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Our aim in this study was to examine the association between breastfeeding duration and cardiorespiratory fitness, isometric strength, and explosive strength during adolescence. A total of 2567 adolescents (1426 girls) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study aged 12.5-17.5 y were included. Information about duration of any and exclusive breastfeeding was obtained retrospectively by means of a parental questionnaire. The 20-m shuttle run, handgrip strength, and standing long jump tests were used to assess physical fitness. Significant differences among the categories of breastfeeding duration were tested using ANCOVA after adjusting for a set of potential confounders: gestational and current age, birth weight, sexual maturation, fat mass, fat-free mass, maternal education, parental weight status, country, smoking behavior, and days of vigorous physical activity. Longer breastfeeding (either any or exclusive) was associated with a higher performance in the standing long jump test in both boys and girls (P < 0.001), regardless of fat mass, fat-free mass, and the rest of potential confounders. In adolescents who were breastfed for 3-5 mo or [greater than or equal to]6 mo, the risk of having a standing long jump performance below the 5th percentile was reduced by half compared with those who were never breastfed [odds ratio (OR) = 0.54, 95% CI = 0.30-0.96, P < 0.05; and OR = 0.40, 95% CI = 0.22-0.74, P < 0.01, respectively). These findings suggest a role of breastfeeding in determining lower body explosive strength during adolescence. J. Nutr. 140: 1989-1995, 2010. doi: 10.3945/jn.110.123596.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.apergo.2009.02.006 Byline: Thomas R. Waters (a), Arun Garg (b) Abstract: Youth and adolescents are routinely engaged in manual material handling (MMH) tasks that may exceed their strength capability to perform the task and may place them at excessive risk for musculoskeletal disorders. This paper reports on a two-dimensional biomechanical model that was developed to assess MMH tasks performed by youth 3-21 years of age. The model uses age, gender, posture of the youth performing the MMH activity, and weight of the load handled as input, and provides an estimate of the strength demands of the task and spinal disc compression and shear force resulting from the activity as output. The model can be used to assess whether a specific MMH task exceeds the strength demands for youth of certain ages or genders, which of the internal muscle strengths are most affected, and provides information about the estimated spinal disc compression and shear forces on the spine as a result of the specified MMH task. These results would be helpful in deciding whether a task is appropriate for a youth to perform or whether a certain task modification may be sufficient in reducing the physical demands to a level acceptable for a youth of certain age and gender. Author Affiliation: (a) National Institute for Occupational Safety and Health, Division of Applied Research and Technology, 4676 Columbia Parkway, 45226 Cincinnati, OH, USA (b) University of Wisconsin-Milwaukee, P.O. Box 413, 2200 E. Kenwood Blvd., Milwaukee, WI 53201-0413, USA Article History: Received 18 September 2008; Accepted 24 February 2009 Article Note: (footnote) [star] The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

OBJECTIVE: To systematically assess the effect of the adjunctive administration of corticosteroids in the treatment of acute bacterial meningitis. METHODS: We performed a systematic review and meta-analysis by searching several [...]

