Ideal cardiovascular health and inflammation in European adolescents: The HELENA study.

BACKGROUND AND AIMS: Inflammation plays a key role in atherosclerosis and this process seems to appear in childhood. The ideal cardiovascular health index (ICHI) has been inversely related to atherosclerotic plaque in adults. However, evidence regarding inflammation and ICHI in adolescents is scarce. The aim is to assess the association between ICHI and inflammation in European adolescents. METHODS AND RESULTS: As many as 543 adolescents (251 boys and 292 girls) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional multi-center study including 9 European countries, were measured. C-reactive protein (CRP), complement factors C3 and C4, leptin and white blood cell counts were used to compute an inflammatory score. Multilevel linear models and multilevel logistic regression were used to assess the association between ICHI and inflammation controlling by covariates. Higher ICHI was associated with a lower inflammatory score, as well as with several individual components, both in boys and girls (p < 0.01). In addition, adolescents with at least 4 ideal components of the ICHI had significantly lower inflammatory score and lower levels of the study biomarkers, except CRP. Finally, the multilevel logistic regression showed that for every unit increase in the ICHI, the probability of having an inflammatory profile decreased by 28.1% in girls. CONCLUSION: Results from this study suggest that a better ICHI is associated with a lower inflammatory profile already in adolescence. Improving these health behaviors, and health factors included in the ICHI, could play an important role in CVD prevention.

Influence of parental socio-economic status on diet quality of European adolescents: results from the HELENA study.

Diet quality is influenced by socio-economic and geographical factors. The present study sought to assess whether adolescents' diet quality is affected by their parents' socio-economic status and whether the relationship between these factors is similar in northern and southern Europe. Data collected in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study in eight European countries were analysed. Dietary intake data were recorded via repeated 24 h recalls (using specifically developed HELENA Dietary Intake Assessment Tool software) and converted into an adolescent-specific Diet Quality Index (DQI-AM). Socio-economic status was estimated through parental educational level (Par-Educ-Lev) and parental occupation level (Par-Occ-Lev) as reported by the adolescents in a specific questionnaire. The DQI-AM data were then analysed as a function of Par-Educ-Lev and Par-Occ-Lev in northern European countries (Austria, Belgium, France, Germany and Sweden) and southern European countries (Greece, Italy and Spain). We studied a total of 1768 adolescents (age 14.7 (SD 1.3) years; percentage of girls: 52.8%; 1135 and 633 subjects from northern and southern Europe, respectively). On average, the DQI-AM score was higher in southern Europe than in northern Europe (69.1 (SD 0.1) v. 60.4 (SD 2.8), respectively; P < 0.001; Δ = 12.6%). The DQI was positively correlated with both paternal and maternal Par-Educ-Lev. However, this association was more pronounced in northern Europe than in southern Europe (P interaction = 0.004 for the mother and 0.06 for the father). The DQI was also positively correlated with Par-Occ-Lev (all P trends < 0.01), but this correlation was independent of the geographical area (P interaction = 0.51 for the mother and 0.50 for the father). In conclusion, Par-Educ-Lev and Par-Occ-Lev are associated with diet quality in adolescents in Europe. However, this association differs between northern Europe and southern Europe.

Physical activity attenuates the negative effect of low birth weight on leptin levels in European adolescents; the HELENA study.

We examined whether physical activity (PA) influences the association between birth weight and serum leptin in adolescents. The study comprised a total of 538 adolescents (315 girls), aged 12.5-17.49 years, born at term (≥ 37 weeks of gestation). We measured serum leptin levels and time engaged in moderate-vigorous PA (MVPA) by accelerometry. There was an interaction effect between birth weight and meeting the PA recommendations (60 min/day MVPA) on leptin levels in girls (P = 0.023) but not in boys (P = 0.809). Birth weight was negatively associated with leptin levels in girls not meeting the PA recommendations (i.e. more than 60 min/day of MVPA) (ß = -0.096, P = 0.009), whereas no significant association was observed in those meeting the PA recommendations (ß = -0.061, P = 0.433). In conclusion, meeting the PA recommendations may attenuate the negative effect of low birth weight on serum leptin levels in European female adolescents.

Cardiorespiratory fitness and dietary intake in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence study.

