Lifestyle In Europe Research Articles

Clustering of Multiple Lifestyle Behaviors and Health-related Fitness in European Adolescents

To explore the clustering of different lifestyle behaviors and whether this clustering differs by gender, age, and health-related fitness. Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study. Ten European cities. A total of 2,084 adolescents (12.5-17.5 years). 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. Hierarchical method and κ-means cluster analysis. Analysis of variance tests. 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 speed-agility, whereas girls presented higher aerobic capacity, strength, and speed-agility. 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.

Cardiorespiratory fitness in males, and upper limbs muscular strength in females, are positively related with 25-hydroxyvitamin D plasma concentrations in European adolescents: the HELENA study

High prevalence of vitamin D insufficiency (<75 nmol/l) has been previously reported in European adolescents. Vitamin D deficiency has been related to physical fitness and adiposity but it is not clearly known whether this relationship applies to growing children and adolescents. To determine how body composition and physical fitness are related to 25-hydroxyvitamin D [25(OH)D] concentrations in European adolescents. The HEalthy Lifestyle in Europe by Nutrition in Adolescence-CSS study was a multi-centre cross-sectional study. Plasma 25(OH)D, body composition and physical fitness measures were obtained in 1006 European adolescents (470 males) aged 12.5-17.5 years. Stepwise regression and ANCOVA were performed by gender using 25(OH)D as dependent variable, with body composition, physical fitness as independent variables controlling for age, seasonality and latitude. For males, maximum oxygen consumption (VO2max) (B = 0.189) and body mass index (BMI) (B = -0.124) were independently associated with 25(OH)D concentrations (both P < 0.05). For females, handgrip strength (B = 0.168; P < 0.01) was independently associated with 25(OH)D concentrations. Those adolescents at lower BMI and high fitness score presented significant higher 25(OH)D concentrations than those at lower fitness score in the other BMI groups (P < 0.05). Cardiorespiratory fitness and upper limbs muscular strength are positively associated with 25(OH)D concentrations in male and female adolescents, respectively. Adiposity in males and low fat free mass in females are related to hypovitaminosis D. The interaction between fitness and BMI has a positive effect on 25(OH)D concentrations. Therapeutic interventions to correct the high rates of vitamin D deficiency in adolescents should consider physical fitness.

Egg intake and cardiovascular risk factors in adolescents: role of physical activity; the HELENA study

Cardiovascular diseases (CVDs) represent the main cause of morbi-mortality in western countries. Serum cholesterol levels have been related to cardiovascular disease (CVD). Egg intake has been indirectly related to the risk of developing CVD because of its high cholesterol content. The aim of the present study was to examine the association between egg intake and CVD risk factors in adolescents, assessing the possible influence of physical activity. We studied 380 adolescents enrolled in the HELENA (HEalthy Lifestyle in Europe by Nutrition in Adolescence) study. Food intake was estimated by 2 nonconsecutive 24 h recalls. We measured adiposity indicators, lipid profile, blood glucose and insulin levels, insulin resistance, blood pressure and cardiorespiratory fitness. A CVD risk score was computed as a measure of the overall CVD risk profile. Physical activity was objectively measured by accelerometry. Sexual development was examined. Socioeconomic and smoking statuses were obtained by questionnaire. The association between egg intake and CVD risk factors was examined using a multilevel analysis adjusted for potential confounders. Egg intake was not associated with lipid profile, adiposity, insulin resistance, blood pressure, cardiorespiratory fitness or the integrated CVD risk score. This lack of association was not influenced by physical activity. The findings of the present study suggest that egg intake is not associated with a less favorable lipid or CVD risk profile in adolescents. This lack of association is not influenced by the level of physical activity.

Dietary and lifestyle quality indices with/without physical activity and markers of insulin resistance in European adolescents: the HELENA study

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.

