors were assessed by self-administered questionnaires: moderate to vigorous physical activity, homework time, screen time, and diet. Health-related fitness components (aerobic capacity, strength, speed-agility, and body composition) were assessed. Analysis: Hierarchical method and K-means cluster analysis. Analysis of variance tests. Results: Five clusters were identified: Healthy diet and Active, Healthy diet and Academic, Healthy diet and Inactive, Unhealthy diet and Screen user, and Unhealthy diet and Active. Younger adolescents were more active and followed a healthier diet than older adolescents. Older boys devoted more time to screen use, whereas older girls devoted more time to homework. Boys in the Healthy diet and Active cluster presented higher aerobic capacity and specd-agility, whereas girls presented higher aerobic capacity, strength, and speed-agility. Conclusions and Implications: Clustering of different lifestyle behaviors is observed. Different healthy lifestyles do not always come together and clusters are associated with gender, age, and health-related fitness, but not with body composition. These differences need to be considered when developing intervention strategies for the prevention of unhealthy habits. [ABSTRACT FROM AUTHOR]

Purpose: This study was aimed to analyze the mediation role of cardiorespiratory fitness (CRF) on the association between fatness and cardiometabolic risk scores (CMRs) in European adolescents., Methods: A cross-sectional study was conducted in adolescents (n = 525; 46% boys; 14.1 ± 1.1 years old, mean ± SD) from 10 European cities involved in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. CRF was measured by means of the shuttle run test, while fatness measures included body mass index (BMI), waist to height ratio, and fat mass index estimated from skinfold thicknesses. A clustered CMRs was computed by summing the standardized values of homeostasis model assessment, systolic blood pressure, triglycerides, total cholesterol/high-density lipoprotein cholesterol ratio, and leptin., Results: Linear regression models indicated that CRF acted as an important and partial mediator in the association between fatness and CMRs in 12-17-year-old adolescents (for BMI: coefficients of the indirect role β = 0.058 (95% confidence interval (95%CI): 0.023-0.101), Sobel test z = 3.11 (10.0% mediation); for waist to height ratio: β = 4.279 (95%CI: 2.242-7.059), z =3.86 (11.5% mediation); and for fat mass index: β = 0.060 (95%CI: 0.020-0.106), z = 2.85 (9.4% mediation); all p < 0.01)., Conclusion: In adolescents, the association between fatness and CMRs could be partially decreased with improvements to fitness levels; therefore, CRF contribution both in the clinical field and public health could be important to consider and promote in adolescents independently of their fatness levels., (Copyright © 2019. Production and hosting by Elsevier B.V.)

Obesity is the result of interactions between genes and environmental factors. Since monogenic etiology is only known in some obesity-related genes, a genetic risk score (GRS) could be useful to determine the genetic predisposition to obesity. Therefore, the aim of our study was to build a GRS able to predict genetic predisposition to overweight and obesity in European adolescents. A total of 1069 adolescents (51.3% female), aged 11-19 years participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study were genotyped. The sample was divided in non-overweight (non-OW) and overweight/obesity (OW/OB). From 611 single nucleotide polymorphisms (SNP) available, a first screening of 104 SNPs univariately associated with obesity (p < 0.20) was established selecting 21 significant SNPs (p < 0.05) in the multivariate model. Unweighted GRS (uGRS) was calculated by summing the number of risk alleles and weighted GRS (wGRS) by multiplying the risk alleles to each estimated coefficient. The area under curve (AUC) was calculated in uGRS (0.723) and wGRS (0.734) using tenfold internal cross-validation. Both uGRS and wGRS were significantly associated with body mass index (BMI) (p < .001). Both GRSs could potentially be considered as useful genetic tools to evaluate individual's predisposition to overweight/obesity in European adolescents.

Obesity and metabolic syndrome (MetS) are worldwide major health challenges. The Mediterranean diet (MD) is associated with a better cardiometabolic profile, but these beneficial effects may be influenced by genetic variations, modulating the predisposition to obesity or MetS. The aim was to assess whether interaction effects occur between an obesity genetic risk score (obesity-GRS) and the MD on adiposity and MetS in European adolescents. Multiple linear regression models were used to assess the interaction effects of an obesity-GRS and the MD on adiposity and MetS and its components. Interaction effects between the MD on adiposity and MetS were observed in both sex groups ( p < 0.05). However, those interaction effects were only expressed in a certain number of adolescents, when a limited number of risk alleles were present. Regarding adiposity, a total of 51.1% males and 98.7% females had lower body mass index (BMI) as a result of higher MD adherence. Concerning MetS, only 9.9% of males with higher MD adherence had lower MetS scores. However, the same effect was observed in 95.2% of females. In conclusion, obesity-related genotypes could modulate the relationship between MD adherence and adiposity and MetS in European adolescents; the interaction effect was higher in females than in males.

