Identification of lifestyle risk factors in adolescence influencing cardiovascular health in young adults: the BELINDA study

Cardiovascular diseases are the leading cause of mortality worldwide. These diseases originate in childhood, and a better understanding of their early determinants and risk factors would allow better prevention. The BELINDA (BEtter LIfe by Nutrition During Adulthood) study is a 10–14-year follow-up of the HEalthy Lifestyle in Europe by Nutrition in Adolescence study (the HELENA study, a European cross-sectional study in adolescents). The study aims to evaluate cardiovascular risk using the PDAY (Pathobiological Determinants of Atherosclerosis in Youth) risk score during young adulthood (21–32 years), and to examine the impact of risk factors identified during adolescence (12.5–17.5 years). Our secondary objective is to compare the characteristics of the BELINDA study population with the HELENA population not participating in the follow-up study. The HELENA study recruited 3528 adolescents during 2006–2007 and reassessed 232 of them 10–14 years later as young adults. We assessed clinical status, anthropometry, nutrition, physical activity (including sedentary behavior), physical fitness, and mental health parameters, and collected biological samples (blood, stool, and hair). Dietary intake, and physical activity and fitness data were also collected. A multivariable linear regression model will be used for the analysis of the primary outcome. A Chi-square and T-test were conducted for the comparison of the descriptive data (gender, age, weight, height, body mass index (BMI), and maternal school level) between participating and non-participating BELINDA adolescents. When comparing the 1327 eligible subjects with the 232 included in the BELINDA study, no significant differences regarding gender (p = 0.72), age (p = 0.60), height (p = 0.11), and weight (p = 0.083) at adolescence were found. However, the participating population had a lower BMI (20.4 ± 3.1 kg/m2 versus 21.2 ± 3.6 kg/m2; p < 0.001) and a higher maternal educational level (46.8% high school or university level versus 38.6%; p = 0.027) than the HELENA population who did not participate in the BELINDA study. The complete phenotyping obtained at adolescence through the HELENA study is a unique opportunity to identify adolescent risk factors for cardiovascular diseases. This paper will serve as a methodological basis for future analysis of this study

Comparison of uniaxial and triaxial accelerometry in the assessment of physical activity among adolescents under free-living conditions: the HELENA study

<p>Abstract</p> <p>Background</p> <p>Different types of devices are available and the choice about which to use depends on various factors: cost, physical characteristics, performance, and the validity and intra- and interinstrument reliability. Given the large number of studies that have used uniaxial or triaxial devices, it is of interest to know whether the different devices give similar information about PA levels and patterns. The aim of this study was to compare physical activity (PA) levels and patterns obtained simultaneously by triaxial accelerometry and uniaxial accelerometry in adolescents in free-living conditions.</p> <p>Methods</p> <p>Sixty-two participants, aged 13-16 years, were recruited in this ancillary study, which is a part of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA). All participants wore a uniaxial accelerometer (ActiGraph GT1M^®, Pensacola, FL) and a triaxial accelerometer (RT3^®, Stayhealthy, Monrovia, CA) simultaneously for 7 days. The patterns were calculated by converting accelerometer data output as a percentage of time spent at sedentary, light, moderate, and vigorous PA per day. Analysis of output data from the two accelerometers were assessed by two different tests: Equivalence Test and Bland & Altman method.</p> <p>Results</p> <p>The concordance correlation coefficient between the data from the triaxial accelerometer and uniaxial accelerometer at each intensity level was superior to 0.95. The ANOVA test showed a significant difference for the first three lower intensities while no significant difference was found for vigorous intensity. The difference between data obtained with the triaxial accelerometer and the uniaxial monitor never exceeded 2.1% and decreased as PA level increased. The Bland & Altman method showed good agreement between data obtained between the both accelerometers (<it>p </it>< 0.05).</p> <p>Conclusions</p> <p>Uniaxial and triaxial accelerometers do not differ in their measurement of PA in population studies, and either could be used in such studies.</p

El estatus socioeconómico influencia la condición física en adolescentes europeos : el estudio HELENA