Genetic and Molecular Insights Into the Role of PROX1 in Glucose Metabolism

Genome-wide association studies have shown that the rs340874 single nucleotide polymorphism (SNP) in PROX1 is a genetic susceptibility factor for type 2 diabetes. We conducted genetic and molecular studies to better understand the role of PROX1 in type 2 diabetes. We assessed the impact of the whole common genetic variability of PROX1 (80 SNPs) on type 2 diabetes–related biochemical traits in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study (n = 1,155). Three SNPs (rs340838, rs340837, and rs340836) were significantly associated with fasting plasma insulin levels (P ≤ 0.00295). We evaluated the impact of nine PROX1 SNPs (the three insulin-associated SNPs plus six SNPs in strong linkage disequilibrium) on luciferase reporter gene expression. The insulin-lowering alleles of rs340874, rs340873, and rs340835 were associated with lower luciferase activity in MIN6 and HepG2 cells (except for rs340874, which was in HepG2 cells only). Electrophoretic mobility shift assays indicated that specific nuclear protein bindings occur at the three SNPs in HepG2 cells, with allele-binding differences for rs340874. We also showed that the knockdown of Prox1 expression by small interfering RNAs in INS-1E cells resulted in a 1.7-fold reduction in glucose-stimulated insulin secretion. All together, we propose that reduced expression of PROX1 by cis-regulatory variants results in altered β-cell insulin secretion and thereby confers susceptibility to type 2 diabetes.

Association between self-reported sleep duration and dietary quality in European adolescents

Evidence has grown supporting the role for short sleep duration as an independent risk factor for weight gain and obesity. The purpose of the present study was to examine the relationship between sleep duration and dietary quality in European adolescents. The sample consisted of 1522 adolescents (aged 12.5-17.5 years) participating in the European multi-centre cross-sectional ‘Healthy Lifestyle in Europe by Nutrition in Adolescence’ study. Sleep duration was estimated by a self-reported questionnaire. Dietary intake was assessed by two 24 h recalls. The Diet Quality Index for Adolescents with Meal index (DQI-AM) was used to calculate overall dietary quality, considering the components dietary equilibrium, dietary diversity, dietary quality and a meal index. An average sleep duration of ≥ 9 h was classified as optimal, between 8 and 9 h as borderline insufficient and < 8 h as insufficient. Sleep duration and the DQI-AM score were positively associated (β = 0.027, r 0.130, P< 0.001). Adolescents with insufficient (62.05 (sd 14.18)) and borderline insufficient sleep (64.25 (sd 12.87)) scored lower on the DQI-AM than adolescents with an optimal sleep duration (64.57 (sd 12.39)) (P< 0.001; P= 0.018). The present study demonstrated in European adolescents that short sleep duration was associated with a lower dietary quality. This supports the hypothesis that the health consequences of insufficient sleep may be mediated by the relationship of insufficient sleep to poor dietary quality.

Nutrient intake of European adolescents: results of the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.

An adequate nutritional intake in childhood and adolescence is crucial for growth and the prevention of youth and adult obesity and nutrition-related morbidities. Improving nutrient intake in children and adolescents is of public health importance. The purpose of the present study was to describe and evaluate the nutrient intake in a European sample using the D-A-CH nutrient intake recommendations and the Nutritional Quality Index (NQI). The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study is a cross-sectional study, the main objective of which is to obtain comparable data on a variety of nutritional and health-related parameters in adolescents aged 12·5-17·5 years. Eight cities in Europe. The initial sample consisted of 3528 European adolescents. Among these, 1590 adolescents (54% female) had sufficient and plausible dietary data on energy and nutrient intakes from two 24 h recalls using the HELENA-DIAT software. The intakes of most macronutrients, vitamins and minerals were in line with the D-A-CH recommendations. While the intakes of SFA and salt were too high, the intake of PUFA was too low. Furthermore, the intakes of vitamin D, folate, iodine and F were less than about 55% of the recommendations. The median NQI was about 71 (of a maximum of 100). The intakes of most nutrients were adequate. However, further studies using suitable criteria to assess nutrient status are needed. Public health initiatives should educate children and adolescents regarding balanced food choices.

Échec précoce chez les patients incidents en dialyse péritonéale

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.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.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.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.

Sleep duration and lymphocyte subsets profile in European adolescents. The HELENA Study

