[Show abstract][Hide abstract] ABSTRACT: Since stress is hypothesized to play a role in the etiology of obesity during adolescence, research on associations between adolescent stress and obesity-related parameters and behaviours is essential. Due to lack of a well-established recent stress checklist for use in European adolescents, the study investigated the reliability and validity of the Adolescent Stress Questionnaire (ASQ) for assessing perceived stress in European adolescents.
The ASQ was translated into the languages of the participating cities (Ghent, Stockholm, Vienna, Zaragoza, Pecs and Athens) and was implemented within the HELENA cross-sectional study. A total of 1140 European adolescents provided a valid ASQ, comprising 10 component scales, used for internal reliability (Cronbach α) and construct validity (confirmatory factor analysis or CFA). Contributions of socio-demographic (gender, age, pubertal stage, socio-economic status) characteristics to the ASQ score variances were investigated. Two-hundred adolescents also provided valid saliva samples for cortisol analysis to compare with the ASQ scores (criterion validity). Test-retest reliability was investigated using two ASQ assessments from 37 adolescents.
Cronbach α-values of the ASQ scales (0.57 to 0.88) demonstrated a moderate internal reliability of the ASQ, and intraclass correlation coefficients (0.45 to 0.84) established an insufficient test-retest reliability of the ASQ. The adolescents' gender (girls had higher stress scores than boys) and pubertal stage (those in a post-pubertal development had higher stress scores than others) significantly contributed to the variance in ASQ scores, while their age and socio-economic status did not. CFA results showed that the original scale construct fitted moderately with the data in our European adolescent population. Only in boys, four out of 10 ASQ scale scores were a significant positive predictor for baseline wake-up salivary cortisol, suggesting a rather poor criterion validity of the ASQ, especially in girls.
In our European adolescent sample, the ASQ had an acceptable internal reliability and construct validity and the adolescents' gender and pubertal stage systematically contributed to the ASQ variance, but its test-retest reliability and criterion validity were rather poor. Overall, the utility of the ASQ for assessing perceived stress in adolescents across Europe is uncertain and some aspects require further examination.
BMC Public Health 09/2011; 11:717. · 2.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Since stress is hypothesized to be involved in the aetiology of obesity, the present study examined the current perception of stress in European adolescents and the association between adolescent perceived stress and their adiposity.
Observational data from 1121 adolescents aged 12.5-17.5 years from six European cities involved in the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional study, was investigated. The adolescents completed the adolescent stress questionnaire, comprising 10 different stress dimensions. Anthropometric measurements (weight, height, skinfold thicknesses and circumferences) and bioelectrical impedance analysis were performed, and personal characteristics (age, pubertal stage and parental education) were collected. The measures of perceived stress were described for boys and girls separately and gender differences were investigated. Associations between the adolescents' perceived stress and indicators of general (body mass index z-score, sum of skinfold thicknesses and body fat%) and abdominal (waist and hip circumference, and waist/height ratio) adiposity were examined using hierarchical linear models.
While girls reported systematically higher levels of stress compared with boys, their stress profiles were similar, with highest levels for school-related stress followed by future uncertainty. Only in girls, perceived stress was significantly associated with increased measures of general and abdominal adiposity. In boys, no relationship between perceived stress and adiposity measures was observed.
School is reported to be an important source of adolescent stress and should be the focus of stress management campaigns. Only in girls, the hypothesis that stress might be involved in the aetiology of obesity during adolescence was supported.
The European Journal of Public Health 09/2011; 22(4):519-24. · 2.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To increase knowledge about reliability and intermethods agreement for body fat (BF) is of interest for assessment, interpretation, and comparison purposes. It was aimed to examine intra- and inter-rater reliability, interday variability, and degree of agreement for BF using air-displacement plethysmography (Bod-Pod), dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and skinfold measurements in European adolescents. Fifty-four adolescents (25 females) from Zaragoza and 30 (14 females) from Stockholm, aged 13-17 years participated in this study. Two trained raters in each center assessed BF with Bod-Pod, DXA, BIA, and anthropometry (DXA only in Zaragoza). Intermethod agreement and reliability were studied using a 4-way ANOVA for the same rater on the first day and two additional measurements on a second day, one each rater. Technical error of measurement (TEM) and percentage coefficient of reliability (%R) were also reported. No significant intrarater, inter-rater, or interday effect was observed for %BF for any method in either of the cities. In Zaragoza, %BF was significantly different when measured by Bod-Pod and BIA in comparison with anthropometry and DXA (all P < 0.001). The same result was observed in Stockholm (P < 0.001), except that DXA was not measured. Bod-Pod, DXA, BIA, and anthropometry are reliable for %BF repeated assessment within the same day by the same or different raters or in consecutive days by the same rater. Bod-Pod showed close agreement with BIA as did DXA with anthropometry; however, Bod-Pod and BIA presented higher values of %BF than anthropometry and DXA.
[Show abstract][Hide abstract] ABSTRACT: Plasma-borne angiopoietin-like proteins (ANGPTL) act as endocrine factors on their target tissues. Because ANGPTL3 and ANGPTL4 play important roles in lipid metabolism and the regulation of adiposity in mice, we hypothesized that genetic variability at the ANGPTL3 and ANGPTL4 genes loci might influence lipid metabolism and fat deposition in humans.
The aim of the study was to examine the association between ANGPTL3 and ANGPTL4 genetic polymorphisms and metabolic phenotypes in adolescent and adult samples.
Two independent population-based studies, one composed of 1144 adolescents (mean age, 14.8 +/- 1.4 yr) from nine European countries (the HELENA study) and the other composed of 1155 adults (age range, 35-65 yr) from Northern France (the MONICA Lille study), were genotyped for one ANGPTL3 polymorphism and four ANGPTL4 polymorphisms.
The ANGPTL3 rs11207997 polymorphism (minor allele frequency, 0.32) was associated with lower plasma HDL-cholesterol and apolipoprotein A-I levels in both adolescents (P = 0.0004, P = 0.00006, respectively) and adults (P = 0.03, P = 0.02, respectively). The ANGPTL4 rs4076317 polymorphism (minor allele frequency, 0.29) was associated with a higher percentage of body fat (P = 0.02) in adolescents and a higher waist-to-hip ratio (in interaction with the peroxisome proliferator-activated receptor gamma Pro12Ala polymorphism) in adults (P = 0.0004).
The present study underlines the role of ANGPTL3 in HDL-cholesterol metabolism as early as in adolescence. Our data also suggest possible associations between ANGPTL4 polymorphisms and body fat, but these findings require replication.
The Journal of Clinical Endocrinology and Metabolism 11/2009; 94(12):5070-7. · 6.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
A set of physical fitness tests was performed twice in a study sample, 2 weeks apart, by the same researchers.
A total of 123 adolescents (69 males and 54 females, aged 13.6+/-0.8 years) from 10 European cities participated in the study.
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.
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.
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.
International journal of obesity (2005) 12/2008; 32 Suppl 5:S49-57. · 5.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
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).
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%.
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.
International journal of obesity (2005) 12/2008; 32 Suppl 5:S58-65. · 5.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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).
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).
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.
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.
International journal of obesity (2005) 11/2008; 32 Suppl 5:S26-34. · 5.22 Impact Factor