Introduction: The influence of socioeconomic status on health-related fitness is not clear. Aim: To examine the influence of socioeconomic status on health-related fitness in adolescents. Methods: A total of 3,259 adolescents (15.0 ± 1.3 y) from the Healthy Lifestyle in Europe by Nutrition in Ado- lescence Cross-Sectional Study (HELENA-CSS) partici- pated in the study. Socioeconomic status was assessed by the family affluence scale (FAS). Speed-agility, muscular strength and cardiorespiratory fitness were assessed. Covariates included total body fat, physical activity and pubertal status. Results: Adolescents with high FAS had significantly higher fitness levels than their peers of lower FAS cate- gories except for speed-agility and handgrip in boys. Overall, the associations observed presented a medium to large effect size. Conclusion: These results suggest that socioeconomic status is positively associated with physical fitness in European adolescents independently of total body fat and habitual physical activityIntroducción: La influencia del estatus socioeconómico sobre la condición física en relación con la salud no está clara. Objetivo: Examinar la influencia del estatus socioeconómico sobre la condición física en relación con la salud en adolescentes. Metodología: Un total de 3259 adolescentes (15,0 ± 1,3 años) del “Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study” (HELENA-CSS) participaron en el estudio. El estatus socioeconómico fue medido con una escala de riqueza familiar “family affluence scale (FAS)”. Se midieron velocidad-agilidad, fuerza muscular y capacidad aeróbica. Las covariables incluidas fueron grasa corporal total, actividad física y estadio madurativo. Resultados: Los adolescentes con alto FAS tuvieron significativamente mayores niveles de condición física que aquellos con bajo FAS exceptuando los tests de velocidad-agilidad y fuerza de prensión manual en chicos. En general, las asociaciones observadas presentaron un efecto del tamaño de la muestra (effect size) entre medio y largo. Conclusión: Estos resultados sugieren que el estatus socioeconómico esta positivamente asociado con la condición física en adolescentes Europeos independientemente de la grasa corporal total y el nivel de actividad física

Food portion sizes and their relationship with energy, and nutrient intakes in adolescents: The HELENA study

Objectives This study aimed to investigate the associations between portion sizes (PSs) from different food groups and energy, as well as nutrient intakes in European adolescents. Methods A sample of 1631 adolescents (54.2 % girls) were included from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional (HELENA) study. Mean food PS was calculated by dividing the total intake of the items by the number of eating occasions of these consumed items. To determine the key items for analysis, foods were ranked by frequency of consumption. A one-way between-groups analysis of covariance was used to test for significant differences in means across tertiles. A multivariable linear regression analysis was carried out, adjusting for age, sex, maternal education, body mass index, and using country as a level. Results Energy intake increased with elevated intakes of energy-dense foods. Large portions of rice and other grains, starch roots and potatoes, and meat substitutes, nuts, and pulses were associated with increased carbohydrate and fiber intake. Larger portions of cheese and butter and animal fat were significantly associated with a higher fat intake. Lower intakes of some vitamins and micronutrients were noticed with consumption of larger portions of high energy-dense foods, such as desserts and pudding, margarine and vegetable oil, and butter and animal fat. Conclusions Large food PSs may be associated with positive energy, as well as macro- and micronutrient intake. Moreover, the findings from this study may help the future development of dietary guidance in general and specific to PSs, and support targeted strategies to address intakes of certain nutrients in European adolescents

Socioeconomic questionnaire and clinical assessment in the HELENA Cross-sectional Study: methodology

Rationale: Environmental factors such as dietary habits, breastfeeding, socioeconomic conditions and educational factors are strong influences on nutritional and puberty status, physical activity, food choices and their interactions. Several diseases of adulthood seem to be linked to, or to originate from, lifestyle in childhood and adolescence. Objective: The aims of this study are to describe birth parameters and socioeconomic factors and to assess clinical status in adolescents aged 13-16 years from 10 European countries participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Cross-Sectional Study (CSS). Methodology: A self-report questionnaire on the socioeconomic status, a parental questionnaire concerning neonatal period and also a case report form (CRF), in which clinical items during clinical examination (such as medical history, treatments, anthropometry, Tanner staging, blood pressure, heart rate) were assessed. To develop these documents, first a list of items was established, a search of existing documents was performed and the advice of local and international experts was taken. All documents (questionnaires and an operations manual) were discussed in plenary HELENA meetings; a final version of these documents was fixed, and the process of translation and back translation was performed. Results: The questionnaires and CRF were tested for validation in all 10 participant cities; 208 adolescents were enrolled during the pilot study. All items that caused problems or questions in one or more participating centers or were completed by < 85% of the adolescents were reviewed before the beginning of the HELENA-CSS. Conclusion: These final questionnaires and CRF will contribute to better understanding of the inequalities in nutrition, behavior and health in the European adolescent population. The experience and process should be useful for other multicenter studies

