New indices in predicting cardiometabolic risk and its relation to endothelial dysfunction in adolescents: The HELENA study.

BACKGROUND AND AIMS: Blood pressure (BP) changes and insulin resistance (IR) are important cardiometabolic risk (CMR) factors; their early identification can contribute to the reduction of cardiovascular events in adulthood. This necessitates the search for more accessible and easily applied indicators for their prediction. Therefore, this study aimed to evaluate the predictive power of the indices, TyG, TG/HDL-c, height-corrected lipid accumulation product (HLAP), and visceral adiposity index (VAI), in identifying the CMR obtained by high BP and IR and to verify their relationship with biomarkers of endothelial dysfunction (ED) in European adolescents. METHODS AND RESULTS: The anthropometric data and blood biomarkers of 744 adolescents (343 boys and 401 girls) from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS), with a mean age of 14.67 (SD 1.15) years, were assessed. The adolescents were then classified according to the presence or absence of high BP and IR. The cut-off points of the indices evaluated for the identification of CMR were determined. The relationship between CMR diagnosed using these indices and ED biomarkers was tested. The HLAP and TG/HDL-c were fair predictors of CMR obtained by IR in male adolescents. These indices showed association with hsCRP in sVCAM-1 in boys, but it lost significance after adjusting for age and body mass index. CONCLUSION: TG/HDL-c and HLAP indices showed a fair performance in predicting CMR, obtained by IR, in male adolescents. ED showed no association with the CMR identified by the indices.

Association between CNTF Polymorphisms and Adiposity Markers in European 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.

How do energy balance-related behaviors cluster in adolescents?

OBJECTIVES: To delineate the clustering of energy balance-related behaviors in adolescents and investigate whether these behaviors are associated with the household socioeconomic status and parental education level. METHODS: Two cross-sectional studies assessed information on sedentary behavior, physical activity, sugar-sweetened beverages and fruit and vegetable consumption, and sleep duration by self-reported questionnaires in adolescents (12.5-17.5 years old) from Maringá/Brazil (BRACAH Study; n = 682) and ten European cities (HELENA Study; n = 1252) from nine different countries. Gender-specific cluster analyses were performed separately for each study, applying a combination of hierarchical and non-hierarchical methods. RESULTS: Girls showed equivalent behaviors: Sedentary; Active; Unhealthy Eating; Healthy Eating; while boys differed (Brazilian: Sedentary; Active; Healthy Eating; European: Sedentary; Healthy; Unhealthy Eating). In Brazil, we found no association between socioeconomic status and parental education. In European girls, the high socioeconomic status and both parents' university degree were associated with Healthy Eating. In European boys, the high socioeconomic status was associated with Unhealthy Eating, and the mothers' university degree was associated with the Healthy cluster. CONCLUSIONS: Adolescents show Sedentary behavior, regardless of their sex, country of origin, or socioeconomic condition.

Effects of clustering of multiple lifestyle-related behaviors on blood pressure in adolescents from two observational studies.

BACKGROUD: Several lifestyle-related behaviors are associated with cardiovascular health outcomes in adolescents. To examine the associations between clustered lifestyle-related behaviors and blood pressure (BP) levels in adolescents. METHODS: Participants were recruited by multistage random cluster in two cross-sectional studies; one conducted in 2006 and 2007 in ten cities from nine European countries: Athens and Heraklion in Greece, Dortmund in Germany, Ghent in Belgium, Lille in France, Pécs in Hungary, Rome in Italy, Stockholm in Sweden, Vienna in Austria, and Zaragoza in Spain; and another conducted in 2007 one city in Brazil (Maringá/PR). Systolic BP (SBP) and diastolic BP (DBP) (outcomes) and clustered behaviors (weekly consumption of fruits and vegetables, weekly consumption of sugar-sweetened beverages, sleep duration, screen time and physical activity) were analyzed. RESULTS: The Healthy Eating cluster was negatively associated with DBP in European girls, ß=-2.46 (-4.62; -0.30), and with SBP in Brazilian boys, ß=-2.79 (-3.10; -0.15). Furthermore, the Unhealthy Eating cluster was associated with increased SBP in European girls, ß=4.54 (1.29; 7.79), and in Brazilian boys, ß=4.10 (0.80; 7.40). CONCLUSION: The Healthy Eating cluster was associated with lower blood pressure, whereas the Unhealthy Eating cluster was associated with increased SBP in adolescents.

