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Building a Quantitative Evidence Base for Population Health Modelling to Address Childhood Overweight and Obesity
Abstracts / Can J Diabetes 37 (2013) S217eS289
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Assessing Determinants of Readiness to Change at Baseline in DECCO Cohort ANDREA MUCCI, L. HELDEN J. CHEN, O. SHACHAR, T MICHAEL VALLIS, KATHERINE M. MORRISON McMaster University, Hamilton, Ontario, Canada
Building a Quantitative Evidence Base for Population Health Modelling to Address Childhood Overweight and Obesity SUZANNE ROSS, RONALD WALL, CHRISTINA BANCEJ Health Policy Strategies, Hazelton, British Columbia, Canada
Objectives: To describe self-reported child and parent Readiness to Change (RTC) scores for lifestyle change at initiation of a weight management program; and to evaluate determinants of RTC scores at baseline. Methods: Youth (n¼269) aged 8e17 years and parents completed measures of RTC at enrolment into the program. RTC now and expected RTC 6 months from now were assessed in the parent and the child independently using Likert-style questions. The relationship between parent and child RTC and between RTC and age, extent of obesity, parental education, sex and family history of diabetes and heart disease were assessed by univariate, and for related variables, by multivariate regression analysis. Results: There was moderate correlation between parent and child RTC at baseline. However, parents reported a greater RTC than children for both the acute (8.25+1.25 vs 7.53+1.98) and long-term (7.73+1.56 vs 7.51+2.22). In univariate analysis, parental RTC for both acute and long-term were directly related to maternal education (p<0.001, p¼0.02), paternal education (p¼0.010, p¼0.015), and income (p¼0.015, p¼0.005), but were inversely related to parental diabetes history (p¼0.014, p¼0.042). In multivariate analysis, only maternal education predicted acute parental RTC. None of the determinants studied predicted child RTC. Conclusions: Assessing child and parent RTC at baseline may provide insight into motivation. RTC can be assessed using a simple scale. Parent and child RTC scores differed but were related. Parental education predicted increased RTC. The relationship of scores to progress in the weight management program must be evaluated to understand their clinical usefulness. 516-OR The Influence of Adiposity on Bone quality in Children, Adolescents and Young Adults CHRISTA HOY, HEATHER M. MACDONALD, HEATHER A. MCKAY Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada Overweight children have greater bone mass than their healthy weight peers; however, they sustain more fractures. Thus, there is a need to better understand the relation between body fat and bone quality. We aimed to determine the relationship between fat mass (FM, g) and aspects of bone quality (strength, geometry, density and microstructure) at the distal radius and distal tibia in boys (n¼137, 15.63.3 yrs) and girls (n¼157, 14.53.9 yrs) after adjusting for lean mass (LM, g). FM and LM were measured using dual energy X-ray absorptiometry and bone quality was measured using high resolution-peripheral QCT. In boys but not girls, FM negatively predicted bone strength (N) at the radius only. In both sexes, FM negatively predicted total area (mm2) at the radius only. In girls but not boys, FM positively predicted cortical bone mineral density (mgHA/cm3) at the tibia only. For bone microstructure, FM negatively predicted cortical thickness (mm) at the tibia in boys, trabecular thickness (mm) at the tibia in girls, and cortical porosity at both the radius and tibia in girls. In nearly all cases, LM mediated the relationship between FM and bone quality. Prior to adding LM to regression models FM positively predicted bone quality; however, after adjusting for LM the positive associations became non-significant or negative. The relation between fat and bone is complex and appears to be sex- and site-specific. The potentially hazardous influence of high levels of fat mass on youth bone health must be considered among the adverse consequences of overweight and obesity.