Adsorption dynamics of hydrophobically modified polymers at an air-water interface

The adsorption dynamics of a series of hydrophobically modified polymers, PAAαCn, at the air-water interface is studied by measuring the dynamic surface tension. The PAAαCn are composed of a poly(acrylic acid) backbone grafted with a percentage α of C8 or C12 alkyl moieties, at pH conditions where the PAA backbone is not charged. The observed adsorption dynamics is very slow and follows a logarithmic behavior at long times indicating the building of an energy barrier which grows over time. After comparison of our experimental results to models from the literature, a new model which accounts for both the deformation of the incoming polymer coils as well as the deformation of the adsorbed pseudo-brush is described. This model enables to fit very well the experimental data. The two fitting parameters give expected values for the monomer size and for the area per adsorbed polymer chain.This article is uploaded in "arXiv.org" https://arxiv.org/abs/1706.0710

Influence of sex, age, pubertal maturation and body mass index on circulating white blood cell counts in healthy European adolescents—the HELENA study

Percentiles 10th, 25th, 50th, 75th and 90th are presented for circulating white blood cells (WBC), neutrophils, lymphocytes, monocytes, eosinophils and basophils in healthy European adolescents (12.5–17.5 years, n = 405, 48.9 % boys), considering age, sex, puberty and body mass index (BMI). CD3+ (mature T cells), CD4+ (T helper), CD8+ (T cytotoxic), CD16+56+ (natural killer), CD19+ (B cells), CD3+CD45RA+, CD4+CD45RA+, CD8+CD45RA+ (naïve), CD3+CD45RO+, CD4+CD45RO+ and CD8+CD45RO+ (memory) lymphocytes were also analysed by immunophenotyping. Girls presented higher WBC, neutrophil, CD3+CD45RO+ and CD4+CD45RO+ cell counts and CD3+/CD19+ ratio, and lower CD3+CD45RA+ and CD4+CD45RA+ counts than boys. Age was associated with higher neutrophil counts and CD3+/CD19+, and lower CD19+ counts; in boys, with lower CD3+CD45RA+, CD4+CD45RA+ and CD8+CD45RA+ counts as well; in girls, with higher WBC, CD3+CD45RO+ and CD4+CD45RO+ counts. Pubertal maturation in boys was associated with lower WBC and lymphocyte counts; in girls, with higher basophil, CD3+CD45RO+ and CD4+CD45RO+ values. BMI was associated with higher WBC counts; in boys, also with higher lymphocyte counts; in girls, with higher neutrophil, CD4+, CD3+CD45RO+ and CD4+CD45RO+ counts. Conclusion: Our study provides normative values for circulating immune cells in adolescents, highlighting the importance of considering sex, age, pubertal maturation and BMI when establishing reference ranges for WBC in paediatric populations

Food portion sizes and their relationship with energy, and nutrient intakes in adolescents: The HELENA study

[Objectives] This study aimed to investigate the associations between portion sizes (PSs) from different food groups and energy, as well as nutrient intakes in European adolescents.[Methods] A sample of 1631 adolescents (54.2 % girls) were included from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional (HELENA) study. Mean food PS was calculated by dividing the total intake of the items by the number of eating occasions of these consumed items. To determine the key items for analysis, foods were ranked by frequency of consumption. A one-way between-groups analysis of covariance was used to test for significant differences in means across tertiles. A multivariable linear regression analysis was carried out, adjusting for age, sex, maternal education, body mass index, and using country as a level.[Results] Energy intake increased with elevated intakes of energy-dense foods. Large portions of rice and other grains, starch roots and potatoes, and meat substitutes, nuts, and pulses were associated with increased carbohydrate and fiber intake. Larger portions of cheese and butter and animal fat were significantly associated with a higher fat intake. Lower intakes of some vitamins and micronutrients were noticed with consumption of larger portions of high energy-dense foods, such as desserts and pudding, margarine and vegetable oil, and butter and animal fat.[Conclusions] Large food PSs may be associated with positive energy, as well as macro- and micronutrient intake. Moreover, the findings from this study may help the future development of dietary guidance in general and specific to PSs, and support targeted strategies to address intakes of certain nutrients in European adolescents.Peer reviewe