Background: Episodic excessive alcohol consumption (i.e., binge drinking) is now considered to be a major public health problem, but whereas short- and long-term harmful consequences of this behaviour are clearly established at medical, social and cognitive levels, the cerebral correlates of these impairments are still unknown. Our study explores the midterm cerebral effects of binge-drinking behaviours among young adults. Methods: We selected 2 groups of first-year university students with no history of drinking habits, paired for psychological and behavioural measures on the basis of their expected alcohol consumption during the forthcoming academic year. The binge drinker group expected to have high personal alcohol consumption, whereas the control group expected low consumption. We used a test-retest paradigm within a 9-month period (session 1 in September 2005, session 2 in May 2006). At each testing session, we recorded auditory event-related potentials while the participants performed an emotional valence judgment task. Results: There were no differences between the groups in behavioural or electrophysiological measures at baseline. After 9 months, the binge drinkers had significantly delayed latencies for all event-related potential components (P1, N2, P3b) of emotional auditory processing compared with the control group (p < 0.006), with no behavioural differences. Limitations: As the present study explored the electrophysiological correlates of binge drinking with an emotional task only, the results will have to be extended to other cognitive processes using various experimental tasks. Conclusion: We report the first direct evidence that short-term binge drinking can produce marked cerebral dysfunction undetectable by behavioural measures alone. The observed latency abnormalities, similar to those observed in long-term alcoholism, constitute an electrophysiological marker of slowed cerebral activity associated with binge drinking. Contexte: La consommation excessive episodique d&apos;alcool (alcoolisation paroxystique intermittente) est desormais consideree comme un probleme de sante publique majeur. Or, si les consequences nefastes de ce comportement a breve et a longue echeance sont clairement etablies du point de vue medical, social et cognitif, les correlats cerebraux de ces effets sont encore inconnus. Notre etude se penche sur les consequences de ce comportement sur le cerveau des jeunes adultes a moyen terme. Methodes : Nous avons selectionne 2 groupes d&apos;etudiants universitaires de premiere annee n&apos;ayant pas d&apos;antecedents de consommation reguliere d&apos;alcool et nous les avons apparies en fonction de variables psychologiques et comportementales sur la base de leur consommation prevue d&apos;alcool au cours de l&apos;annee universitaire qui allait debuter. Les participants du groupe susceptible de s&apos;adonner a l&apos;alcoolisation paroxystique intermittente s attendaient a consommer personnellement beaucoup d&apos;alcool, tandis que ceux du groupe temoin s&apos;attendaient a en consommer peu. Nous avons utilise un paradigme test-retest echelonne sur une periode de 9 mois (premiere seance, septembre 2005; deuxieme seance, mai 2006). Lors de chaque seance d&apos;evaluation, nous avons enregistre les potentiels evoques, tandis que les participants effectuaient une tache liee au jugement de la valence emotionnelle. Resultats : II n&apos;y avait aucune difference entre les groupes pour ce qui est des parametres comportementaux ou electrophysiologiques au depart. Apres 9 mois, les adeptes de l&apos;alcoolisation paroxystique intermittente presentaient des latences significativement prolongees pour toutes les composantes des potentiels evoques (Pi, N2, P3b) dans le traitement auditif des stimuli emotionnels, comparativement au groupe temoin (p < 0,006), sans differences sur le plan du comportement. Limites : Etant donne que la presente etude portait uniquement sur les correlats electrophysiologiques de l&apos;alcoolisation paroxystique intermittente lors d&apos;une tache emotionnelle, les resultats devront etre appliques a d&apos;autres processus cognitifs au moyen de taches experimentales diverses. Conclusion : Nous rapportons la premiere preuve directe selon laquelle ce comportement peut produire a court terme une dysfonction cerebrale marquee, qui ne sera pas decelable au moyen d&apos;echelles comportementales uniquement. Les anomalies de latence observves, semblables a celles que l&apos;on note dans l&apos;alcoolisme chronique, sont des marqueurs electrophysiologiques du ralentissement de l&apos;activite cerebrale associe a l&apos;alcoolisation paroxystique intermittente., Introduction Adolescents and young adults are at high risk of initiating alcohol use, which can lead to the development of later alcohol use disorders (1) and is considered to be [...]

Researchers modeling historical heights have typically relied on the restrictive assumption of a normal distribution, only the mean of which is affected by age, income, nutrition, disease, and similar influences. To avoid these restrictive assumptions, we develop a new semiparametric approach in which covariates are allowed to affect the entire distribution without imposing any parametric shape. We apply our method to a new database of height distributions for Italian provinces, drawn from conscription records, of unprecedented length and geographical disaggregation. Our method allows us to standardize distributions to a single age and calculate moments of the distribution that are comparable through time. Our method also allows us to generate counterfactual distributions for a range of ages, from which we derive age-height profiles. These profiles reveal how the adolescent growth spurt (AGS) distorts the distribution of stature, and they document the earlier and earlier onset of the AGS as living conditions improved over the second half of the nineteenth century. Our new estimates of provincial mean height also reveal a previously unnoticed 'regime switch' from regional convergence to divergence in this period.