Physical Activity Is Associated with Attention Capacity in Adolescents.

OBJECTIVE: To assess the relationships among physical activity, measured objectively, and attention capacity in European adolescents. STUDY DESIGN: The study included 273 adolescents, aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study. Participants wore a uniaxial accelerometer for 7 days to measure physical activity. The d2 Test of Attention was administered to assess attention capacity. Multivariate analyses were used to study the association of attention capacity with each measure of physical activity. Receiver operating characteristic analysis was performed to determine thresholds that best discriminate between low and good attention capacity. RESULTS: After controlling for potential confounding variables (age, sex, body mass index, parental educational level, fat mass, aerobic fitness, and center), adolescents' attention capacity test performances were significantly and positively associated with longer time spent in moderate or moderate-to-vigorous physical activity (MVPA) in free-living conditions (P < .05). Receiver operating characteristic curve analyses revealed that the physical activity thresholds that best discriminated between low/good attention capacities were ≥41 min·day(-1) for moderate, ≥12 min·day(-1) for vigorous, and ≥58 min·day(-1) for MVPA. CONCLUSION: These findings suggest that promoting MVPA may be have a beneficial effect on attention capacity, an important component of cognition, in adolescents.

Family socioeconomic factors are negatively associated with blood pressure in European boys, but not girls, and Brazilian adolescents: Results from two observational studies.

OBJECTIVE: We aimed to estimate the attributable fraction of systolic (SBP) and diastolic blood pressure (DBP) that can be explained by family socioeconomic factors (FSFs) in adolescents using two observational studies. METHODS: Participants were recruited by multistage random cluster in two cross-sectional studies performed in Europe [Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, n = 3308] and Brazil [Brazilian Cardiovascular Adolescent Health (BRACAH) study, n = 991]. SBP and DBP were measured, and FSFs (socioeconomic status and parental education) were self-reported in both studies. The correlations of SBP and DBP with FSFs were examined by multilevel linear regression through two different models (hierarchical and fully adjusted). The generalized attributable fractions of the FSFs were estimated by comparing the models. RESULTS: Our results showed a significant inverse relationship between parental education (father and mother) and SBP in European boys. The higher generalized attributable fraction to SBP was observed in boys (13.2-22.4%). In girls, we found lower generalized attributable fractions to DBP (10.8-12.1% in Brazilian girls and 3.1-3.8% in European girls). CONCLUSIONS: Our findings revealed a significant inverse relationship between parental education and SBP in European boys. FSF also significantly influenced blood pressure in adolescents, mainly in Brazilian adolescents.

More physically active and leaner adolescents have higher energy intake.

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.

Independent and combined effects of physical activity and sedentary behavior on blood pressure in adolescents: gender differences in two cross-sectional studies.

OBJECTIVES: To examine the independent and combined association of physical activity (PA) and sedentary behavior (SB) on both systolic (SBP) and diastolic blood pressure (DBP) in adolescents from two observational studies. METHODS: Participants from two cross-sectional studies, one conducted in Europe (n = 3,308; HELENA study) and the other in Brazil (n = 991; BRACAH study), were selected by complex sampling. Systolic and diastolic blood pressure (outcomes), PA and SB, both independently and combined, and potential confounders were analyzed. Associations were examined by multilevel linear regression. RESULTS: Performing the recommended amount of PA (≥ 60 min/d) attenuated the effect of SB on DBP in BRACAH study girls and in boys from both studies. In contrast, PA did not attenuate the effects of SB on the SBP of girls in the HELENA study. The combination of less than recommended levels of PA with 2-4 h/d of sedentary behavior was found to be associated with increased SBP in boys from both studies. CONCLUSIONS: Meeting current PA recommendations could mediate the association between SB and DBP in both sexes. In boys, the joint effect of low levels of PA and excessive sedentary activity increases SBP levels. Longitudinal studies are required to confirm these findings.

Physical activity, fitness, and serum leptin concentrations in adolescents.

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.