David Martínez-Gómez

Influence of socioeconomic factors on fitness and fatness in Spanish adolescents: The AVENA study

OBJECTIVE This study was to examine the influence of socioeconomic status on fitness and fatness in Spanish adolescents. SUBJECTS AND METHODS A total of 1 795 adolescents (833 boys) aged 12.5-18.5 years from the AVENA study participated in this study. The following physical fitness components were assessed: muscular strength (standing long jump), speed-agility (4 × 10 m shuttle run) and cardiorespiratory fitness (20 m shuttle run). Total and central body fat was assessed using skinfold thickness and waist circumference, respectively. Both parents reported their educational and professional level. RESULTS Girls with higher paternal educational level and boys with higher either maternal or paternal professional level had higher muscular strength levels (all P<0.05). Speed-agility and cardiorespiratory fitness were not associated with parental educational or professional levels in boys. In contrast, girls with higher paternal educational level or higher parental professional level had higher levels in both fitness components (all P<0.05). A higher maternal educational level was associated with lower total and central body fat in boys (all P<0.05), but not in girls. We observed a small effect size (Cohens d∼0.2) in most of these associations. CONCLUSIONS Our results suggest modest associations of high socioeconomic status with better fitness and fatness levels in Spanish adolescents. These associations greatly depend on the socioeconomic status and fitness parameters studied.

Associations Between Sedentary Behavior and Blood Pressure in Young Children

OBJECTIVE To examine the effect of sedentary behavior on blood pressure (BP) in young children using different indicators of sedentariness. DESIGN Cross-sectional study. SETTING A rural Midwestern US community. PARTICIPANTS Children aged 3 to 8 years (N = 111). Intervention Adiposity was assessed using dual energy x-ray absorptiometry. Objective measurements of sedentary activity were obtained from the accelerometers that participants wore continuously for 7 days. Measurements of television (TV) viewing, computer, and screen time (TV + computer) were obtained via parent report. MAIN OUTCOME MEASURES Systolic and diastolic BP. RESULTS The sample spent a mean of 5 hours per day in sedentary activities, of which 1.5 hours were screen time. Accelerometer-determined sedentary activity was not significantly related to systolic BP or diastolic BP after controlling for age, sex, height, and percentage of body fat. However, TV viewing and screen time, but not computer use, were positively associated with both systolic BP and diastolic BP after adjusting for potential confounders. Participants in the lowest tertile of TV and screen time had significantly lower levels of systolic and diastolic BP than participants in the upper tertile. CONCLUSIONS Sedentary behaviors, particularly TV viewing and screen time, were associated with BP in children, independent of body composition. Other factors that occur during excessive screen time (eg, food consumption) should also be considered in the context of sedentary behavior and BP development in children.

Sedentarismo, adiposidad y factores de riesgo cardiovascular en adolescentes. Estudio AFINOS

Introduccion y objetivos Examinar las asociaciones entre sedentarismo medido de forma objetiva y los factores de riesgo cardiovascular (RC). Un objetivo secundario fue evaluar el grado de asociacion entre adiposidad general y abdominal con factores de RC. Metodos Doscientos diez adolescentes, de 13-17 anos, participaron en este estudio transversal. Se midio la suma de seis pliegues (sum6), perimetro de cintura (PC), presion arterial sistolica (PAS) y diastolica (PAD), glucosa, colesterol total (CT), trigliceridos (TG), colesterol de las lipoproteinas de alta (cHDL) y baja densidad (cLDL) y apolipoproteinas A-1 y B-100. Se calculo un indice de RC (IRC) usando presion arterial media (PAM), TG, cHDL y glucosa. El sedentarismo se valoro con acelerometro durante 7 dias. Se dividio a los participantes en terciles de sedentarismo y en niveles de baja-alta adiposidad general (sum6) y abdominal (PC). Resultados Los adolescentes con niveles altos de sedentarismo tuvieron valores menos favorables de PAS, TG, glucosa e IRC. Los adolescentes con mayor nivel de adiposidad general mostraron diferencias significativas en cinco de once factores analizados (PAD, cLDL, CT, apolipoproteina B-100 e IRC), mientras que los adolescentes con mas adiposidad abdominal tuvieron diferencias en ocho factores (PAS, PAM, cHDL, cLDL, TG, CT, apolipoproteina B-100 e IRC). Los adolescentes con mayor adiposidad general y abdominal y con niveles altos de sedentarismo mostraron un IRC menos favorable. Conclusiones El sedentarismo esta asociado con factores de RC en adolescentes, especialmente en los adolescentes obesos. La adiposidad abdominal parece ser mas importante en el desarrollo de factores de RC que la adiposidad general.

Recommended levels of physical activity to avoid an excess of body fat in European adolescents: the HELENA Study.