Objectives: Cardiovascular diseases (CVDs) are responsible of 31% of all deaths worldwide. Genetic predisposition to CVDs in adolescents remains largely unknown. Aims of present research are to examine the association of ADIPOQ gene polymorphisms with cardiovascular disease risk factors in European adolescents., Methods: A total of 14 polymorphisms in the ADIPOQ gene were genotyped in 1057 European adolescents (12-18 years old) from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study. We measured serum lipids and a CVD risk score, along with weight, height, triceps, and subscapular skinfold thickness, leptin, insulin and other markers of glucose regulation., Results: The rs822393, rs822395 and rs7649121 polymorphisms of ADIPOQ gene were significantly associated with several CVD risk factors [i.e. high-density lipoprotein cholesterol (HDL-C), apolipoprotein (Apo) A1, SBP and CVD risk score] in European adolescents. We also found an association of the TGAAGT ADIPOQ haplotype (rs822393, rs16861210, rs822395, rs822396, rs12495941 and rs7649121) with HDL-C and ApoA1 levels., Conclusion: Several individual polymorphisms (rs822393, rs822395 and rs7649121) and a haplotype of ADIPOQ gene were significantly associated with cardiovascular disease risk factors in European adolescents.

Background: Cardiovascular diseases (CVDs) are responsible for 31% of all deaths worldwide. Genetic predisposition to CVDs in adolescents remains largely unknown. The aim of this study was to examine the association of UCP1, UCP2 and UCP3 gene polymorphisms with CVD risk factors in European adolescents., Method: A cross-sectional study that involves 1.057 European adolescents (12-18 years old) from the HELENA study. A total of 18 polymorphisms of UCP1, UCP2 and UCP3 genes were genotyped. We measured serum total cholesterol, high-density lipoprotein,low-density lipoprotein, ApoA1, ApoB, leptin, triglycerides, glucose, insulin and blood pressure, and calculated HOMA (homeostatic model assessment), Quantitative Insulin Sensitivity Check Index (QUICKI) and a CVD risk score., Results: The G allele of UCP2 rs2735572 and T allele of UCP2 rs17132534 were associated with higher diastolic blood pressure (P = 0.001; false discovery rate [FDR] = 0.009 and P = 8e-04; FDR = 0.009, respectively). We observed that the AATAG haplotype of UCP1 was associated with higher serum ApoB/ApoA1 (P = 0.008; FDR = 0.031) and ApoB levels (P = 0.008; FDR = 0.031). Moreover, the ACC haplotype of UCP3 was associated with a higher CVD risk score (P = 0.0036; FDR = 0.01)., Conclusions: Two UCP2 polymorphisms and haplotypes of UCP1 and UCP3 were associated with CVD risk factors. These findings suggest that UCPs may have a role in the development of CVD already in adolescents.

Objective: To examine the association between polymorphisms of the ciliary neurotrophic factor gene (CNTF) and total and central adiposity markers in adolescents., Study Design: This cross-sectional study involved 1057 European adolescents aged 12-18 years enrolled in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study. Five polymorphisms of CNTF were genotyped, and the weight, height, waist and hip circumference, and triceps and subscapular skinfold thickness of the subjects were measured and recorded., Results: The T allele of rs2509914, the C allele of rs2515363, and the G allele of rs2515362 were significantly associated (after Bonferroni correction) with higher values for several adiposity markers under different inheritance models. The CNTF CCGGA haplotype (rs2509914, rs17489568, rs2515363 rs1800169, and rs2515362) was also significantly associated with lower body mass index, waist circumference, waist/height ratio, and waist/hip ratio values compared with the TCCGG haplotype under several inheritance models., Conclusions: Three polymorphisms-rs2509914, rs2515363, and rs2515362-and the CCGGA haplotype of CNTF were significantly associated with adiposity in European adolescents. These results suggest the potential role of CTNF in the development of obesity-related phenotypes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe., Methods: Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2-18 years) from 18 different European countries., Results: Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age., Conclusions: Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe.

