Investigation of Underlying Association between Anthropometric and Cardiorespiratory Fitness Markers among Overweight and Obese Adolescents in Canada.

BACKGROUND: Adolescents who experience overweight or obesity commonly persist in these conditions into adulthood, thereby elevating their vulnerability to health issues. The focus of this study is on health risk markers such as body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), body surface area (BSA), and cardiorespiratory fitness (CRF). The objectives include updating normative values for BMI, WC, WHtR, and BSA in Canadian adolescents, establishing cardiometabolic risk zones, and developing a composite score considering both anthropometric and CRF markers. METHODS: Involving 1864 adolescents, the study used the LMS method to generate percentile norms, stratified by age and sex. Cardiometabolic risk zones were established for each marker based on Z-scores, and a composite score was created. RESULTS: An increase in WC of 5.8 and 7.4 cm for boys and girls, respectively, was observed since 1981. Forward multiple regression analyses were conducted to assess the robustness and validity of the proposed model. The results indicated that the model explained nearly 90% (R2 = 0.890) of the common variance between the composite score and the retained independent variables. Moreover, the model demonstrated a mean absolute error (MAE) of approximately 6 percentiles, confirming its high precision. Furthermore, these analyses yielded key thresholds for identifying adolescents at risk: the 70th percentile for high cardiometabolic risk and the 85th percentile for very-high risk. CONCLUSIONS: Individually, WC or WHtR seem to be better markers for evaluating cardiometabolic risk than BMI during adolescence. However, CRF showed comparable importance to anthropometric markers in determining cardiometabolic risk. The simultaneous inclusion of anthropometric and CRF markers provides a better picture of the global cardiometabolic risk in adolescents.

Updating normative cross-sectional values and secular trends in body mass, body height and body mass index among Québec children and adolescents.

OBJECTIVE: The main objective of this study was to examine secular trends in body mass, body height and body mass index (BMI) from measured rather than self-reported values between 1972 and 2017. METHODS: A total of 4500 students (males = 51%) were selected from a stratified sampling. The age range varied between 6.0 and 17.9 years. The sample came from 24 elementary schools and 12 high schools located in six urban cities from the province of Québec. All the tests selected were based on standardized procedures that are recognized as valid and reliable. Standardization and modeling of smoothed percentile curves for each variable for both sexes were produced. RESULTS: Regional variations between youth from the province of Québec and those from all other Canadian provinces confirm the relevance of using data specific to the target population. Comparisons with the 1972 and 1982 data show an important increase in body mass (~ 7 kg, i.e. 16.4%) and BMI (~ 1.4 kg·m-2, i.e. 19.9%) with minor change in body height (~ 1.8 cm, i.e. 3.9%). Youth from low-income backgrounds (p = 0.001) as well as those living in large urban cities (p = 0.002) see their probability of developing overweight or obesity greatly increase (low-income = 2.1 times; large urban cities = 1.3 times). However, overweight and obesity rates seem to have stabilized at around 21% since 2004. CONCLUSION: This study provides up-to-date data on factors that contribute to the prevalence of overweight and obesity in youth in urban settings of Québec, and will be instrumental in guiding public health strategies designed to optimize growth outcomes.

RéSUMé: OBJECTIF: L'objectif principal de cette étude était d'examiner les tendances séculaires de la masse corporelle, de la taille et de l'indice de masse corporelle (IMC) de 1972 à 2017 à partir de valeurs mesurées plutôt que de valeurs autodéclarées. MéTHODE: Un total de 4 500 étudiants (garçons = 51 %) ont été sélectionnés à partir d'un échantillon stratifié. La fourchette d'âge variait entre 6,0 et 17,9 ans. L'échantillon provenait de 24 écoles primaires et 12 écoles secondaires situées dans six villes de la province de Québec (Canada). Tous les tests sélectionnés reposaient sur des procédures standardisées, reconnues comme valides et fidèles. Une standardisation et une modélisation des courbes centiles lissées ont été produites pour chaque variable pour les deux sexes. RéSULTATS: Les variations régionales entre les jeunes du Québec et ceux du reste du Canada confirment la pertinence d'utiliser des données spécifiques à la population cible. Les comparaisons entre les données de 1972 et de 1982 montrent une augmentation importante de la masse corporelle et de l'IMC (p ≤ 0,05) sans changement important de la taille corporelle. Les jeunes issus de milieux à faibles revenus (p = 0,001) ainsi que ceux vivant dans les grandes villes (p = 0,002) voient leurs risques de développer un surpoids ou de l'obésité augmenter considérablement (faibles revenus = 2,1 fois; grandes villes urbaines = 1,3 fois). Toutefois, les taux de surpoids et d'obésité semblent s'être stabilisés autour de 21 % depuis 2004. CONCLUSION: Cette étude fournit des données à jour sur les facteurs qui contribuent à la prévalence de l'embonpoint et de l'obésité chez les jeunes des milieux urbains du Québec et contribuera à orienter les stratégies de santé publique afin d'optimiser le suivi sur la croissance physique des jeunes.

Discriminant analysis of anthropometric and biomotor variables among elite adolescent female athletes in four sports.

The aim of this study was to identify anthropometric and biomotor variables that discriminated among groups of elite adolescent female athletes aged 14.3 +/- 1.3 years (mean +/- s) from four different sports (tennis, n = 15; swimming, n = 23; figure skating, n = 46; volleyball, n = 16). The anthropometric variables included body mass, height, bi-epicondylar breadth of the distal extremity of the humerus and femur, maximal girth of the calf and biceps and the sum of five adipose skinfolds. The biomotor variables were maximal aerobic power, muscular endurance and flexibility of the trunk. Discriminant analysis revealed three significant functions (P < 0. 05). The first discriminant function primarily represented differences between figure skaters and all other groups of athletes. The other two underlined anthropometric and biomotor differences between swimmers and volleyball players and between tennis players and swimmers, respectively. After validation, the analysis showed that 88% of the athletes were correctly classified in their respective sports. Our model confirms that elite adolescent female athletes show physical and biomotor differences that clearly distinguish them according to their particular sport.