Publications

The purpose of this study was to assess the criterion validity of existing accelerometer-based energy expenditure (EE) prediction equations among children with chronic conditions, and to develop new prediction equations. Children with congenital heart disease (CHD), cystic fibrosis (CF), dermatomyositis (JDM), juvenile arthritis (JA), inherited muscle disease (IMD), and hemophilia (HE) completed 7 tasks while EE was measured using indirect calorimetry with counts determined by accelerometer. Agreement between predicted EE and measured EE was assessed. Disease-specific equations and cut points were developed and cross-validated. In total, 196 subjects participated. One participant dropped out before testing due to time constraints, while 15 CHD, 32 CF, 31 JDM, 31 JA, 30 IMD, 28 HE, and 29 healthy controls completed the study. Agreement between predicted and measured EE varied across disease group and ranged from (ICC) .13-.46. Disease-specific prediction equations exhibited a range of results (ICC .62-.88) (SE 0.45-0.78). In conclusion, poor agreement was demonstrated using current prediction equations in children with chronic conditions. Disease-specific equations and cut points were developed.

We investigated whether the relationships between BMI, waist circumference (WC), and sum of 5 skinfolds (S5S) have changed over time in Canadians. Anthropometric data on 7-69 year old from national representative surveys conducted in 1981 (n = 15,688) and 2007-2009 (n = 4,987) were examined. WC and S5S were regressed on BMI while controlling for age in each survey by sex and age group (child, adult). The results indicate that increases in WC and SFS for a one unit increase in BMI were higher in 2007-2009 than in 1981. For example, in 20-69 year old women in 1981 an increase in BMI of 1 kg/m(2) was associated with corresponding increases of 1.98 cm in WC and 6.10 mm in SFS; these values increased to 2.22 cm and 7.60 mm, respectively, in 2007-2009. In conclusion, present day Canadians have higher WC and skinfold thickness values for a given BMI than Canadians did 30 years ago.

No abstract is provided for this article.

No abstract is provided for this article.

New evidence-based physical activity and sedentary behavior guidelines for Canadians were launched in 2011. As a consequence, service organizations that promote physical activity directly to the public needed to change their promotion materials to reflect the new guidelines. Little is known about the rate at which service organizations adopt and integrate new evidence-based guidelines and determinants of guideline adoption. In this natural observational study, we evaluated the rate of online adoption of the new guidelines among key service organizations that promote physical activity and examined participation in a booster webinar as a supplemental dissemination strategy. One hundred fifty nine service organization websites were coded by one of six raters prior to the release of the new guidelines as well as at 3, 6, and 9 months after the release. Online adoption of the guidelines increased during the coding period with 51 % of organizations posting the guidelines or related information on their websites. Organizations' engagement in a webinar was associated with their adoption of the guidelines. The release of new Canadian Physical Activity and Sedentary Behaviour Guidelines led to increased guideline adoption on service organizations' websites. However, adoption was not universal. In order for the uptake of the new guidelines to be successful, further efforts need to be taken to ensure that service organizations present physical activity guidelines on their websites. Comprehensive, active dissemination strategies tailored to address organizational barriers are needed to ensure online guideline adoption.

Introduction Rest until symptom-free, followed by a progressive stepwise return to activities, is often prescribed in the management of paediatric concussions. Recent evidence suggests prolonged rest may hinder recovery, and early resumption of physical activity may be associated with more rapid recovery postconcussion. The primary objective is to determine whether the early reintroduction of non-contact physical activity beginning 72 hours postinjury reduces postconcussive symptoms at 2 weeks in children following an acute concussion as compared with a rest until asymptomatic protocol. Methods and analysis This study is a randomised clinical trial across three Canadian academic paediatric emergency departments. A total of 350 participants, aged 10–17.99 years, who present within 48 hours of an acute concussion, will be recruited and randomly assigned to either the study intervention protocol (resumption of physical activity 72 hours postconcussion even if experiencing symptoms) or physical rest until fully asymptomatic. Participants will document their daily physical and cognitive activities. Follow-up questionnaires will be completed at 1, 2 and 4 weeks postinjury. Compliance with the intervention will be measured using an accelerometer (24 hours/day for 14 days). Symptoms will be measured using the validated Health and Behaviour Inventory. A linear multivariable model, adjusting for site and prognostically important covariates, will be tested to determine differences between groups. The proposed protocol adheres to the RCT-CONSORT guidelines. Discussion This trial will determine if early resumption of non-contact physical activity following concussion reduces the burden of concussion and will provide healthcare professionals with the evidence by which to recommend the best timing of reintroducing physical activities. Trial registration number Trial identifier (Clinicaltrials.gov) NCT02893969 .