Purpose: To examine the adherence to the Mediterranean dietary pattern (MDP) in metabolically healthy overweight or obese (MHO) and metabolically unhealthy obese (MUO) European adolescents., Methods: In this cross-sectional study, 137 overweight/obese adolescents aged 12-17 years old from the HELENA study were included. Height, weight, waist circumference and skinfold thickness were measured and body mass index and body fat percent were calculated. Systolic and diastolic blood pressure, glucose, HDL cholesterol, triglycerides and cardiorespiratory fitness (20 m shuttle run test) were measured. MHO and MUO phenotypes were categorized following the Jolliffe and Janssen criteria. Two non-consecutive 24 h recalls were used for dietary intake assessment and the adherence to the MDP was calculated using the Mediterranean dietary pattern score (MDP score) (range 0-9)., Results: A total of 45 (22 girls) adolescents (32.8%) were categorized as MHO. The adherence to the MDP was significantly higher in MHO than in MUO adolescents regardless of age, sex, body fat percentage, energy intake and center (MDP score: 4.6 ± 1.6 vs. 3.9 ± 1.5, p = 0.036), but this difference became non-significant after further adjustment for cardiorespiratory fitness. Participants who had a low adherence to the MDP (MDP score ≤ 4) had a higher likelihood of having MUO phenotype regardless of sex, age, energy intake, center and body fat percentage (OR 2.2; 95% CI 1.01-4.81, p = 0.048)., Conclusions: Adherence to the MDP might be beneficial to maintain metabolic health in overweight/obese adolescents, yet cardiorespiratory fitness seems to play a key role on the metabolic phenotype.

Objectives: To determine whether handgrip strength (HG) and/or standing long jump (SLJ) are capable of detecting risk of metabolic syndrome (MetS) in European adolescents, and to identify age- and sex-specific cut points for these tests., Design: Cross-sectional study., Methods: Participants included 969 (aged 12.5-17.5 years old) adolescents from 9 European countries (n = 520 girls). Absolute and relative HG and SLJ tests were used to assess upper and lower muscle strength, respectively. MetS status was determined using the age- and sex-specific cut points proposed by Jolliffe and Janssen´s, Additionally, we computed a continuous cardiometabolic risk index with the average z-score of four cardiometabolic risk factors: Wait circumference, mean arterial pressure, triglycerides/high-density lipoprotein cholesterol, and fasting insulin., Results: The prevalence of MetS was 3.1% in European adolescents. Relative HG and absolute SLJ were the best tests for detecting the presence of MetS (Area under the receiver operating characteristic (AUC) = 0.799, 95%CI:0.773-0.824; and AUC = 0.695 95%CI:0.665-0.724), respectively) and elevated cardiometabolic risk index (AUC = 0.873, 95%CI:0.838-0.902; and AUC = 0.728 95%CI:0.698-0.756), respectively) and, regardless of cardiorespiratory fitness. We provide age- and sex-specific cut points of upper and lower muscle strength for European adolescents to identify the presence of MetS and elevated cardiometabolic risk index., Conclusions: The proposed health-related cut points could be used as a starting point to define health-related levels of upper and lower muscle strength in adolescents. Likewise, the diagnostic statistics provided herein can be used to offer feedback to adolescents, parents, and education and health professionals about what it means to meet or fail test standards., (Copyright © 2019. Published by Elsevier Ltd.)

Objective: To examine the associations between adolescents' diet quality and their perceived relatives' and peers' diet engagement and encouragement., Design: Cross-sectional study performed in European countries. Diet quality was scored using the Diet Quality Index for Adolescents (DQI-A) based on four components: quality, diversity, balance and meal frequency. Perceived diet quality engagement and perceived encouragement of the relatives/peers were assessed using the questions 'How healthy is each of the following persons' diet?' and 'How often does each of the following persons encourage you to eat a healthy diet?', Setting: Vienna, Ghent, Lille, Athens, Heraklion, Pecs, Rome, Dortmund, Zaragoza and Stockholm., Subjects: Healthy adolescents (n 2943)., Results: The perceived engagement level of the mother, father and sister was each positively associated with the DQI-A (P<0·05). A positive association was found for the perceived engagement level of siblings, father and mother with all specific components (P<0·05). DQI-A was negatively associated with the perceived encouragement level from a best friend and positively associated with the encouragement level of the mother and father (P<0·05). Diversity, balance and quality components were positively associated with the perceived encouragement level from the mother and father (P<0·05), whereas the best friend's perceived encouragement was negatively associated with the meal frequency component (P<0·01)., Conclusions: These findings highlight the role of social engagement and encouragement of relatives and peers in adolescents' diet quality. Intervention or promotion programmes aimed at enhancing diet quality in adolescents should target both family and peers.