Objective: To evaluate the diagnostic utility of recommended body mass index (BMI)-based classification systems in detecting excess body fat (BF) in an Afro-Caribbean adolescent population. Subjects: All adolescents aged 12-18 years were invited to participate in the study. A total of 3749 persons participated fully in the study. Result: Males (12.2%) (95% confidence interval (CI): 10.7, 13.9) and females (43.6%) (95% CI: 41.5, 45.7) had excess adiposity. Specificities were high for all cutoff values (range 90.1-99.7%). Sensitivities ranged from 25.7 to 86.4% and from 15.6 to 54.4% for Centre for Disease Control (CDC) and International Obesity Task Force (IOTF) cutoff values, respectively. The mean areas under the receiver-operating characteristic curves ranged from 62.7 to 88.2% in males and 57.7 to 75.1% in females, while positive likelihood ratios ranged from 8.7 to 90.9 for the recommended BMI cutoff values. Conclusions: Overall, the CDC cutoffs had a higher sensitivity than the IOTF cutoffs in screening for excess fat. Specificities were high for cutoff values in both systems and would produce fewer false negatives. doi:10.1038/sj.ejcn.1602913; published online 19 September 2007 Keywords: Caribbean; BMI; body fat; diagnostic accuracy, Introduction Childhood obesity is rapidly becoming a major public health concern in many developing countries (Kosti and Panagiotakos, 2006; Shetty and Schmidhuber, 2006). This global phenomenon has not escaped the [...]

The role of the social characteristics of families on the weight of adolescents is investigated. The relationship between the obesity of parents and the weight of adolescents has both social and genetic components.

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1467-8624.2008.01220.x Byline: Marielle D. Beijersbergen (1), Marian J. Bakermans-Kranenburg (1), Marinus H. van IJzendoorn (1), Femmie Juffer (1) Abstract: The current study examined whether adolescents' attachment representations were associated with differences in emotion regulation during the Adult Attachment Interview (AAI; C. George, N. Kaplan, & M. Main, 1996) and during a mother-adolescent conflict interaction task (Family Interaction Task [FIT]; J. P. Allen et al., 2003). Participants were one hundred and fifty-six 14-year-old adolescents. Dismissing adolescents showed less interbeat interval (IBI) reactivity (indicating less stress) during the AAI than secure adolescents. However, during the FIT, dismissing adolescents showed more IBI reactivity. No differences in physiological reactivity were found between individuals with resolved or unresolved loss or trauma during the AAI or FIT. The results indicate that dismissing adolescents may effectively use a defensive strategy during the AAI but less so in direct conflict interaction with their attachment figure. Author Affiliation: (1)Leiden University Article note: Correspondence concerning this article should be addressed to Marian J. Bakermans-Kranenburg, Centre for Child and Family Studies, Leiden University, P.O. Box 9555, 2300 RB Leiden, The Netherlands. Electronic mail may be sent to bakermans@fsw.leidenuniv.nl.

BACKGROUND: It is well documented that acute exposure to high levels of persistent organic pollutants, such as polychlorinated biphenyls (PCBs), p,p'-dichlorophenyldichloroethylene (p,p'-DDE), and hexa-chlorobenzene (HCB), can affect human health including [...]