Insufficient sleep is associated with higher incidence of infections and worse recovery, and more recently with increased risk for noninfectious diseases and low-grade inflammation (1) . The immune system seems to be strongly influenced by the sleep/wake cycle and has its own circadian rhythm, in both its functions and circulating cell numbers (2) . During adolescence sleep patterns experience significant changes, such as delay of sleep initiation and/or reduction of the sleep duration; therefore, sleeping habits at this period may have an impact on the immune system. In the present work, absolute and relative counts of leukocyte types and lymphocyte subsets were compared between adolescents reporting to sleep less than 8 hours per night (short-sleep group) and those reporting 8 hours or more (sufficient sleep). Blood samples were collected after an overnight fast from 1,089 boys and girls (12.5‐17.5 years old; 53.3% females) participating in the HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence-Cross-Sectional Study). Leukocyte and lymphocyte subset counts were compared by means of analysis of covariance (ANCOVA), adjusting for country, gender, Tanner stage and body mass index (BMI). Non-normally distributed variables were previously log-transformed. Adolescents in the short-sleep group ( < 8h/night) presented higher counts and percentages of total T (CD3 + ; P < 0.05) and helper T (CD4 + ; P < 0.01) lymphocytes, higher counts of total memory T cells (CD3 + RO + ; P < 0.05) and memory helper T cells (CD4 + RO + ; P < 0.001), and lower percentages of natural killer cells (CD3 - CD16 + 56 + ; P < 0.05), independently of gender and BMI. Our results show a significant relationship between sleep duration and immune parameters in European adolescents, suggesting that sleep-related immune alterations can start at early life stages.

Lymphocyte subsets, anthropometric measurements and body composition in European adolescents. The HELENA Study

There is a close relationship between obesity and the immune system. Obese individuals have been shown to present higher immune cell counts, mainly of total leukocytes, but also of neutrophils, lymphocytes and monocytes (1) . The association between leukocyte count and obesity has been observed in children and adolescents as well (2,3) , and it could also occur with other cell types, e.g., T lymphocytes (4) . We have recently found a significant relation between total leukocytes and body mass index (BMI) in a cohort of European adolescents participating in the HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence-Cross-Sectional Study) (unpublished data). For the present work we studied further the relationships between lymphocyte subset counts and body composition and anthropometric measurements in this adolescent cohort. Blood samples were collected after an overnight fast from 1,089 boys and girls (12.5‐17.5 years). After applying exclusion criteria to rule out possible infections, data were analysed from 751 adolescents (47.5% males). The sample was divided into three categories according to tertiles of standardized BMI values. Absolute and relative numbers of total T lymphocytes

White blood cell count is associated with features of the metabolic syndrome in European adolescents. The HELENA Study

The aim of the present work was to analyse the relationships between WBCC and obesity and features of the metabolic syndrome in a cohort of European adolescents participating in the HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence-CrossSectional Study). Blood samples were collected after an overnight fast from 1,089 participants aged 12.5‐17.5 years. After applying exclusion criteria (having fever and/or having received any medical treatment 24 hours prior to extraction), data were analysed from 952 adolescents (47.3% males). The sample was divided into four categories according to WBCC quartiles. Height, weight, body mass index (BMI), body fat mass and percentage, waist circumference, blood pressure (SBP and DBP), serum glucose, lipids, insulin, and indices of insulin resistance (HOMA-IR) and sensitivity (QUICKY-IS) were compared between groups by analysis of covariance (ANCOVA), adjusting for country, gender and age. Non-normally distributed variables were previously log-transformed. According to our data, adolescents with higher WBCC presented significantly higher weight (P < 0.01), BMI, body fat, waist circumference (all P < 0.001), DBP (P < 0.01), serum triglycerides (P < 0.001), total cholesterol/HDL-cholesterol and LDL/HDL-cholesterol ratios (P < 0.01), serum insulin and HOMA-IR index (both P < 0.001), and significantly lower values of serum HDL-cholesterol and QUICKY-IS index (both P < 0.001). These results support a significant positive association between WBCC and obesity and metabolic syndrome, and suggest that WBCC can be a useful marker to assess cardio-metabolic risk in European adolescents.

Factors Associated with Vitamin D Deficiency in European Adolescents: The HELENA Study

Evidence indicates low 25-hydroxyvitamin D [(25(OH)D] concentrations in European adolescents. Identification of potential determinants is therefore essential to guide public health initiatives aiming at optimizing vitamin D status across Europe. The aim of the study was to identify potential influencing factors of 25(OH)D concentrations in European adolescents aged 12.5 to 17.5 y, participating in the multi-centre cross-sectional Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. A subset of 1,006 participants (46.8% males) was drawn from the main study. Measures of body composition, biochemical markers, socioeconomic status, dietary intake, physical activity, fitness, sleep time and vitamin D genetic polymorphism (rs1544410) were assessed. Stepwise multivariate linear regression analysis was conducted stratified by gender. In males, linear regression of 25(OH)D, suggested that (1) winter season (β=-0.364; p<0.01), (2) higher latitudes (β=-0.246; p<0.01), (3) BMI z-score (β=-0.198; p<0.05) and (4) retinol concentration (β=0.171; p<0.05) independently influenced 25(OH)D concentrations. In females, (1) winter season (β=-0.370; p<0.01), (2) sleep time (β=-0.231; p<0.01), (3) supplement intake (β=0.221; p<0.05), (4) flexibility (β=0.184; p<0.05), (5) body fat % (β=0.201; p<0.05) (6), BMI z-score (β=-0.272; p<0.05), (7) higher latitudes (β=-0.219; p<0.01) and (8) handgrip strength (β=0.206; p<0.05) independently influenced 25(OH)D concentrations. Season, latitude, fitness, adiposity, sleep time and micronutrient supplementation were highly related to 25(OH)D concentrations found in European adolescents.