We examined the association of physical activity (PA), cardiovascular fitness (CVF) and fatness with total homocysteine (tHcy) concentrations in European adolescents. The present study comprised 713 European adolescents aged 14.8 ± 1.2 y (females 55.3%) from the multicenter HELENA cross-sectional study. PA was assessed through accelerometry, CVF by the 20-m shuttle run test, and body fat by skinfold thicknesses with the Slaughter equation. Plasma folate, cobalamin, and tHcy concentrations were measured. To examine the association of tHcy with PA, CVF, and fatness after controlling for a set of confounders including age, maturity, folate, cobalamin, creatinine, smoking, supplement use, and methylenetetrahydrofolate reductase 677 genotype (CC 47%, CT 43%, TT 10%), bivariate correlations followed by multiple regression models were performed. In the bivariate correlation analysis, tHcy concentrations were slightly negatively correlated (p<0.05) with CVF in females (measured both by stages: r=-0.118 and by VO2max: r=-0.102) and positively with body mass index (r=0.100). However, daily time spent with moderate and vigorous PA showed a weak positive association with tHcy in females (p<0.05). tHcy concentrations showed a tendency to decrease with increasing CVF and increase with increasing BMI in female European adolescents. However, tHcy concentrations were positively associated with moderate and vigorous PA in female European adolescents.

Adolescence is a critical period, because major physical and psychologic changes occur during a very short period of time. Changes in dietary habits may induce different types of nutritional disorders and are likely to track into adulthood. The aim of this review is to describe the key findings related to nutritional status in European adolescents participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. We performed a cross-sectional study in 3528 (1845 females) adolescents aged 12.5–17.5 y. Birth weight was negatively associated with abdominal fat mass in adolescents and serum leptin concentrations (in female adolescents), providing additional evidence for a programming effect of birth weight on energy homeostasis control. Breakfast consumption was associated with lower body fat content and healthier cardiovascular profile. Adolescents eat half of the recommended amount of fruit and vegetables and less than two-thirds of the recommended amount of milk and milk products but consume more meat and meat products, fats, and sweets than recommended. For beverage consumption, sugar-sweetened beverages, sweetened milk, low-fat milk, and fruit juice provided the highest amount of energy. Although the intakes of saturated fatty acids (FAs) and salt were high, the intake of polyunsaturated FAs was low. Adolescents spent, on average, 9 h/d of their waking time (66–71% and 70–73% of the registered time in boys and girls, respectively) in sedentary activities. Factors associated with adolescents’ sedentary behavior included the following: 1) age; 2) media availability in the bedroom; 3) sleeping time; 4) breakfast consumption; and 5) season. Sedentary time was also associated with cardiovascular risk factors and bone mineral content. In European adolescents, deficient concentrations were identified for plasma folate (15%), vitamin D (15%), pyridoxal 5′-phosphate (5%), β-carotene (25%), and vitamin E (5%). Scientists and public health authorities should raise awareness of the importance of a healthy and sustainable lifestyle as a foundation of the health of the European population, now and in the future.

Objective: Coordinated European projects relying on standardized methods are needed to identify health inequalities across Europe. This study aimed to compare fitness, fatness, and cardiometabolic risk between urban adolescents from the south and center-north of Europe and to explore whether physical activity (PA) and other factors might explain these differences., Methods: The Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional project comprised 3528 adolescents from the south (4 cities) and central-north (6 cities) of Europe, 1089 of whom provided blood samples for analysis. Fitness (strength, speed-agility, and cardiorespiratory fitness), total and abdominal fatness (anthropometry and bioelectrical impedance), and cardiometabolic risk (z scores including fitness, fatness, blood lipids, insulin resistance, and blood pressure) were assessed. The analyses were adjusted for socioeconomic factors, objectively measured PA (accelerometry), total energy intake and diet quality, and genetic variants of the FTO rs9939609 polymorphism., Results: Adolescents from southern Europe were less fit and fatter according to all markers (P < .001). Differences in cardiometabolic risk scores were not consistent. Adolescents from the south were less active and this would largely explain the differences observed in speed-agility and cardiorespiratory fitness. Differences in total and abdominal fatness could not be explained by PA, energy intake, diet quality, or FTO rs9939609 polymorphism., Conclusions: Fitness and fatness levels indicate that urban adolescents from the south are less healthy than those from central-northern Europe. Our data suggest that differences in PA might explain differences in important health-related fitness components, yet factors explaining the differences in fatness encountered remain unknown.