Relationship between self-reported dietary intake and physical activity levels among adolescents: The HELENA study

Background Evidence suggests possible synergetic effects of multiple lifestyle behaviors on health risks like obesity and other health outcomes. Therefore it is important to investigate associations between dietary and physical activity behavior, the two most important lifestyle behaviors influencing our energy balance and body composition. The objective of the present study is to describe the relationship between energy, nutrient and food intake and the physical activity level among a large group of European adolescents. Methods The study comprised a total of 2176 adolescents (46.2% male) from ten European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Dietary intake and physical activity were assessed using validated 24-h dietary recalls and self-reported questionnaires respectively. Analyses of covariance (ANCOVA) were used to compare the energy and nutrient intake and the food consumption between groups of adolescents with different physical activity levels (1st to 3rd tertile). Results In both sexes no differences were found in energy intake between the levels of physical activity. The most active males showed a higher intake of polysaccharides, protein, water and vitamin C and a lower intake of saccharides compared to less active males. Females with the highest physical activity level consumed more polysaccharides compared to their least active peers. Male and female adolescents with the highest physical activity levels, consumed more fruit and milk products and less cheese compared to the least active adolescents. The most active males showed higher intakes of vegetables and meat, fish, eggs, meat substitutes and vegetarian products compared to the least active ones. The least active males reported the highest consumption of grain products and potatoes. Within the female group, significantly lower intakes of bread and cereal products and spreads were found for those reporting to spend most time in moderate to vigorous physical activity. The consumption of foods from the remaining food groups, did not differ between the physical activity levels in both sexes. Conclusion It can be concluded that dietary habits diverge between adolescents with different self-reported physical activity levels. For some food groups a difference in intake could be found, which were reflected in differences in some nutrient intakes. It can also be concluded that physically active adolescents are not always inclined to eat healthier diets than their less active peers.The HELENA study took place with the financial support of the European Community Sixth RTD Framework Programme (Contract FOOD-CT: 2005-007034). This work was also partially supported by the European Union, in the framework of the Public Health Programme (ALPHA project, Ref: 2006120), the Swedish Council for Working Life and Social Research (FAS), the Spanish Ministry of Education (EX-2007-1124, and EX-2008-0641), and the Spanish Ministry of Health, Maternal, Child Health and Development Network (number RD08/0072) (JPRL, LAM)

Evaluation of iron status in European adolescents through biochemical iron indicators: the HELENA Study

BACKGROUND/OBJECTIVES: To assess the iron status among European adolescents through selected biochemical parameters in a cross-sectional study performed in 10 European cities. SUBJECTS/METHODS: Iron status was defined utilising biochemical indicators. Iron depletion was defined as low serum ferritin (SF8.5 mg/l) plus iron depletion. Iron deficiency anaemia (IDA) was defined as ID with haemoglobin (Hb) below the WHO cutoff for age and sex: 12.0 g/dl for girls and for boys aged 12.5-14.99 years and 13.0 g/dl for boys aged ≥15 years. Enzyme linked immunosorbent assay was used as analytical method for SF, sTfR and C-reactive protein (CRP). Subjects with indication of inflammation (CRP >5 mg/l) were excluded from the analyses. A total of 940 adolescents aged 12.5-17.49 years (438 boys and 502 girls) were involved. RESULTS: The percentage of iron depletion was 17.6%, significantly higher in girls (21.0%) compared with boys (13.8%). The overall percentage of ID and IDA was 4.7 and 1.3%, respectively, with no significant differences between boys and girls. A correlation was observed between log (SF) and Hb (r = 0.36, P < 0.01), and between log (sTfR) and mean corpuscular haemoglobin (r = -0.30, P < 0.01). Iron body stores were estimated on the basis of log (sTfR/SF). A higher percentage of negative values of body iron was recorded in girls (16.5%) with respect to boys (8.3%), and body iron values tended to increase with age in boys, whereas the values remained stable in girls. CONCLUSIONS: To ensure adequate iron stores, specific attention should be given to girls at European level to ensure that their dietary intake of iron is adequate.status: publishe