Combined influence of healthy diet and active lifestyle on cardiovascular disease risk factors in adolescents

To investigate the combined influence of diet quality and physical activity on cardiovascular disease (CVD) risk factors in adolescents, adolescents (n = 1513; 12.5-17.5 years) participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence study were studied. Dietary intake was registered using a 24-h recall and a diet quality index was calculated. Physical activity was assessed by accelerometry. Lifestyle groups were computed as: healthy diet and active, unhealthy diet but active, healthy diet but inactive, and unhealthy diet and inactive. CVD risk factor measurements included cardiorespiratory fitness, adiposity indicators, blood lipid profile, blood pressure, and insulin resistance. A CVD risk score was computed. The healthy diet and active group had a healthier cardiorespiratory profile, fat mass index (FMI), triglycerides, and high-density lipoprotein cholesterol (HDL-C) levels and total cholesterol (TC)/HDL-C ratio (all P ≤ 0.05). Overall, active adolescents showed higher cardiorespiratory fitness, lower FMI, TC/HDL-C ratio, and homeostasis model assessment index and healthier blood pressure than their inactive peers with either healthy or unhealthy diet (all P ≤ 0.05). Healthy diet and active group had healthier CVD risk score compared with the inactive groups (all P ≤ 0.02). Thus, a combination of healthy diet and active lifestyle is associated with decreased CVD risk in adolescents. Moreover, an active lifestyle may reduce the adverse consequences of an unhealthy diet.

Gender and age influence blood folate, vitamin B12, vitamin B6, and homocysteine levels in European adolescents: the Helena Study

It is important to be able to evaluate vitamin status correctly at any age, but this is especially vital during adolescence since there are higher requirements for healthy growth and development. However, there are no currently available B-vitamin reference values for healthy adolescents. The aim of the present study is to assess the vitamin B status in European adolescents in order to contribute to the development of reference values for selected B-vitamins and total homocysteine (tHcy). Within the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) cross-sectional study, a sub sample of 1051 (499 males, 552 females) adolescents from ten European cities aged 12.5 to 17.49 were analyzed for fasting plasma folate (PF), red blood cell (RBC) folate, serum cobalamin (Cbl), holo-transcobalamin (Holo-TC), Vitamin B6 (PLP), and tHcy. The level of significance was set at P < .05. Following the current cut-off for adults, 2% had low Cbl and 5% had low holo-TC concentrations. Low concentrations of both PF and RBC folate were identified in 10%. Five percent had PLP concentrations <20 nmol/L and 20% <30 nmol/L. Moreover, 5% had high tHcy; median values for the whole sample were: PF 16.0 nmol/L, RBC folate 721.9 nmol/L, Cbl 319 pmol/L, Holo-TC 57.8 pmol/L, and tHcy 6.7 μmol/L. Females had significantly higher median Cbl but lower PLP and tHcy concentrations (P < .01). THcy increased (P < .001) and PF (P < .001) concentrations decreased across age categories. Subjects showed significantly higher tHcy values at the fifth percentile of PF, corresponding with 7.5 nmol/L. Sex and age had an influence on most of the studied biomarkers and should be taken into account. The HELENA percentile distribution is consistent with data from smaller studies and could be used as reference value to characterize B-vitamin status of European adolescents.