In 2010-11, Statistics Canada and the Public Health Agency of Canada (PHAC) collaborated to develop a dynamic Population HEalth Microsimulation model for Body Mass Index (POHEM-BMI) of the impact of BMI and health outcomes and costs averted for Canada to estimate the relative effectiveness (net health outcomes and costs avoided) of obesity interventions. To guide decisions to address trends in childhood obesity in Canada, PHAC required evidence of child interventions and quantitative estimates of their effect. This research report will introduce participants to POHEMBMI as an accessible planning tool for evidence-based policy on childhood obesity in Canada. It will also introduce participants to a project that aimed to compile a preliminary quantitative evidence base of interventions for addressing childhood obesity to be used to specify a set of alternative scenarios for POHEM-BMI, and to consider future needs for the application of POHEM-BMI as an accessible planning tool for evidence-based policy action. Evidence was prioritized to include intervention evidence reviews (vs. correlation research or single studies) with BMI as an outcome measure. A total of 14 study findings fell within five broad types of interventions: reducing food advertising to children (2), reducing screen time (3), school-based (4) and non-school-based (4) interventions to increase physical activity and healthy eating, and a school-based intervention to reduce consumption of carbonated drinks (1). Future needs for strengthening the capacity of the POHEM-BMI model to contribute to evidence-based policy relate to search strategies, reporting intervention characteristics, developing child population databases, and creating a POHEM-BMI user guide. 518-OR Effects on Resting Energy Expenditure, Aerobic and Musculoskeletal Fitness: The HEARTY Exercise Trial ANGELA ALBERGA, DENIS PRUD’HOMME, GLEN P. KENNY, GARY GOLDFIELD, STASIA HADJIYANNAKIS, REJEANNE GOUGEON, JANINE MALCOLM, JINHUI MA, RONALD J. SIGAL School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada Introduction: There is a need to test the effectiveness of lifestyle interventions to combat the epidemic of obesity in adolescents. We examined the effects of aerobic exercise, resistance exercise and their combination on resting energy expenditure (REE), aerobic and musculoskeletal fitness in obese adolescents in a randomized trial. Methods: Participants were inactive, overweight or obese adolescents (n¼304) aged 14-18 yr who volunteered for the HEARTY (Healthy Eating Aerobic and Resistance Training in Youth) trial. After a 4-week diet and exercise run-in, participants were randomized into 4 groups for 22 weeks: diet + aerobic exercise (A), diet + resistance exercise (R), diet + aerobic + resistance exercise (A+R), or diet-only control (C). All tests were conducted at baseline and after 6 months. REE and aerobic fitness (VO2peak) were tested using indirect calorimetry at rest and during a maximal treadmill test respectively. Musculoskeletal fitness was assessed using CSEP-CPAFLA protocols for grip strength, push-up, sit & reach, curl-up and vertical jump tests. Results: VO2peak increased significantly in A (30.6 0.6 to 33.4 0.7 mlO2/kg/min, p¼0.002 vs. C and p¼0.026 vs. R) and nonsignificantly in A+R (30.6 0.6 to 32.2 0.6 mlO2/kg/min, p¼0.076 vs. C). There were significant (p<0.05) within-group improvements in maximal treadmill workload and abdominal curl-ups in all 3 exercise groups but not in C. Changes in REE did not differ among groups. Discussion: Only aerobic training increased peak oxygen consumption. Aerobic, resistance or combined exercise increased abdominal muscular endurance but not resting energy expenditure in obese adolescents.
S225
515-OR
517-OR
Assessing Determinants of Readiness to Change at Baseline in DECCO Cohort ANDREA MUCCI, L. HELDEN J. CHEN, O. SHACHAR, T MICHAEL VALLIS, KATHERINE M. MORRISON McMaster University, Hamilton, Ontario, Canada
Building a Quantitative Evidence Base for Population Health Modelling to Address Childhood Overweight and Obesity SUZANNE ROSS, RONALD WALL, CHRISTINA BANCEJ Health Policy Strategies, Hazelton, British Columbia, Canada
Objectives: To describe self-reported child and parent Readiness to Change (RTC) scores for lifestyle change at initiation of a weight management program; and to evaluate determinants of RTC scores at baseline. Methods: Youth (n¼269) aged 8e17 years and parents completed measures of RTC at enrolment into the program. RTC now and expected RTC 6 months from now were assessed in the parent and the child independently using Likert-style questions. The relationship between parent and child RTC and between RTC and age, extent of obesity, parental education, sex and family history of diabetes and heart disease were assessed by univariate, and for related variables, by multivariate regression analysis. Results: There was moderate correlation between parent and child RTC at baseline. However, parents reported a greater RTC than children for both the acute (8.25+1.25 vs 7.53+1.98) and long-term (7.73+1.56 vs 7.51+2.22). In univariate analysis, parental RTC for both acute and long-term were directly related to maternal education (p<0.001, p¼0.02), paternal education (p¼0.010, p¼0.015), and income (p¼0.015, p¼0.005), but were inversely related to parental diabetes history (p¼0.014, p¼0.042). In multivariate analysis, only maternal education predicted acute parental RTC. None of the determinants studied predicted child RTC. Conclusions: Assessing child and parent RTC at baseline may provide insight into motivation. RTC can be assessed using a simple scale. Parent and child RTC scores differed but were related. Parental education predicted increased RTC. The relationship of scores to progress in the weight management program must be evaluated to understand their clinical usefulness. 516-OR The Influence of Adiposity on Bone quality in Children, Adolescents and Young Adults CHRISTA HOY, HEATHER M. MACDONALD, HEATHER A. MCKAY Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada Overweight children have greater bone mass than their healthy weight peers; however, they sustain more fractures. Thus, there is a need to better understand the relation between body fat and bone quality. We aimed to determine the relationship between fat mass (FM, g) and aspects of bone quality (strength, geometry, density and microstructure) at the distal radius and distal tibia in boys (n¼137, 15.63.3 yrs) and girls (n¼157, 14.53.9 yrs) after adjusting for lean mass (LM, g). FM and LM were measured using dual energy X-ray absorptiometry and bone quality was measured using high resolution-peripheral QCT. In boys but not girls, FM negatively predicted bone strength (N) at the radius only. In both sexes, FM negatively predicted total area (mm2) at the radius only. In girls but not boys, FM positively predicted cortical bone mineral density (mgHA/cm3) at the tibia only. For bone microstructure, FM negatively predicted cortical thickness (mm) at the tibia in boys, trabecular thickness (mm) at the tibia in girls, and cortical porosity at both the radius and tibia in girls. In nearly all cases, LM mediated the relationship between FM and bone quality. Prior to adding LM to regression models FM positively predicted bone quality; however, after adjusting for LM the positive associations became non-significant or negative. The relation between fat and bone is complex and appears to be sex- and site-specific. The potentially hazardous influence of high levels of fat mass on youth bone health must be considered among the adverse consequences of overweight and obesity.