The present study investigated the association between cardiorespiratory fitness (CRF) and dietary intake in European adolescents. The study comprised 1492 adolescents (770 females) from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. CRF was assessed by the 20 m shuttle run test. Adolescents were grouped into low and high CRF levels according to the FITNESSGRAM Standards. Dietary intake was self-registered by the adolescents using a computer-based tool for 24 h dietary recalls (HELENA-Dietary Assessment Tool) on two non-consecutive days. Weight and height were measured, and BMI was calculated. Higher CRF was associated with higher total energy intake in boys (P = 0·003). No association was found between CRF and macronutrient intake (as percentage of energy), yet some positive associations were found with daily intake of bread/cereals in boys and dairy products in both boys and girls (all P < 0·003), regardless of centre, age and BMI. CRF was inversely related to sweetened beverage consumption in girls. These findings were overall consistent when CRF was analysed according to the FITNESSGRAM categories (high/low CRF). A high CRF was not related to compliance with dietary recommendations, except for sweetened beverages in girls (P = 0·002). In conclusion, a high CRF is associated with a higher intake of dairy products and bread/cereals, and a lower consumption of sweetened beverages, regardless of centre, age and BMI. The present findings contribute to the understanding of the relationships between dietary factors and physiological health indicators such as CRF.

Short sleep duration is associated with increased obesity markers in European adolescents: effect of physical activity and dietary habits. The HELENA study.

BACKGROUND: Adequate sleep is a critical factor for adolescent's health and health-related behaviors. OBJECTIVE: (a) to describe sleep duration in European adolescents from nine countries, (b) to assess the association of short sleep duration with excess adiposity and (c) to elucidate if physical activity (PA), sedentary behaviors and/or inadequate food habits underlie this association. DESIGN: A sample of 3311 adolescents (1748 girls) aged 12.5-17.49 years from 10 European cities in Austria, Belgium, France, Germany, Greece, Hungary, Italy, Spain and Sweden was assessed in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study between 2006 and 2008. We measured anthropometric data, sleep duration, PA (accelerometers and questionnaire), television watching and food habits (Food Frequency Questionnaire). RESULTS: Average duration of daily sleep was 8 h. Shorter sleepers showed higher values of BMI, body fat, waist and hip circumferences and fat mass index (P<0.05), particularly in females. Adolescents who slept <8 h per day were more sedentary, as assessed by accelerometry, and spent more time watching TV (P<0.05). The proportion of adolescents who eat adequate amounts of fruits, vegetables and fish was lower in shorter sleepers than in adolescents who slept ≥8 h per day, and so was the probability of having adequate food habits (P<0.05). Correlation analysis indicated that short sleep is associated with higher obesity parameters. CONCLUSIONS: In European adolescents, short sleep duration is associated with higher adiposity markers, particularly in female adolescents. This association seems to be related to both sides of the energy balance equation due to a combination of increased food intake and more sedentary habits.

Harmonization process and reliability assessment of anthropometric measurements in a multicenter study in adolescents.

OBJECTIVE: To describe the standardization process and reliability of anthropometric and bioelectrical impedance analysis (BIA) measurements. We examined both intra- and interobserver errors for skinfolds, circumferences and BIA. METHODS: For the intraobserver error assessment, first of all, 202 adolescents in the pilot study (110 boys, 92 girls, aged 13.64+/-0.78 years) were assessed. For the second intraobserver and interobserver assessments, 10 adolescents were studied (5 boys and 5 girls). RESULTS: The pilot study's intraobserver technical errors of measurement (TEMs) were between 0.12 and 2.9 mm for skinfold thicknesses, and between 0.13 and 1.75 cm for circumferences. Intraobserver reliability for skinfold thicknesses was greater than 69.44% and beyond 78.43% for circumferences. The final workshop's intraobserver TEMs for skinfold thicknesses and circumferences were smaller than 1; for BIA resistance TEMs were smaller than 0.1 Omega and for reactance they were smaller than 0.2 Omega. Intraobserver reliability values were greater than 95, 97, 99 and 97% for skinfold thicknesses, circumferences, BIA resistance and reactance, respectively. Interobserver TEMs for skinfold thicknesses and circumferences ranged from 1 to 2 mm; for BIA they were 1.16 and 1.26 Omega for resistance and reactance, respectively. Interobserver reliability for skinfold thicknesses and circumferences were greater than 90%, and for BIA resistance and reactance they were greater than 90%. CONCLUSIONS: After the results of the pilot study, it was necessary to optimize the quality of the anthropometric measurements before the final survey. Significant improvements were observed in the intraobserver reliabilities for all measurements, with interobserver reliabilities being higher than 90% for most of the measurements.The Healthy Lifestyle in Europe by Nutrition in Adolescence Study aims to describe total body fat percentage and anthropometric indices of body fat distribution in European adolescents.