Objectives: To determine the association between the α-actinin-3 (ACTN3) R577X polymorphism and elite team-sport athletic status in three cohorts of European team-sport athletes., Design: We compared the genotype and allele frequencies of the ACTN3 R577X (rs1815739) polymorphisms between team-sport athletes (n=205), endurance athletes (n=305), sprint/power athletes (n=378), and non-athletic controls (n=568) from Poland, Russia and Spain; all participants were unrelated European men., Methods: Genomic DNA was extracted from either buccal epithelium or peripheral blood using a standard protocol. Genotyping was performed using several methods, and the results were replicated following recent recommendations for genotype-phenotype association studies., Results: Genotype distributions of all control and athletic groups met Hardy-Weinberg equilibrium (all p>0.05). Team-sport athletes were less likely to have the 577RR genotype compared to the 577XX genotype than sprint/power athletes [odds ratio: 0.58, 95% confidence interval: 0.34-0.39, p=0.045]. However, the ACTN3 R577X polymorphism was not associated with team-sports athletic status, compared to endurance athletes and non-athletic controls. Furthermore, no association was observed for any of the genotypes with respect to the level of competition (elite vs. national level)., Conclusions: The ACTN3 R577X polymorphism was not associated with team-sport athletic status, compared to endurance athletes and non-athletic controls, and the observation that the 577RR genotype is overrepresented in power/sprint athletes compared with team-sport athletes needs to be confirmed in future studies., (Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Objective: To test whether youths who engage in vigorous physical activity are more likely to have lean bodies while ingesting relatively large amounts of energy. For this purpose, we studied the associations of both physical activity and adiposity with energy intake in adolescents., Study Design: The study subjects were adolescents who participated in 1 of 2 cross-sectional studies, the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study (n = 1450; mean age, 14.6 years) or the European Youth Heart Study (EYHS; n = 321; mean age, 15.6 years). Physical activity was measured by accelerometry, and energy intake was measured by 24-hour recall. In the HELENA study, body composition was assessed by 2 or more of the following methods: skinfold thickness, bioelectrical impedance analysis, plus dual-energy X-ray absorptiometry or air-displacement plethysmography in a subsample. In the EYHS, body composition was assessed by skinfold thickness., Results: Fat mass was inversely associated with energy intake in both studies and using 4 different measurement methods (P ≤ .006). Overall, fat-free mass was positively associated with energy intake in both studies, yet the results were not consistent across measurement methods in the HELENA study. Vigorous physical activity in the HELENA study (P < .05) and moderate physical activity in the EYHS (P < .01) were positively associated with energy intake. Overall, results remained unchanged after adjustment for potential confounding factors, after mutual adjustment among the main exposures (physical activity and fat mass), and after the elimination of obese subjects, who might tend to underreport energy intake, from the analyses., Conclusion: Our data are consistent with the hypothesis that more physically active and leaner adolescents have higher energy intake than less active adolescents with larger amounts of fat mass., (Copyright © 2014 Mosby, Inc. All rights reserved.)

Objective: To assess the association between the built environment and physical fitness and physical activity in adolescents., Methods: The study included 3528 adolescents, aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. The health-related physical fitness components were assessed using the physical fitness tests. Participants wore a uniaxial accelerometer (ActiGraph®) for 7 days to measure physical activity. A specific questionnaire addressing the built environment was used. Potential confounding factors including age, gender, body mass index, body composition, pubertal status, smoking, educational level of parents, and socioeconomic status were analyzed using backward stepwise linear regression analysis., Results: Heavy traffic in the neighborhood was the strongest factor negatively associated with both physical fitness and physical activity (both P<0.05). Conversely, a secure bicycling or walking route from home to school was positively associated with various components of physical fitness and physical activity (P<0.01). Outdoor fields and gymnasiums near home were also associated with better physical fitness (P<0.01), but not with physical activity., Conclusions: A favorable built environment may contribute to health-related physical fitness and physical activity of adolescents and should be considered in future interventions and health promotion strategies., (© 2013.)