Studies based on adolescents and adults have found that the use of self-reported height and weight to calculate body mass index (BMI) yields a lower prevalence of obesity than do estimates based on measured data. Relatively few studies have examined the bias resulting from the use of parent-reported height and weight for children, and the findings have been inconsistent.Data are from the 2007 to 2009 Canadian Health Measures Survey. Parent-reported height and weight of children aged 6 to 11 (n=854) were obtained. Subsequently, the children's height and weight were directly measured.On average, parents underestimated the height (3.3 cm) and weight (1.1 kg) of their children. Estimates of the prevalence of obesity were significantly higher when based on parent-reported versus measured values for children aged 6 to 8; the two collection methods yielded similar estimates of obesity for children aged 9 to 11. For children in both age groups, misclassification errors for BMI categories were substantial when based on parent-reported values. This weakened associations between obesity and health indicators such as aerobic fitness and systolic blood pressure. The variance explained by factors associated with the bias in parent-reported height and weight was small, particularly for height. The use of correction equations based on variables associated with the bias resulted in a very modest reduction in misclassification errors.Bias associated with parental reports of children's height and weight results in misclassification errors for obesity that affect relationships with other variables. Efforts to establish correction equations to adjust for this bias were unsuccessful. Direct measures are required to accurately calculate obesity estimates and their relationships with health indicators in children.

Patients with traumatic brain injury (TBI) are characterized by premature fatigue that may be related to their low aerobic capacity and reduced cortical activation. Near infrared spectroscopy (NIRS) is a valid, noninvasive technique for determining cerebral oxygenation (Cox) and blood volume (Cbv) during exercise. An increase in Cox and Cbv measured by NIRS is reflective of increased cortical activation. PURPOSE: To examine the inter-relationships among the peak values of the power output, oxygen uptake (peak VO2), Cox and Cbv during incremental cycle exercise to voluntary fatigue in patients with TBI. METHODS: Twenty-one inpatients (17 males, 4 females) with TBI from a rehabilitation center consented to perform a symptom limited incremental exercise test to voluntary fatigue. Cardiorespiratory responses were continuously monitored using an automated metabolic measurement cart (Vmax, Sensormedics, CA) interfaced with an electro-cardiogram. NIRS was used to continuosuly record Cox and Cbv from both the frontal lobes using a dual wave-length instrument (MicroRunman, NIM Inc., PA). Data were averaged over 20 sec intervals for statistical analysis. RESULTS: Regression analysis indicated that oxygen uptake and heart rate increased linearly with work rate while Cox and Cbv increased in a curvilinear manner. Patients attained a peak heart rate that corresponded to 76% of their age predicted maximum heart rate (220 - age), indicating an inability to fully tax their cardiovascular system. The peak values of power (86.4 ± 59.4 Watts), VO2 (20.5 ± 8.1 ml/kg/min) and O2 pulse (11.0 ± 5.3 ml/beat) were considerably lower than those reported for healthy individuals matched for age and gender. A significant (P < .05) relationship was observed between peak power vs absolute peak VO2 (r = 0.76) and relative peak VO2 (r = 0.72). In general, stronger correlations were observed between the hemodynamic variables on the left side and the peak power and peak oxygen uptake as compared to the right side. However, only Cbv on the left side was significantly related to the peak power output (r = 0.51), absolute peak VO2 (r = 0.61) and relative peak VO2 (r = 0.54). CONCLUSIONS: These findings suggest that changes in cerebral blood volume in the left frontal lobe may play an important role in determining the peak exercise capacity in patients with TBI. Support: Alberta Heritage Foundation for Medical

No abstract is provided for this article.

No abstract is provided for this article.

Objectives: Excessive recreational screen time (RST) is associated with detrimental effects for physical, psychological and cognitive development. This article aims to describe the prevalence of excessive RST among Colombian preschoolers, children and adolescents and explore its factors associated. Methods: We analyzed data from the National Survey of Nutrition 2015. The sample included 4,503 preschoolers, 5,333 school-aged children and 6,623 adolescents. Poisson regression models with robust variance were conducted to estimate prevalence ratios and determine associated factors of excessive RST. Results: Fifty percent of preschoolers, 61% of school-aged children and 73% of adolescents in Colombia had excessive RST. Positive associations were observed with the availability of TV in the child’s bedroom, the availability of video games at home, and eating while using screens. A negative association with rural area was observed for all age groups. Conclusion: The majority of Colombian children and adolescents have excessive RST. Younger preschoolers, older school-aged children, wealthiest children and those from urban areas should be targeted by interventions to decrease RST. These interventions should promote limiting the availability of electronic devices in children’s bedrooms and not eating in front of screens.

No abstract is provided for this article.