BACKGROUND It is unclear how much physical activity is necessary to prevent obesity during adolescence. PURPOSE The purpose of this study was to examine whether the current physical activity guidelines for youth are associated with a lower risk of excess of body fat in European adolescents. METHODS A sample of 2094 adolescents from the HELENA cross-sectional study was selected. Levels of moderate, vigorous, and moderate to vigorous physical activity (MVPA) were assessed using accelerometers. BMI and percentage of body fat (skinfolds) were calculated and used to categorize the adolescents as normal-weight/normal-fat, overweight/overfat, and obese. Data were collected during 2006-2007. Receiver operating characteristic (ROC) analysis, performed in 2009, was used to determine thresholds that best discriminate between weight and body fat categories. RESULTS ROC analysis showed that >/=18 minutes/day in vigorous physical activity and >/=55 minutes/day in MVPA significantly discriminated between normal-weight and overweight+obesity categories. Moreover, >/=9 minutes/day of vigorous physical activity and >/=49 minutes/day of MVPA discriminated between normal-fat and overfat/obese adolescents. Adolescents who did not meet the current physical activity guidelines for youth of 60 minutes/day in MVPA increased the risk of having overweight+obesity (OR=1.24, 95% CI=1.01, 1.534) and overfat+obesity (OR=1.79, 95% CI=1.33, 2.42). ORs increased when adolescents did not meet the guidelines of at least 15 minutes/day in vigorous physical activity. CONCLUSIONS Current physical activity guidelines seem to be appropriate to prevent excess of body fat in European adolescents. However, participation in vigorous physical activity might have additional importance in preventing obesity.

Attenuation of the effect of the FTO rs9939609 polymorphism on total and central body fat by physical activity in adolescents: the HELENA study.

OBJECTIVE To examine whether physical activity attenuates the effect of the FTO rs9939609 polymorphism on body fat estimates in adolescents. DESIGN Cross-sectional study. SETTING Athens, Greece; Dortmund, Germany; Ghent, Belgium; Heraklion, Greece; Lille, France; Pécs, Hungary; Rome, Italy; Stockholm, Sweden; Vienna, Austria; and Zaragoza, Spain, from October 2006 to December 2007. PARTICIPANTS Adolescents from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (n = 752). MAIN EXPOSURE Physical activity. MAIN OUTCOME MEASURES The FTO rs9939609 polymorphism was genotyped. Physical activity was assessed by accelerometry. We measured weight, height, waist circumference, and triceps and subscapular skinfolds; body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]) and body fat percentage were calculated. RESULTS The A allele of the FTO polymorphism was significantly associated with higher BMI (+0.42 per risk allele), higher body fat percentage (+1.03% per risk allele), and higher waist circumference (+0.85 cm per risk allele). We detected significant or borderline gene x physical activity interactions for the studied body fat estimates (for interaction, P = .02, .06, and .10 for BMI, body fat percentage, and waist circumference, respectively). Indeed, the effect of the FTO rs9939609 polymorphism on these body fat parameters was much lower in adolescents who met the daily physical activity recommendations (ie, >/=60 min/d of moderate to vigorous physical activity) compared with those who did not: +0.17 vs +0.65 per risk allele in BMI, respectively; +0.40% vs +1.70% per risk allele in body fat percentage, respectively; and +0.60 vs +1.15 cm per risk allele in waist circumference, respectively. CONCLUSION Adolescents meeting the daily physical activity recommendations may overcome the effect of the FTO rs9939609 polymorphism on obesity-related traits.

Secular trends in health-related physical fitness in Spanish adolescents: The AVENA and HELENA Studies

We analysed the secular trends in health-related physical fitness in Spanish adolescents between 2001-2002 and 2006-2007. Two representative population studies were conducted 5 years apart in adolescents (12.5-17.5 years) from Zaragoza (Spain) that participated in the AVENA study in 2001-2002 and in the HELENA-CSS study in 2006-2007. Both studies used the same tests to assess physical fitness: the handgrip strength, bent arm hang, standing broad jump, 4×10m shuttle run and 20m shuttle run tests. Performance in 4×10m shuttle run and 20m shuttle run tests was higher in 2006-2007 (Cohens d ranging from 0.2 to 0.4, p<0.05), whereas performance in handgrip strength and standing broad jump tests was lower in 2006-2007 (Cohens d ranging from 0.3 to 1.1, p<0.001). Adjustment for age, pubertal status, fat mass, fat free mass and parental education did not alter the results. The odds ratio (OR) of meeting the FITNESSGRAM Standards for healthy cardiorespiratory fitness was higher in 2006-2007 in both boys (OR, 95% CI: 2.123, 1.157-3.908) and girls (OR, 95% CI: 2.420, 1.377-4.255). The results indicate that levels of both speed/agility and cardiorespiratory fitness were higher in 2006-2007 than in 2001-2002, whereas muscular strength components were lower in 2006-2007.