Objectives. We examined whether socioeconomic inequalities in smoking and overweight and obesity emerged in early adulthood and the contribution of family background, adolescent smoking, and body mass index to socioeconomic inequalities. Methods. Using data from the National Longitudinal Study of Adolescent Health we employed multinomial regression analyses to estimate relative odds of heavy or light-to-moderate smoking to nonsmoking and of overweight or obesity to normal weight. Results. For smoking, we found inequalities by young adult socioeconomic position in both genders after controlling for family background and smoking during adolescence. However, family socioeconomic position was not strongly associated with smoking in early adulthood. For overweight and obesity, we found socioeconomic inequalities only among women both by young adult and family socioeconomic position after adjusting for birthweight, other family background, and body mass index during adolescence. Conclusions. Socioeconomic inequalities in smoking emerged in early adulthood according to socioeconomic position. Among women, inequalities in overweight or obesity were already evident by family socioeconomic position and strengthened by their own socioeconomic position. The relative importance of family background and current socioeconomic circumstances varied between smoking and overweight or obesity. (doi:10.2105/AJPH.2007.111609)

Increasingly, measures of dietary patterns have been used to capture the complex nature of dietary intake and investigate its association with health. Certain dietary patterns may be important in the prevention of chronic disease; however, there are few investigations in adolescents. The aim of this study was to describe the dietary patterns of adolescents and their associations with sociodemographic factors, nutrient intakes, and behavioral and health outcomes. Analysis was conducted using data collected in the 1995 Australian National Nutrition Survey of participants aged 12-18 y who completed a 108-item FFQ (n = 764). Dietary patterns were identified using factor analysis and associations with sociodemographic factors and behavioral and health outcomes investigated. Factor analysis revealed 3 dietary patterns labeled a fruit, salad, cereals, and fish pattern; a high fat and sugar pattern; and a vegetables pattern, which explained 11.9, 5.9, and 3.9% of the variation in food intakes, respectively. The high fat and sugar pattern was positively associated with being male (P < 0.001), the vegetables pattern was positively associated with rural region of residence (P = 0.004), and the fruit, salad, cereals, and fish pattern was inversely associated with age (P = 0.03). Dietary patterns were not associated with socioeconomic indicators. The fruit, salad, cereals, and fish pattern was inversely associated with diastolic blood pressure (P = 0.0025) after adjustment for age, sex, and physical activity in adolescents [greater than or equal to] 16 y. This study suggests that specific dietary patterns are already evident in adolescence and a dietary pattern rich in fruit, salad, cereals, and fish pattern may be associated with diastolic blood pressure in older adolescents.

Few studies have systematically used a total diet approach to classify adolescent dietary patterns. We examined dietary patterns in relation to nutrient intakes and adiposity in the National Heart, Lung, and Blood Institute Growth and Health Study cohort of 2371 black and white girls recruited at 9-10 y of age and followed for 10 y. Serial measurements were obtained for indices of anthropometry, dietary intake, physical activity, and sociodemographic variables. Dietary patterns for the 2 racial subgroups were separately identified by cluster analysis of 40 food groupings derived from 3-d food records. Nutrient intakes and measures of adiposity (BMI, percent body fat, and waist circumference) were compared by dietary pattern. We identified 4 discrete dietary patterns for black and for white adolescents. A Healthy pattern, followed by 12% of white girls and characterized by a high intake of fruits, vegetables, dairy, grains without added fats, mixed dishes and soups, and a low intake of sweetened drinks, other sweets, fried foods, burgers, and pizza, was related to more favorable nutrient intakes and a smaller increase in waist circumference. Among black girls, none of the dietary patterns appeared distinctly advantageous in terms of mitigating increases in adiposity. In conclusion, a cumulative pattern of food intake consistent with recommendations for general health appears to help prevent overweight, but this pattern was followed by only a minority of adolescent girls.

