No abstract

pDCD is associated with higher body mass and waist circumference, both important risk factors for cardiovascular disease, type 2 diabetes, and psychological problems and other health conditions.

This study examines the associations among socioeconomic status (SES), aging, gender and sport and physical activity participation from late childhood into adolescence. Drawing from previous research, we test three hypotheses regarding the impact of aging on SES and sport participation using longitudinal data. The data come from a prospective cohort study of children, all of whom were enrolled in grade 4 (at baseline) in the public school system of a large region of southern Ontario, Canada. We examine two outcome measures: participation in organized sport and physical activity and active free play. Our results show different effects of neighborhood household income, aging and gender for each outcome. For organized sport participation, neighborhood household income effects are constant over time for both boys and girls. For active free play however, neighborhood household income differences widen (or diverge) over time for girls, but not for boys. We discuss the implications of these findings for future research and policy considerations.Cette étude examine les associations entre statut socioéconomique, âge, genre et participation en sport et en activité physique de la fin de l’enfance à l’adolescence. Nous nous appuyons sur les recherches antérieures et des données longitudinales pour tester trois hypothèses à propos de l’impact de l’âge sur le statut socioéconomique et la participation en sport. Les données proviennent d’une étude de cohorte prospective d’enfants, tous étant inscrits en 4ème année (au début de l’étude) dans le système scolaire public d’une grande région du sud de l’Ontario au Canada. Nous mesurons deux types de résultats : la participation en sport organisé et activité physique et le jeu libre actif. Nos résultats montrent différents effets du revenu du ménage du quartier, de l’âge et du genre pour chaque résultat. Pour la participation en sport organisé, les effets du revenu du ménage du quartier sont constants avec le temps à la fois pour les garçons et les filles. Pour le jeu libre actif en revanche, les différences dans le revenu du ménage augmentent (ou divergent) avec le temps pour les filles, mais pas pour les garçons. Nous discutons les implications de ces résultats pour les études et politiques futures.

verweight and obesity (OW/OB) are pandemic. The accelerated increase of OW/OB in children and adolescents is alarming as several studies suggested that approximately 80% of childhood OW/OB tracks into adulthood. 1,2 In 1978, approximately 15% of the Canadian population between ages 2 to 17 years were considered OW/OB; in 2005, that figure was nearly doubled. 3 Unlike mortality or life expectancy, for which there is a clear disadvantage for those with lower income, the relationship between income and obesity is not clear. 4 This suggests that OW/OB affects the entire population. As OW/OB in adults is a wellknown risk factor for a number of chronic diseases including cardiovascular disease, type 2 diabetes and certain cancers, [5][6][7] there is a clear need to address the development of obesity in childhood. The root cause of OW/OB is an imbalance between energy intake and expenditure, but the underlying causes of OW/OB are much more complex and numerous. Environmental, behavioural, social, cultural and genetic factors all contribute to its development. [8][9][10] Emerging evidence suggests that sleep may play a role in the development of OW/OB. A number of studies have identified a negative association between the duration of sleep and the risk of obesity in both child and adult populations. [11][12][13] However, research in the area of sleep behaviours and the risk of obesity is limited. Therefore, in this study, as part of an ongoing cohort study conducted in southern Ontario, Canada, we examined whether sleep difficulties, as reported by parents and reflected by certain sleep behaviours, are associated with OW/OB status among a preadolescent population. METHODSData are from the PHAST (Physical Health Activity Study Team) study conducted among preadolescents in Niagara Region. This study has been reviewed and approved by the Ethics Research Boards of both Brock University and District School Board of Niagara (DSBN). There are a total of 97 public schools within DSBN. In 2004, approximately 2,200 students in grade four, aged 8-9 years, from 75 schools were involved in a longitudinal cohort study to examine the relationship between developmental coordination disorder and its risk factors. 14 The students' height, weight and waist girth were assessed biannually for the first three years and annually thereafter. Height and weight were measured using a Seca portable stadiometer and Tanita electronic weight scale, respectively. Waist girth was measured using standard protocols. Height and waist girth were measured to 0.1 cm and weight was measured to 0.1 kg. Weight and height were used to calculate body mass index (BMI). Students were categorized into either OW/OB or nor-