Food Consumption and Screen-Based Sedentary Behaviors in European Adolescents

To examine the association between time spent on different sedentary behaviors and consumption of certain food and beverage groups in a sample of European adolescents. Data from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-sectional Study. Eight survey centers (Athens, Dortmund, Ghent, Lille, Rome, Stockholm, Vienna, and Zaragoza). A total of 2202 participants (45.5% boys) aged 12½ to 17½ years. Information on sedentary behaviors (weekdays and weekends) collected via a standardized self-reported questionnaire, including watching television, playing computer and video games, using the Internet for studying or recreation, and studying. Food and beverage consumption data of selected groups were obtained using 2 nonconsecutive 24-hour recalls. Boys reporting more than 4 h/d of watching television, playing computer games, and using the Internet for recreation were more likely to consume sweetened beverages (weekends) (odds ratio [OR], 1.83 [95% CI, 1.21-2.75]; 1.99 [1.31-3.01]; and 1.73 [1.03-2.91], respectively), and less likely to consume fruit (weekdays) (0.39 [0.21-0.72], 0.37 [0.18-0.77], and 0.39 [0.19-0.78], respectively) than those who spent less than 2 h/d. Girls spending more time per day watching television and playing computer or video games (weekdays) and playing computer games or surfing the Internet for recreation (weekends) were more likely to drink sweetened beverages (OR, 1.89 [95% CI, 1.21-2.94]; 1.57 [1.00-2.46]; 2.14 [1.16-3.97]; and 2.30 [1.24-4.28], respectively) and less likely to consume fruit (weekdays) (0.43 [0.23-0.80], 0.40 [0.19-0.83], 0.37 [0.14-0.94], and 0.42 [0.20-0.85], respectively) than those who spent less than 2 h/d. Increased television viewing and computer and Internet use during adolescence is associated with higher odds of consumption of sweetened beverages and lower odds of fruit consumption.

Validation of the Diet Quality Index for Adolescents by comparison with biomarkers, nutrient and food intakes: the HELENA study

Food-based dietary guidelines (FBDG) aim to address the nutritional requirements at population level in order to prevent diseases and promote a healthy lifestyle. Diet quality indices can be used to assess the compliance with these FBDG. The present study aimed to investigate whether the newly developed Diet Quality Index for Adolescents (DQI-A) is a good surrogate measure for adherence to FBDG, and whether adherence to these FBDG effectively leads to better nutrient intakes and nutritional biomarkers in adolescents. Participants included 1804 European adolescents who were recruited in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study. Dietary intake was assessed by two, non-consecutive 24 h recalls. A DQI-A score, considering the components' dietary quality, diversity and equilibrium, was calculated. Associations between the DQI-A and food and nutrient intakes and blood concentration biomarkers were investigated using multilevel regression analysis corrected for centre, age and sex. DQI-A scores were associated with food intake in the expected direction: positive associations with nutrient-dense food items, such as fruits and vegetables, and inverse associations with energy-dense and low-nutritious foods. On the nutrient level, the DQI-A was positively related to the intake of water, fibre and most minerals and vitamins. No association was found between the DQI-A and total fat intake. Furthermore, a positive association was observed with 25-hydroxyvitamin D, holo-transcobalamin and n-3 fatty acid serum levels. The present study has shown good validity of the DQI-A by confirming the expected associations with food and nutrient intakes and some biomarkers in blood.

Daily sugar-sweetened beverage consumption and insulin resistance in European adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.

The present study aimed to evaluate the relationship between the consumption of selected food groups and insulin resistance, with an emphasis on sugar-sweetened beverages (SSB). The present research is a large multicentre European study in adolescents, the HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study). Homeostasis model assessment-insulin resistance index (HOMA-IR) was calculated. Several anthropometric and lifestyle characteristics were recorded. Dietary assessment was conducted by using a short FFQ. The participants were a subset of the original sample (n 546) with complete data on glucose, insulin and FFQ. All participants were recruited at schools. Median (25th, 75th percentile) HOMA-IR was 0.62 (0.44, 0.87). Mean HOMA-IR was significantly higher among adolescents consuming brown bread ≤1 time/week than among those consuming 2-6 times/week (P = 0·011). Mean values of HOMA-IR were also higher in adolescents consuming SSB >5 times/week compared with those consuming less frequently, although a statistically significant difference was detected between those consuming SSB 5-6 times/week and 2-4 times/week (P = 0.049). Multiple linear regression analysis showed that only the frequency of SSB consumption was significantly associated with HOMA-IR after controlling for potential confounders. In particular, it was found that HOMA-IR levels were higher among adolescents consuming SSB 5-6 times/week and ≥1 time/d compared with those consuming ≤1 time/week by 0.281 and 0.191 units, respectively (P = 0.009 and 0.046, respectively). The present study revealed that daily consumption of SSB was related with increased HOMA-IR in adolescents.

