Luis Gracia-Marco

Physical fitness reference standards in European children: the IDEFICS study

Background/Objectives:A low fitness status during childhood and adolescence is associated with important health-related outcomes, such as increased future risk for obesity and cardiovascular diseases, impaired skeletal health, reduced quality of life and poor mental health. Fitness reference values for adolescents from different countries have been published, but there is a scarcity of reference values for pre-pubertal children in Europe, using harmonised measures of fitness in the literature. The IDEFICS study offers a good opportunity to establish normative values of a large set of fitness components from eight European countries using common and well-standardised methods in a large sample of children. Therefore, the aim of this study is to report sex- and age-specific fitness reference standards in European children.Subjects/Methods:Children (10 302) aged 6–10.9 years (50.7% girls) were examined. The test battery included: the flamingo balance test, back-saver sit-and-reach test (flexibility), handgrip strength test, standing long jump test (lower-limb explosive strength) and 40-m sprint test (speed). Moreover, cardiorespiratory fitness was assessed by a 20-m shuttle run test. Percentile curves for the 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentiles were calculated using the General Additive Model for Location Scale and Shape (GAMLSS).Results:Our results show that boys performed better than girls in speed, lower- and upper-limb strength and cardiorespiratory fitness, and girls performed better in balance and flexibility. Older children performed better than younger children, except for cardiorespiratory fitness in boys and flexibility in girls.Conclusions:Our results provide for the first time sex- and age-specific physical fitness reference standards in European children aged 6–10.9 years.

Levels of Physical Activity That Predict Optimal Bone Mass in Adolescents: The HELENA Study

BACKGROUND Physical activity is necessary for bone mass development in adolescence. There are few studies quantifying the associations between physical activity and bone mass in adolescents. PURPOSE To assess the relationship between moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) and bone mass in adolescents. METHODS Bone mass was measured by dual-energy X-ray absorptiometry and physical activity by accelerometers in 380 healthy Spanish adolescents (189 boys, aged 12.5-17.5 years) from the HELENA-CSS (2006-2007). Subjects were classified according to the recommended amount of MVPA (<60 minutes or ≥60 minutes of MVPA/day). Receiver operating characteristic curve analysis was applied to calculate the relationship between physical activity and bone mass. RESULTS Less than 41 and 45 minutes of MVPA/day are associated with reduced bone mass at the trochanter and femoral neck. More than 78 minutes of MVPA/day is associated with increased bone mineral density (BMD) at the femoral neck. Regarding VPA, more than 28 minutes/day for the hip and intertrochanter and more than 32 minutes/day for the femoral neck are associated with increased BMD. CONCLUSIONS The recommended amount of physical activity (minutes/day) seems insufficient to guarantee increased bone mass. With some minutes of VPA/day, bone adaptations could be obtained at different bone sites.

Sedentary behaviours and socio-economic status in Spanish adolescents: the AVENA study

BACKGROUND This study aimed to describe the influence of socio-economic status (SES) on the prevalence sedentary behaviours among Spanish adolescents. METHODS Cross-sectional data from Spanish adolescents from the Alimentación y Valoración del Estado Nutricional de los Adolescentes (AVENA) Study (2002). A national representative sample of 1776 adolescents aged 13-18.5 years provided information about time spent watching television (TV), playing with computer or videogames and studying. Parental education and occupation were assessed as SES. Participants were categorized by gender, age, parental education and occupation. Logistic regression models were used. RESULTS No gender differences were found for TV viewing. For computer and videogames use (weekdays), more boys played >3 h/day (P < 0.001), whereas a higher percentage of girls reported studying >3 h/day (P < 0.001). Among boys, parental education and occupation were inversely associated with TV viewing, parental occupation directly associated with study and maternal education inversely with computer and videogames use during weekdays (all P < 0.05). For girls, parental occupation was inversely associated with TV viewing. CONCLUSION Spanish adolescents presented different sedentary patterns according to age, gender and SES. Boys reported more time engaged in electronic games, whereas girls reported more time studying. Parental occupation had more influence than parental education on the time spent in sedentary behaviours.

Physical activity does not attenuate the obesity risk of TV viewing in youth.

This study aimed to examine the association of television (TV) time, the frequency of meals while watching TV and the presence of TV set in the bedroom with total and abdominal obesity and to assess whether physical activity (PA) attenuates the obesity risk of TV viewing.