We investigate whether underweight, normal-weight, overweight, and obese Americans differ in their evaluations of positive and negative aspects of their interpersonal relationships. Analyses are based on data from the Midlife Development in the United States (MID US) study, a survey of more than 3,000 adults ages 25 to 74 in 1995. We find no significant differences across the body mass index (BMI) categories in the quality of relationships with friends, coworkers, and spouses. Severely obese persons report significantly higher levels of strain and lower levels of support in their family relationships. This pattern, however, is contingent upon one's adolescent body weight. Among persons who were of 'normal' weight at age 21, current BMI is not associated with relationship quality. For persons who were overweight at age 21, the level of social support received from family during adulthood declines as adult BMI increases. Implications for stigma theory are discussed.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.apergo.2005.01.012 Byline: Bing-Shiang Yang, James A. Ashton-Miller Abstract: A fall from a stepladder is often initiated by a loss of lateral stability. An inverted pendulum model of the human, validated by experiment, was used to determine the feasible range of whole-body center of mass (COM) states for which weight can be transferred laterally on a ladder tread without a ladder rail losing contact with the ground ('no lift-off' stability region). The results show that the size of the feasible no lift-off region was inversely proportional to the height of the tread above the ground, the distance of the stance foot from the ipsilateral rail, and lateral ground inclination angle. For given initial COM kinematics on a tread height equal to 40% human body height, a stance-foot location equal to one-eighth tread width and a 3.5[degrees] ground inclination had approximately equivalent effects on the no lift-off region size. Ladder stability was three times more sensitive to tread height than to foot location. Laterally-exerted impulsive hand-tool forces should generally be limited to 8% body weight. These findings can lead to improved ladder designs and safety instructions for stepladder users. Author Affiliation: Biomechanics Research Laboratory, Department of Mechanical Engineering, University of Michigan, 3216 G.G. Brown, 2250 Hayward Street, Ann Arbor, MI 48109-2125, USA

Objectives. We assessed changes in body mass index (BMI) among Brazilian adolescents. Methods. In 1975, 1989, and 1997, we conducted household surveys of the weights and statures of a probabilistic sample of about 50 000 Brazilian adolescents aged 10 to 19 years. Weighted prevalences were calculated and an analysis was performed with the sample design taken into account. Results. Adolescents of rich (southeast) and poor (northeast) regions showed a substantial increase in BMI. In the southeast, the prevalence of overweight, defined by international age- and gender-specific BMI cutoffs, for both genders reached 17% in 1997, whereas in the northeast, the prevalence tripled, reaching 5% among boys and 12% among girls. Older girls living in urban areas in the southeast showed a decrease in prevalence from 16% to 13% in the latter 2 surveys. For all boys and for young girls, the BMI values for the 85th percentile in 1997 were much higher than the 95th percentile values in 1975. Conclusions. BMI increased dramatically in Brazilian adolescents, mainly among boys; among older girls from the richest region, the prevalence of overweight is decreasing.

Background: Body mass index (BMI) or equivalent weight for height indices are the most widely used measures of body composition in early onset and adolescent eating disorders. Although of value as screening instruments the limitation in disease states is their inability to discriminate fat and fat-free components of body weight. Objective: To compare height-adjusted fat and fat-free components of body composition in children and young adolescents with different types of eating disorders with those of age matched reference children. Design: Weight, height, triceps and subscapular skinfold thickness were measured in 172 children (aged 7-16 y) with eating disorders receiving specialist treatment. Fat mass index (FMI) and fat-free mass index (FFMI) were calculated using Slaughter&apos;s and Deurenberg&apos;s equations and normalisation for height. Using data from 157 normal children, representative of the UK 1990 growth reference data, reference curves for FMI and FFMI [+ or -] 2 s.d. were derived. Results for patient groups were superimposed on these reference curves. Results: FMI and FFMI were both reduced in eating disorders associated with malnutrition, including anorexia nervosa (AN). AN subjects did not differ from other subjects with comparable degrees of malnutrition. Children with eating disorders of normal weight, such as bulimia nervosa and selective eating, did not differ significantly from reference children in their relative FM and FFM. Conclusions: FM and FFM merit independent consideration in disorders of malnutrition in children, rather than expressing data as percentage body fat or percentage BMI. The implications of loss of FFM on growth and development merit further investigation. doi:10.1038/sj.ejcn.1601403 Keywords: body composition; eating disorders; feeding disorders; anorexia nervosa; children; adolescents; fat mass; fat free mass, Introduction As well as defining the 'disease' state in eating disorders, nutritional status is highly correlated with mortality and morbidity, including osteoporosis (Treasure et al, 1986; Bachrach et al, 1990; [...]