Fiabilidad y validez del cuestionario de actividad física PAQ-A en adolescentes españoles

Reliability and Validity of the PAQ-A Questionnaire to Assess Physical Activity in Spanish Adolescents Background: Questionnaires are feasible instruments to assess physical activity (PA) in large samples. The aim of the current study was to evaluate the reliability and validity of the PAQ-A questionnaire in Spanish adolescents using the measurement of PA by accelerometer as criterion. Methods: In a sample of 82 adolescents, aged 12 to 17 years, 1week PAQ-A test-retest was administered. Reliability was analyzed by the Intraclass Correlation Coefficient (ICC) and the internal consistency by the Cronbach’s α Coefficient. Two hundred thirty-two adolescents, aged 13-17 years, completed the PAQ-A and wore the ActiGraph GT1M accelerometer during 7-days. The PAQ-A was compared against total PA and moderate to vigorous PA (MVPA) obtained by the accelerometer. Results: Test-retest reliability showed ICC = 0.71 for the final score of PAQ-A. Internal consistency was α = 0.65 in the first selfreport, α = 0.67 in the retest in 82 adolescents sample, and α = 0.74 in the 232 adolescents sample. The PAQ-A was moderately correlated with total PA (rho = 0.39) and MVPA (rho= 0.34) assessed by the accelerometer. The PAQ-A obtained significantly moderate correlations in boys but not in girls against the accelerometer. Conclusions: The PAQ-A questionnaire shows an adequate reliability and a reasonable validity for assessing PA in Spanish adolescents.

Comparison of the IPAQ-A and Actigraph in relation to VO2max among European adolescents: The HELENA study

The purpose was to compare data obtained from a modified, long, self-administered version of the International Physical Activity Questionnaire (IPAQ-A) with objective data obtained in parallel from Actigraph accelerometers, and VO(2)max in adolescents. The study comprised a total of 2018 adolescents (46% male) from ten European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Physical activity was assessed over seven consecutive days by accelerometry and expressed as min/day of moderate, vigorous, and moderate to vigorous (MVPA) physical activity (PA). PA was also assessed with the IPAQ-A. VO(2)max was estimated from a 20-m shuttle run test. Poor to fair correlations between the two methodologies were found for the whole study sample and when stratified by age and gender (r(s) = 0.08-0.26, p < 0.01). On average, the self-reported time spent in moderate PA was higher compared to the time measured with the accelerometer, while the differences between both instruments were less clear for vigorous intensity. Adolescents reporting high levels of PA (3rd tertile IPAQ-A) also showed higher levels of PA (accelerometers) in all the study variables (moderate, vigorous and MVPA), compared to adolescents reporting low PA (1st tertile IPAQ-A) (all p < 0.001). Both methods were moderately correlated with estimated VO(2)max. Within the HELENA-study, the IPAQ-A showed the modest comparability with the accelerometer data for assessing PA in each intensity level and was the highest for vigorous intensity. Both instruments are able to detect the adolescents with the highest cardio respiratory fitness, which are the most active adolescents.

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.

Continued sedentariness, change in sitting time, and mortality in older adults.

PURPOSE Prolonged sitting time (ST) is associated with higher mortality. However, previous studies used only a single measure of ST at baseline, so they could not directly assess the effect of continued exposure to high ST, or of changes in ST, on mortality. We prospectively assessed the association of continued sedentariness and of changes in ST for 2 yr with subsequent long-term all-cause mortality. METHODS This study was based on a prospective cohort of 2635 persons representative of the Spanish population 60 yr and older. ST was self-reported in 2001 and 2003. The median of ST was used as the cutoff to define excessive ST. Individuals were classified as consistently sedentary (> median in 2001 and 2003), newly sedentary (≤ median in 2001 and > median in 2003), formerly sedentary (> median in 2001 and ≤ median in 2003), and consistently nonsedentary (≤ median in 2001 and 2003). The association of ST in the period 2001-2003 with all-cause mortality from 2003 through 2011 was assessed with Cox regression and adjusted for the main confounders, including physical activity. RESULTS Among the study participants, 846 died between 2003 and 2011. Compared with persons who were consistently sedentary, the hazard ratios (95% confidence interval) for mortality were 0.91 (0.76-1.10) in those who were newly sedentary, 0.86 (0.70-1.05) in formerly sedentary individuals, and 0.75 (0.62-0.90) in those who remained consistently nonsedentary. The results were similar across strata defined according to obesity, morbidity, functional limitations, or meeting recommendations for physical activity. CONCLUSION Compared with older adults who were consistently sedentary during 2 yr, consistently nonsedentary individuals showed reduced all-cause mortality. Individuals who changed ST experienced an intermediate reduction in mortality.