Emerging data indicate that higher levels of insulin resistance (IR) are common among children and adolescents and are related to cardiometabolic risk; therefore, IR requires consideration early in life. In addition, there is a lack of conclusive evidence regarding the role of dietary nutrients on IR. The Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) was conducted in European adolescents aged 12·5–17·5 years. A total of 637 participants with valid homeostasis model assessment (HOMA) index data and who completed at least a 2 d 24 h dietary recall were included in the study (60% of the total HELENA-CSS sample). There were two dietary indices calculated, with the only difference between them being the inclusion or not of physical activity (PA). Markers of IR such as HOMA and the quantitative insulin sensitivity check index (QUICKI) were calculated. Pubertal status, BMI and cardiorespiratory fitness (CRF) were measured as potential confounders. The dietary index including PA was inversely associated with HOMA and directly with the QUICKI in females, but not in males, after adjusting for pubertal status, centre, BMI and CRF. In conclusion, the present study indicates that considering PA as part of the dietary index is of relevance as the resulted index is inversely related to IR independently of potential confounders including CRF. Overall, these findings suggest that intervention studies aimed at preventing IR in young people should focus on increasing the quality of the diet and also on including an optimal PA level in healthy adolescents.

Objective: To analyze the association between objectively assessed physical activity (PA) and markers of insulin resistance (IR) in European adolescents and to examine whether the association of objectively assessed PA and markers of IR is modified by cardiorespiratory fitness (CRF)., Methods: A cross-sectional study at school setting was conducted in 1053 (554 girls) adolescents (12.5-17.5 yr). Weight, height, waist circumference, total body fat, PA (accelerometry), and CRF (20-m shuttle run test) were measured. Fasting insulin and glucose concentrations were measured, and homeostasis model assessment as well as quantitative insulin sensitivity check index were computed., Results: In males, vigorous PA (VPA) was negatively associated with markers of IR after adjusting for confounders including waist circumference (all p < 0.05). In females, moderate PA, moderate to vigorous PA, and average PA were negatively associated with markers of IR after adjusting for confounders (all p < 0.05). Moreover, when the sample was segmented by CRF levels all the PA intensities were significantly associated with the markers of IR in females with low CRF but not in those with middle-high CRF after adjusting for confounders., Conclusions: The findings suggest that PA is negatively associated with markers of IR after adjusting for confounders including total and central body fat in both sexes, but this relationship is modified by the CRF levels being especially important in those females with low CRF. Preventive strategies should focus not only on increasing the volume of PA but also on enhancing CRF through VPA., (© 2013 John Wiley & Sons A/S.)

Objective: To examine the association of physical activity and fitness with leptin concentrations in European adolescents, after taking into account several potential confounders including total body fat (TBF)., Study Design: We conducted a cross-sectional study in a school setting for the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study. This study included 902 (509 girls) adolescents aged 12.5-17.5 years. Weight, height, and TBF (sum of 6 skinfold thickness) were measured, and fat free mass and body mass index were calculated. Physical activity was assessed by accelerometry. Physical fitness was assessed by the handgrip, standing long jump, 4 × 10-m shuttle run, and 20-m shuttle run tests. Serum fasting leptin, insulin, and glucose concentrations were measured, and homeostasis model assessment was computed. Multiple linear regression models were used., Results: Vigorous physical activity and fitness tests (all P < .05) were negatively associated with leptin, independently of several confounders including TBF and homeostasis model assessment. These associations remained significant after further controlling for each other (physical activity and fitness)., Conclusion: These results suggest that vigorous physical activity and fitness moderate the levels of leptin concentrations, regardless of relevant confounders including TBF. Intervention programs addressed to increase high intensity physical activity and fitness as well as to assess its impact on leptin concentration are required., (Copyright © 2012 Mosby, Inc. All rights reserved.)