Contribution of social marketing strategies to community-based obesity prevention programmes in children

Objectives:To review child and adolescent obesity prevention programmes to determine whether they have included the Social Marketing Benchmark Criteria (BC). In addition, we analysed whether there was a relationship between the presence of the criteria and the effectiveness of the programme.Methods:Interventions had to be aimed at preventing obesity through behaviour changes relating to diet, physical activity, lifestyle and social support, separately or in combination. A total of 41 interventions were identified in PubMed and Embase that fulfilled the inclusion criteria.Results:The more recent the studies, the greater the number of the BC that seem to have been used. However, regarding behaviour changes, we found the most effective period to be 1997–2002, with 100% of the interventions resulting in behaviour changes (9/9). In addition, almost all interventions resulted in improvements in body composition variables: 5 of 6 for body mass index or overweight/obesity prevalence and 6 of 6 for skin-folds.Conclusions:The presence of a higher number of BC does not assure higher effectiveness. Further research is required in this field. At the moment, studies aimed at preventing obesity in children and adolescents have not included social marketing aspects in their interventions in a comprehensive manner.

Sedentary behaviours and its association with bone mass in adolescents: the HELENA cross-sectional study.

BackgroundWe aimed to examine whether time spent on different sedentary behaviours is associated with bone mineral content (BMC) in adolescents, after controlling for relevant confounders such as lean mass and objectively measured physical activity (PA), and if so, whether extra-curricular participation in osteogenic sports could have a role in this association.MethodsParticipants were 359 Spanish adolescents (12.5-17.5 yr, 178 boys,) from the HELENA-CSS (2006–07). Relationships of sedentary behaviours with bone variables were analysed by linear regression. The prevalence of low BMC (at least 1SD below the mean) and time spent on sedentary behaviours according to extracurricular sport participation was analysed by Chi-square tests.ResultsIn boys, the use of internet for non-study was negatively associated with whole body BMC after adjustment for lean mass and moderate to vigorous PA (MVPA). In girls, the time spent studying was negatively associated with femoral neck BMC. Additional adjustment for lean mass slightly reduced the negative association between time spent studying and femoral neck BMC. The additional adjustment for MVPA did not change the results at this site. The percentage of girls having low femoral neck BMC was significantly smaller in those participating in osteogenic sports (≥ 3 h/week) than in the rest, independently of the cut-off selected for the time spent studying.ConclusionsThe use of internet for non-study (in boys) and the time spent studying (in girls) are negatively associated with whole body and femoral neck BMC, respectively. In addition, at least 3 h/week of extra-curricular osteogenic sports may help to counteract the negative association of time spent studying on bone health in girls.

Seasonal variation in physical activity and sedentary time in different European regions. The HELENA study

Abstract This report aims (1) to examine the association between seasonality and physical activity (PA) and sedentary time in European adolescents and (2) to investigate whether this association was influenced by geographical location (Central-North versus South of Europe), which implies more or less extreme weather and daylight hours. Valid data on PA, sedentary time and seasonality were obtained in 2173 adolescents (1175 females; 12.5–17.5 years) included in this study. Physical activity and sedentary time were measured by accelerometers. ANCOVA was conducted to analyse the differences in PA and sedentary time across seasons. Results showed that girls had lower levels of moderate to vigorous PA (MVPA) and average PA, and spent more time in sedentary activities in winter compared with spring (all P < 0.05). Stratified analyses showed differences in PA and sedentary time between winter and spring in European girls from Central-North of Europe (P < 0.05 for sedentary time). There were no differences between PA and sedentary time across seasonality in boys. In conclusion, winter is related with less time spent in MVPA, lower average PA and higher time spent in sedentary activities in European adolescent girls, compared with spring. These differences seem to mainly occur in Central-North Europe.

Bone Mass and Bone Metabolism Markers during Adolescence: The HELENA Study

Background/Aims: The assessment of bone mineral content (BMC) and density (BMD) status in children and adolescents is important for health and the prevention of diseases. Bone metabolic activity could provide early information on bone mass development. Our aim was to describe bone mass and metabolism markers according to age and Tanner stage in adolescents. Methods: Spanish adolescents (n = 345; 168 males and 177 females) aged 12.5–17.5 years participated in this cross-sectional study. Body composition variables were measured by dual-energy X-ray absorptiometry. Serum osteocalcin (n = 101), aminoterminal propeptide of type I procollagen (n = 92) and β-isomerized C-telopeptides (β-CTX, n = 65) and urine samples (β-CTX; n = 237) were analyzed by electrochemiluminescence immunoassay. Results: Analysis of covariance showed that females had higher values for BMC and BMD in most of the regions. Both males and females had a significant decrease in bone markers while sexual maturation increases (all p < 0.05). Males had an increased bone turnover compared to females (all p < 0.05, except for urine β-CTX in Tanner ≤IV). Conclusion: Our results support the evidence of dimorphic site-specific bone accretion between sexes and show an increased bone turnover in males, suggesting higher metabolic activity.

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 12.5-17.5 years, 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.

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

BACKGROUND 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. AIM To determine how body composition and physical fitness are related to 25-hydroxyvitamin D [25(OH)D] concentrations in European adolescents. DESIGN The HEalthy Lifestyle in Europe by Nutrition in Adolescence-CSS study was a multi-centre cross-sectional study. METHODS 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. RESULTS 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). CONCLUSION 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.