The rapid physiological changes that occur during early adolescence are vulnerable to the effects of toxic substances, including alcohol. Studies show that alcohol consumption can delay puberty in female rats [...]

Preschool height-for-age is strongly related to adolescent height among rural adolescents aged 12 to 17 years old in Senegal, West Africa. An examination of preschool stunting on adolescent height and age at menarche among 1,657 children revealed a significant difference in the mean height during adolescence according to preschool height-for-age for both boys and girls. While the height deficit in their first years of life was not offset during late childhood or early adolescence, girls showed some catch-up growth during the second half of their teenage years.

Byline: Niklas Ravaja (1), Katri Raikkonen (1), Heikki Lyytinen (2), Terho Lehtimaki (3), Liisa Keltikangas-Jarvinen (1) Keywords: apolipoprotein E; behavioral genetics; cardiovascular responses; heart rate; mental stress Abstract: We investigated the relationship between apolipoprotein E (apoE) polymorphism and cardiovascular responses to experimentally induced mental stress. Mental stress was induced in 28 healthy 16-year-old boys with a series of stressors (e.g., mental arithmetic, Stroop Color-Word Interference Test). Heart rate (HR), finger blood volume, and skin conductance level were recorded continuously during the task performance. We found that boys with apoE3/2 or apoE3/3 showed marginally significantly greater HR reactivity and significantly greater task levels of HR and HR variability (HRV) during the mental stress than subjects with apoE4/2, apoE4/3, or apoE4/4. In addition, E4/2, E4/3, and E4/4 subjects manifested a distinct stress-related decrease in HRV relative to baseline values while E3/2 and E3/3 subjects showed a slight increase. The results suggests that apoE polymorphism is associated with cardiovascular responsivity to mental stress in adolescent boys. Author Affiliation: (1) Department of Psychology, University of Helsinki, Helsinki, Finland (2) Department of Psychology, University of Jyvaskyla, Jyvaskyla, Finland (3) Tampere University Hospital, Department of Clinical Chemistry and Medical School, University of Tampere, Tampere, Finland Article History: Registration Date: 09/09/2004

Slipped capital femoral epiphysis is sometimes painfully disabling but often children are active during an active slip. A complete hip examination is needed to rule out the epiphysis in the 10-15 years group with a thigh, knee and/or hip pain and no particular trauma history. The treatment stops the spread of the epiphysis and induces growth plate closure by open surgical procedures and in situ pinning of chronic and acute-on-chronic slipped capital femoral epiphysis enabling resumption of sports in 3 to 6 months.

Effects of supplementary feeding during early childhood on body size and composition at adolescence are examined in a population with marked growth failure in the first 3 y of life. The data came from a supplementation trial conducted in rural Guatemala from 1969 to 1977 and a 1988-89 follow-up study of the same subjects at adolescence. Two pairs of villages participated in the trial. One village from each pair received a high protein-energy supplement (Atole), which significantly improved dietary intakes, whereas the other village of the pair received a low-energy, no-protein supplement (Fresco), which did not impact appreciably on dietary intakes. Children from Atole villages grew better during the preschool period than children from Fresco villages. At adolescence, subjects from Atole villages were taller, weighed more and had greater fat-free masses than subjects from Fresco villages. Differences in height at adolescence were slightly reduced in magnitude relative to differences at 3 y of age. However, differences in weight were increased in adolescence relative to 3 y of age. INDEXING KEY WORDS: supplementation; growth; height; adolescence; rural Guatemala