A feasibility study of using a diet optimization approach in a web-based computer-tailoring intervention for adolescents.

OBJECTIVE: Adolescents are an interesting but neglected target group in obesity prevention. We assessed the feasibility of using a diet optimization approach for computer-tailored nutrition interventions for adolescents. METHOD: Development of an optimization model based on the public health approach to diet optimization. On the basis of food frequency questionnaires (FFQ) of 48 adolescents (14-17 years) optimized diets were calculated. RESULTS: The optimization calculations for all cases resulted in individual advice. On a total of 137 items included in the FFQ, the individualized advice included changes in a minimum of 36 and a maximum of 88 items (mean: 61 items), recommendations for changes in the food items ranged from less than 1 g day(-1) up to 1660 g day(-1). In almost all cases a higher intake of fruit and vegetables was recommended; some unexpected advice was also generated (for example, to decrease the consumption of brown bread and to increase the consumption of pizza). The strengths and weaknesses of the optimized diets are discussed. CONCLUSION: Using the optimization approach is a step forward in nutrition tailoring interventions but the model used in the present feasibility study still needs to be refined.

Food and nutrient intake, nutritional knowledge and diet-related attitudes in European adolescents.

BACKGROUND AND OBJECTIVE: To provide an overview of methods used to assess food and nutrient intake, nutritional knowledge and diet-related attitudes in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS), with selected results from the feasibility study. MATERIAL AND METHODS: To assess food intake in 13- to 16-year-old adolescents, a previously developed computer-assisted and self-administered 24-h recall was adapted for international use. Food consumption data were linked to national food composition databases to calculate energy and nutrient intakes. To assess nutritional knowledge in pupils not having any special (trained) education concerning 'nutrition', a 23-item validated multiple choice questionnaire was adapted. To assess eating attitudes, behaviour and/or putative problems with body weight in adolescents, a validated inventory covering 60 questions or statements was adapted for the study. In a feasibility study, instruments, data collection and processing were tested in one school class in each of the 10 participating European cities. RESULTS AND CONCLUSIONS: The feasibility study provided plausible results, quite consistent between countries. Against this background and for the first time, standardized and uniform methodology was made available for the main study to assess and characterize dietary intake, nutritional knowledge and eating attitudes.

Development and evaluation of a self-administered computerized 24-h dietary recall method for adolescents in Europe.

OBJECTIVE: To describe the development of a European computerized 24-h dietary recall method for adolescents, and to investigate the feasibility of self-administration (self report) by comparison with administration by a dietician (interview). METHODS: Two hundred and thirty-six adolescents (mean age 14.6 years (s.d.=1.7)) of eight European cities completed the 24-h recall (Young Adolescents Nutrition Assessment on Computer (YANA-C)) twice (once by self-report and once by interview). RESULTS: A small but significant underestimate in energy (61 (s.e.=31) kcal) and fat (4.2 (s.e.=1.7) g) intake was found in the self-reports in comparison with the interviews; no significant differences were found for the intake of carbohydrates, proteins, fibre, calcium, iron and ascorbic acid. Spearman's correlations were highly significant for all nutrients and energy ranging between 0.86 and 0.91. Agreement in categorizing the respondents as consumers and non-consumers for the 29 food groups was high (kappa statistics >or=0.73). Percentage omissions were on average 3.7%; percentage intrusions: 2.0%. Spearman's correlations between both modes were high for all food groups, for the total sample (>or=0.76) as well as for the consumers only (>or=0.72). Analysing the consumer only, on an average 54% of the consumed amounts were exactly the same; nevertheless, only for one group 'rice and pasta' a significant difference in consumption was found. CONCLUSION: Adaptation, translation and standardization of YANA-C make it possible to assess the dietary intake of adolescents in a broad international context. In general, good agreement between the administration modes was found, the latter offering significant potential for large-scale surveys where the amount of resources to gather data is limited.

Reliability of health-related physical fitness tests in European adolescents. The HELENA Study.