Objective: Atherogenesis involves an inflammatory process that occurs early in life even though clinical symptoms are not observed until adulthood. Two important protective factors for low-grade inflammation may be physical activity (PA) and fitness. We examined the independent associations of objective and subjective measurements of PA and fitness with low-grade inflammation in European adolescents., Methods: A total of 1045 adolescents, aged from 12.5 to 17.5 years old from 10 European cities, were selected from the HELENA-Cross-Sectional Study. Objectively-measured and self-reported PA variables were obtained by accelerometry and the International PA Questionnaire for Adolescents, respectively. Overall, cardiorespiratory, muscular and motor fitness variables were assessed by standardized field-based fitness tests and the International Fitness Scale. C-reactive protein (CRP), complement factors 3 (C3) and 4 (C4), interleukin-6 and TNF-α inflammatory markers were measured., Results: Objectively-measured vigorous PA was inversely associated with C3 (β=-0.094, P=0.021) but it did not remain significant after any objective fitness indicator was included in the model. Other objectively measured or self-reported assessments of PA were not significantly associated with inflammatory markers. All objective measures of fitness were inversely associated with CRP, C3 and C4, whereas only self-reported motor fitness remained significantly associated with C3, C4 and TNF-α. All these observations were independent of age, sex, city and body mass index or waist circumference., Conclusion: High PA in adolescence may play an indirect role on lessening low-grade inflammation through improvements in fitness., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Aim: The aim of this study was to test the hypothesis that a lower birth weight, as an indicator of adverse intrauterine environment, is associated with higher serum leptin levels in European adolescents. We also examined the possible sexual dimorphism in this relationship., Methods: Fasting serum leptin was measured in 757 European born at term adolescents (429 females) aged 14.6 ± 1.2 yr. We measured weight and height, and body mass index was calculated. Birth weight, duration of pregnancy, and duration of breast-feeding were obtained from parental records. Duration of pregnancy and breast-feeding, pubertal status, center, body mass index, and physical activity were entered as confounders in the analyses., Results: There was a significant interaction effect between sex and birth weight on serum leptin levels (P = 0.044). We observed that body weight at birth was negatively and significantly associated with serum leptin levels only in female adolescents (β = -0.109; adjusted P = 0.008). The association persisted after further controlling for physical activity (β = -0.115; adjusted P = 0.016)., Conclusions: These findings provide further evidence for a sex-specific programming effect of birth weight on serum leptin levels. Our results also contribute to explain the detrimental health effects associated with lower birth weight, such as long-term increased risk of developing obesity and type 2 diabetes.

Objectives: Nutritional factors in early life may have long-term physiologic effects in humans. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) play important roles in protecting against cardiovascular disease (CVD) risk. Our aim was to examine the association of birth weight (BW) with serum long chain polyunsaturated fatty acids (LCPUFA) profile in adolescents., Subjects and Methods: A total of 772 European adolescents (56.3% females) aged 14.7 ± 1.2 years were included in this study. Information on BW and gestational age was obtained from parental records. DHA, EPA and arachidonic acid (AA) concentrations were measured in serum phospholipids. Alfa-linolenic (ALA), linoleic (LA), AA, EPA and DHA intakes assessed by a computer based 24h dietary recall. Gender, gestational age, pubertal status, body mass index, center and total energy and LCPUFA intakes were used as confounders in all the analyses., Results: BW was significantly associated with serum DHA and EPA (both adjusted P<0.05) independently of potential confounders including their main dietetic source. We did not observe any significant relationship between BW and serum AA levels., Conclusions: Our findings suggest that early metabolic changes, as a result from prenatal environmental influences, could affect long chain polyunsaturated fatty acid metabolism later in life. These results may contribute to explain the relationship between early nutrition and growth and later metabolic disorders as CVD., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

The purpose was to compare data obtained from a modified, long, self-administered version of the International Physical Activity Questionnaire (IPAQ-A) with objective data obtained in parallel from Actigraph accelerometers, and VO(2)max in adolescents. The study comprised a total of 2018 adolescents (46% male) from ten European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Physical activity was assessed over seven consecutive days by accelerometry and expressed as min/day of moderate, vigorous, and moderate to vigorous (MVPA) physical activity (PA). PA was also assessed with the IPAQ-A. VO(2)max was estimated from a 20-m shuttle run test. Poor to fair correlations between the two methodologies were found for the whole study sample and when stratified by age and gender (r(s) = 0.08-0.26, p < 0.01). On average, the self-reported time spent in moderate PA was higher compared to the time measured with the accelerometer, while the differences between both instruments were less clear for vigorous intensity. Adolescents reporting high levels of PA (3rd tertile IPAQ-A) also showed higher levels of PA (accelerometers) in all the study variables (moderate, vigorous and MVPA), compared to adolescents reporting low PA (1st tertile IPAQ-A) (all p < 0.001). Both methods were moderately correlated with estimated VO(2)max. Within the HELENA-study, the IPAQ-A showed the modest comparability with the accelerometer data for assessing PA in each intensity level and was the highest for vigorous intensity. Both instruments are able to detect the adolescents with the highest cardio respiratory fitness, which are the most active adolescents., (Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.)