In 2010-11, Statistics Canada and the Public Health Agency of Canada (PHAC) collaborated to develop a dynamic Population HEalth Microsimulation model for Body Mass Index (POHEM-BMI) of the impact of BMI and health outcomes and costs averted for Canada to estimate the relative effectiveness (net health outcomes and costs avoided) of obesity interventions. To guide decisions to address trends in childhood obesity in Canada, PHAC required evidence of child interventions and quantitative estimates of their effect. This research report will introduce participants to POHEMBMI as an accessible planning tool for evidence-based policy on childhood obesity in Canada. It will also introduce participants to a project that aimed to compile a preliminary quantitative evidence base of interventions for addressing childhood obesity to be used to specify a set of alternative scenarios for POHEM-BMI, and to consider future needs for the application of POHEM-BMI as an accessible planning tool for evidence-based policy action. Evidence was prioritized to include intervention evidence reviews (vs. correlation research or single studies) with BMI as an outcome measure. A total of 14 study findings fell within five broad types of interventions: reducing food advertising to children (2), reducing screen time (3), school-based (4) and non-school-based (4) interventions to increase physical activity and healthy eating, and a school-based intervention to reduce consumption of carbonated drinks (1). Future needs for strengthening the capacity of the POHEM-BMI model to contribute to evidence-based policy relate to search strategies, reporting intervention characteristics, developing child population databases, and creating a POHEM-BMI user guide. 518-OR Effects on Resting Energy Expenditure, Aerobic and Musculoskeletal Fitness: The HEARTY Exercise Trial ANGELA ALBERGA, DENIS PRUD’HOMME, GLEN P. KENNY, GARY GOLDFIELD, STASIA HADJIYANNAKIS, REJEANNE GOUGEON, JANINE MALCOLM, JINHUI MA, RONALD J. SIGAL School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada Introduction: There is a need to test the effectiveness of lifestyle interventions to combat the epidemic of obesity in adolescents. We examined the effects of aerobic exercise, resistance exercise and their combination on resting energy expenditure (REE), aerobic and musculoskeletal fitness in obese adolescents in a randomized trial. Methods: Participants were inactive, overweight or obese adolescents (n¼304) aged 14-18 yr who volunteered for the HEARTY (Healthy Eating Aerobic and Resistance Training in Youth) trial. After a 4-week diet and exercise run-in, participants were randomized into 4 groups for 22 weeks: diet + aerobic exercise (A), diet + resistance exercise (R), diet + aerobic + resistance exercise (A+R), or diet-only control (C). All tests were conducted at baseline and after 6 months. REE and aerobic fitness (VO2peak) were tested using indirect calorimetry at rest and during a maximal treadmill test respectively. Musculoskeletal fitness was assessed using CSEP-CPAFLA protocols for grip strength, push-up, sit & reach, curl-up and vertical jump tests. Results: VO2peak increased significantly in A (30.6 0.6 to 33.4 0.7 mlO2/kg/min, p¼0.002 vs. C and p¼0.026 vs. R) and nonsignificantly in A+R (30.6 0.6 to 32.2 0.6 mlO2/kg/min, p¼0.076 vs. C). There were significant (p<0.05) within-group improvements in maximal treadmill workload and abdominal curl-ups in all 3 exercise groups but not in C. Changes in REE did not differ among groups. Discussion: Only aerobic training increased peak oxygen consumption. Aerobic, resistance or combined exercise increased abdominal muscular endurance but not resting energy expenditure in obese adolescents.