OBJECTIVE: To examine the reliability of a set of health-related physical fitness tests used in the European Union-funded Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study on lifestyle and nutrition among adolescents. DESIGN: A set of physical fitness tests was performed twice in a study sample, 2 weeks apart, by the same researchers. PARTICIPANTS: A total of 123 adolescents (69 males and 54 females, aged 13.6+/-0.8 years) from 10 European cities participated in the study. MEASUREMENTS: Flexibility, muscular fitness, speed/agility and aerobic capacity were tested using the back-saver sit and reach, handgrip, standing broad jump, Bosco jumps (squat jump, counter movement jump and Abalakov jump), bent arm hang, 4 x 10 m shuttle run, and 20-m shuttle run tests. RESULTS: The ANOVA analysis showed that neither systematic bias nor sex differences were found for any of the studied tests, except for the back-saver sit and reach test, in which a borderline significant sex difference was observed (P=0.044). The Bland-Altman plots graphically showed the reliability patterns, in terms of systematic errors (bias) and random error (95% limits of agreement), of the physical fitness tests studied. The observed systematic error for all the fitness assessment tests was nearly 0. CONCLUSIONS: Neither a learning nor a fatigue effect was found for any of the physical fitness tests when repeated. The results also suggest that reliability did not differ between male and female adolescents. Collectively, it can be stated that the reliability of the set of physical fitness tests examined in this study is acceptable. The data provided contribute to a better understanding of physical fitness assessment in young people.

Increased sedentary behaviour is associated with unhealthy dietary patterns in European adolescents participating in the HELENA study.

BACKGROUND/OBJECTIVES: To assess dietary patterns (DPs) in European adolescents and to examine their relationship with several indicators of sedentary behaviour. SUBJECTS/METHODS: A multinational cross-sectional study was carried out in 2202 adolescents (45.4% boys) aged 12.5-17.5 years. A self-reported questionnaire with information on sedentary behaviours, separately for weekdays and weekend days, and two non-consecutive 24 h-recalls were used. Principal component analysis was used to obtain DPs, and linear regression examined the association between DPs scores and sedentary behaviour. RESULTS: Four DPs for boys ('plant based', 'snacking', 'breakfast' and 'health conscious') and five DPs for girls ('confectionary and snacking', 'plant based', 'breakfast', 'animal protein' and 'health conscious') were obtained. Boys who spent >4 h/day watching television (TV) had lower adherence to the 'plant based', 'breakfast' and 'health conscious' DPs, and higher adherence to the 'snacking' DP. Higher computer use and internet use for recreational reason were associated with higher adherence to the 'snacking' DP. In girls, TV viewing and using internet for recreational reasons for >4 h/day was associated with higher adherence to the 'confectionary and snacking' and lower adherence with 'health conscious' DP. Also, studying between 2 and 4 h during weekend days was associated with lower adherence to the 'snacking' and with higher adherence to the 'plant based' and 'breakfast' DPs. CONCLUSION: Adolescents' DPs are related with the time spent in several sedentary behaviours. Such findings may help to generate interventions focusing on decreasing unhealthy dietary habits and specific sedentary behaviours.

Biomarker evaluation of Greek adolescents' exposure to secondhand smoke.

Exposure to secondhand smoke (SHS) is a significant threat to public health, and represents a danger for both the development and health status of children and adolescents. Taking the above into account, our aim was to quantify Greek adolescents' exposure to SHS using serum cotinine levels. During 2006, 341 adolescents aged 13-17 were randomly selected from high schools in Heraklion and agreed to participate as part of the European Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. Blood samples were drawn from a random sample of 106 adolescents, while serum cotinine/nicotine concentrations were measured by Gas Chromatography-Mass Spectrometry (GC-MS). The mean levels of serum cotinine and nicotine were calculated at 1.60 +/- 2.18 ng/mL and 4.48 +/- 4.00 ng/mL, respectively, while 97.7% of the non-smoker adolescents were found to have measureable levels of serum cotinine indicating exposure to SHS. The analysis revealed that their paternal (p = .001) and maternal smoking habits (p = .018) as also the existence of a younger brother or sister (p = .008) were the main modifiers of SHS exposure during adolescence. Conclusively, almost all of the measured Greek adolescents were exposed to SHS, even when their parents were non-smokers. This finding indicates the need for both community and school-based educational programmes as also the implementation of a comprehensive ban on smoking in public places.