Objective: The goal of the present study was to assess the relationship between the genetic variability in six genes of methyl group (CH(3)) metabolism and the risk of obesity., Methods: Single nucleotide polymorphisms (SNP) were selected among the methylene-tetrahydrofolate reductase (MTHFR), methionine synthase (MTR), methionine synthase reductase (MTRR), cystationine betha-syntase (CBS), transcobalamin-II (TCN2) and paraoxonase-1 (PON1) genes. The associations between SNPs and the risk of obesity were assessed in a case-control study of obese and normal-weight adolescents (age: 14.9±1.2 years), and the relationship between SNPs and body fat markers (i.e., body mass index [BMI], percentage body fat [BF%] and waist circumference [WC]) in a cross-sectional study of 1 155 European adolescents (age: 14.8±1.4 years). Genotyping was performed on an Illumina system and plasma folate level was determined by immunoassay., Results: In the case-control study, there was no evidence for any association between SNPs of MTHFR, MTR, CBS, TCN2 and PON1 and obesity (all p values ≥0.08). In contrast, two SNPs of MTRR were associated with a higher (rs10520873, Odds Ratio: 1.68 [1.18-2.39]; p=0.004) or lower (rs1801394, 0.61 [0.42-0.87]; p=0.007) risk of obesity. In the cross-sectional sample, rs1801394 was associated with lower BMI (p=0.03) and lower waist circumference (p=0.02). However, after Bonferroni correction these associations were no longer significant. No other significant association or interaction between folate levels and SNPs were detected for anthropometric variables., Conclusion: Our findings do not support an association between MTHFR, MTR, CBS, TCN2 and PON1 SNPs and obesity in adolescence. Further investigations are necessary to confirm the possible association between the rs1801394 variant of MTRR and obesity.

Purpose: The present study investigates the effect of the Activ-O-Meter, an internet-based computer-tailored physical activity intervention in adolescents in six European centers involved in the HELENA study., Methods: Adolescents (12-17 years old) from Vienna, Ghent, Heraklion, Dortmund, Athens, and Stockholm were randomized into intervention and control schools. Participants in the intervention condition received the computer-tailored advice at baseline and after 1 month. Participants in the control condition received a generic standard advice. Effects were evaluated after 1 (n = 675) and 3 months (n = 494) using multi-level modeling. Physical activity levels were measured using the International Physical Activity Questionnaire for adolescents (IPAQ-A)., Results: After 1 month, the intervention group reported higher levels of moderate (beta = -32.8, 95% CI (confidence interval): -64.2 to -1.4) and vigorous (beta = -28.0, 95% CI: -50.7 to -5.3) physical activity in leisure time, as well as higher levels of cycling for transport (beta = -19.1, 95% CI: -34.4 to -7.6) compared to the control group. After 3 months, when the intervention group had received the tailored feedback twice, intervention effects were even stronger. Favorable changes in physical activity levels of all intensities and in different contexts were found in the tailored group compared to the control group. Among adolescents not reaching the physical activity recommendations at baseline similar effects as in the total sample were found., Conclusions: The data indicated that the computer-tailored physical activity intervention had positive effects on physical activity levels among the adolescents. However, the implementation of the computer-tailored intervention in the schools was not feasible in all countries., (Copyright 2010 Society for Adolescent Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To examine the association between anthropometric measurements of total and central adiposity and blood pressure in school-aged children, and to study whether these associations are modified by the levels of cardiorespiratory fitness., Methods: Systolic and diastolic blood pressure, weight, height, skinfold thickness and waist circumference were measured in 873 children aged 9-10 years participating in the Estonian and Swedish part of the European Youth Heart Study. Mean arterial pressure was calculated. Body mass index and skinfold thickness were used as markers of total adiposity, whereas waist circumference and waist-height ratio were used as markers of central adiposity. Cardiorespiratory fitness was estimated by a maximal ergometer bike test, and dichotomized into low and high levels., Results: Markers of total and central adiposity were positively associated with blood pressure. The results from the regression models showed that the markers of total and central adiposity were significantly associated with systolic blood pressure in girls with low levels of cardiorespiratory fitness. Similar results were observed when mean arterial pressure was the outcome variable. None of the markers of total and central adiposity were significantly associated with blood pressure in girls with high levels of cardiorespiratory fitness or in boys with low or high levels of cardiorespiratory fitness., Conclusions: The results show a positive influence of simple anthropometric measurements of total and central adiposity on blood pressure, and suggest that higher cardiorespiratory fitness may attenuate the association between body fat and blood pressure in school-aged children.