Associations of Dietary Calcium, Vitamin D, Milk Intakes, and 25-Hydroxyvitamin D With Bone Mass in Spanish Adolescents: The HELENA Study

Adequate nutrition is needed for the accrual of bone mass during the pre- and postpubertal growth periods. This study aimed to examine the associations between dietary calcium, vitamin D (calciferol), and milk intakes and 25-hydroxyvitamin D [25(OH)D] status and bone mineral content (BMC) and bone mineral density (BMD) in Spanish adolescents, aged 12.5–17.5yr, participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS). Bone mass was measured with dual-energy X-ray absorptiometry and diet via 2 nonconsecutive 24-h dietary recalls (n=227; 48% males). A random subsample of 101 adolescents (46% males) had available measures of 25(OH)D. Multiple linear regression was applied. Significant adjusted associations were observed in males, among milk intakes and BMC and BMD. Also in males, whole-body, head, and right arm BMD were positively related to calcium intakes. In females, 25(OH)D was positively related among others to whole-body, subtotal, and left and right arm BMC and BMD. It could be speculated that diet is not a limiting factor of bone mass development in this group of healthy adolescents, and further research on the effect of other factors in addition to diet in a larger sample should be undertaken.

Iron and vitamin status biomarkers and its association with physical fitness in adolescents: the HELENA study

There is a lack of studies that analyze the association between micronutrient-related biomarker status and physical fitness in adolescents. In the present study, biochemical parameters for iron and vitamin status were studied, along with objective measures of physical fitness in healthy male and female European adolescents. One thousand eighty-nine adolescents (580 girls, 12.5-17.5 yr) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study were included. Hierarchical linear models were performed to determine the associations between micronutrient biomarkers and physical fitness. Age, seasonality, latitude, body mass index, menarche (in girls), and physical activity were used as covariates. For cardiorespiratory fitness, concentrations of hemoglobin, retinol, and vitamin C in male adolescents and β-carotene and 25(OH)D in female adolescents were associated with maximal oxygen consumption. For muscular fitness, concentrations of hemoglobin, β-carotene, retinol, and α-tocopherol in male adolescents and β-carotene and 25(OH)D in female adolescents were associated with better performance of the standing long jump test. In summary, concentrations of hemoglobin and most antioxidant vitamins in male adolescents and β-carotene and 25(OH)D in female adolescents were positively associated with cardiorespiratory and muscular fitness, after controlling for relevant confounders. The associations between physical fitness and iron or vitamin status observed in this cross-sectional study in adolescents should be followed up by a study specifically designed to evaluate causal relationships.

Evaluation of food and nutrient intake assessment using concentration biomarkers in European adolescents from the Healthy Lifestyle in Europe by Nutrition in Adolescence study

Accurate food and nutrient intake assessment is essential for investigating diet-disease relationships. In the present study, food and nutrient intake assessment among European adolescents using 24 h recalls (mean of two recalls) and a FFQ (separately and the combination of both) were evaluated using concentration biomarkers. Biomarkers included were vitamin C, β-carotene, DHA+EPA, vitamin B12 (cobalamin and holo-transcobalamin) and folate (erythrocyte folate and plasma folate). For the evaluation of the food intake assessment 390 adolescents were included, while 697 were included for the nutrient intake assessment evaluation. Spearman rank and Pearson correlations, and validity coefficients, which are correlations between intake estimated and habitual true intake, were calculated. Correlations were higher between frequency of food consumption (from the FFQ) and concentration biomarkers than between mean food intake (from the recalls) and concentration biomarkers, especially for DHA+EPA (r 0·35 v. r 0·27). Most correlations were higher among girls than boys. For boys, the highest validity coefficients were found for frequency of fruit consumption (0·88) and for DHA+EPA biomarker (0·71). In girls, the highest validity coefficients were found for fruit consumption frequency (0·76), vegetable consumption frequency (0·74), mean fruit intake (0·90) and DHA+EPA biomarker (0·69). After exclusion of underreporters, correlations slightly improved. Correlations between usual food intakes, adjusted for food consumption frequency, and concentration biomarkers were higher than correlations between mean food intakes and concentration biomarkers. In conclusion, two non-consecutive 24 h recalls in combination with a FFQ seem to be appropriate to rank subjects according to their usual food intake.