Role of Physical Activity and Sedentary Behaviors on Vascular and Myocardial Structure and Function in Type 1 Diabetes.

OBJECTIVE: To estimate associations between physical activity and sedentary behaviors and early markers of cardiovascular diseases in adolescents with and without type 1 diabetes. STUDY DESIGN: Cross-sectional data stem from the CARdiovascular Disease risk in pEdiatric type 1 diAbetes (CARDEA) study, a study investigating early cardiovascular disease development in 100 adolescents with type 1 diabetes recruited at Sainte-Justine University Hospital Diabetes Clinic and 97 healthy adolescents without diabetes (14-18 years), in Montreal, Canada. Outcomes included arterial stiffness by pulse-wave velocity, endothelial function (velocity time integral) by flow-mediated dilation test, and cardiac magnetic resonance imaging markers. Moderate-to-vigorous physical activity (MVPA) and sedentary time were estimated by accelerometry and leisure screen time by questionnaire. We estimated multivariable linear regression models stratified by group. RESULTS: In adolescents with type 1 diabetes, 10-minutes daily increase in MVPA was associated with 3.69 g/m (95% CI: -1.16; 8.54) higher left ventricular (LV) mass/height and 1-hour increase in device-measured sedentary time with 0.68 mm (0.20; 1.16) higher wall thickness but only in those with glycated hemoglobin ≤7.5%. In healthy adolescents, a 10-minute increase in MVPA was associated with 1.32 g/m (-0.03; 2.66) higher LV mass/height. Every 1-hour increase in sedentary time was associated with -1.82 cm (-3.25; -0.39) lower velocity time integral, -2.99 g/m (-5.03; -0.95) lower LV mass/height, and -0.47 mm (-0.82; -0.12) lower wall thickness. CONCLUSIONS: Being active and limiting sedentary time appears beneficial for cardiac structure and endothelial function in healthy adolescents; however, adequate glycemic control combined with higher levels of MVPA may be required for adolescents with type 1 diabetes to overcome the impact of diabetes.

Family systems approaches in pediatric obesity management: a scoping review.

Family-based obesity management interventions targeting child, adolescent and parental lifestyle behaviour modifications have shown promising results. Further intervening on the family system may lead to greater improvements in obesity management outcomes due to the broader focus on family patterns and dynamics that shape behaviours and health. This review aimed to summarize the scope of pediatric obesity management interventions informed by family systems theory (FST). Medline, Embase, CINAHL and PsycInfo were searched for articles where FST was used to inform pediatric obesity management interventions published from January 1980 to October 2023. After removal of duplicates, 6053 records were screened to determine eligibility. Data were extracted from 50 articles which met inclusion criteria; these described 27 unique FST-informed interventions. Most interventions targeted adolescents (44%), were delivered in outpatient hospital settings (37%), and were delivered in person (81%) using group session modalities (44%). Professionals most often involved were dieticians and nutritionists (48%). We identified 11 FST-related concepts that guided intervention components, including parenting skills, family communication, and social/family support. Among included studies, 33 reported intervention effects on at least one outcome, including body mass index (BMI) (n = 24), lifestyle behaviours (physical activity, diet, and sedentary behaviours) (n = 18), mental health (n = 12), FST-related outcomes (n = 10), and other outcomes (e.g., adiposity, cardiometabolic health) (n = 18). BMI generally improved following interventions, however studies relied on a variety of comparison groups to evaluate intervention effects. This scoping review synthesises the characteristics and breadth of existing FST-informed pediatric obesity management interventions and provides considerations for future practice and research.

The longitudinal effects of maternal parenting practices on children's body mass index z-scores are lagged and differential.

BACKGROUND: The longitudinal relation between parenting practices and styles with children's body mass index z-scores (zBMI) is poorly understood. Previous studies suggest the relationship may be complex, but small samples and short follow-ups diminish the strength of the evidence. The objectives of this study were to investigate whether the relationship is bidirectional, time-varying, and lagged using data from a large, representative birth cohort of Quebec children. METHODS: Data were from the Québec Longitudinal Study of Child Development (QLSCD), a prospective birth cohort (n = 1,602). The mothers' interactions with their children (at ages 6, 8, 10, and 12 years) were utilized in factor analysis to identify three latent parenting practices (disciplinarian, lenient, and responsive). The parenting practices were analyzed with K-means clustering to identify the parenting styles. The temporal and bidirectional relationships were assessed in a cross-lagged path analysis using a structural equation modelling framework. Mixed models controlling for age, sex, income, mother's education, and whether the participant was first-born were estimated. Missing data were handled with full information maximum likelihood. RESULTS: From the linear mixed models, greater lenient and responsive parenting practices were associated with higher zBMI (B = 0.03, p < 0.05) two years later. However, there was no evidence that the relationship was bidirectional nor that parenting style was predictive of children's zBMI. CONCLUSION: While mothers' parenting practices were unaffected by their children's zBMI, parental practices were predictive of future zBMI among their prepubertal children. More in-depth exploration of parenting practices and their potential impact on pediatric weight is needed.

Associations between family functioning during early to mid-childhood and weight status in childhood and adolescence: findings from a Quebec birth cohort.

BACKGROUND: Impaired family functioning has been associated with obesity in children and adolescents, but few longitudinal studies exist. We examined whether family functioning from early to mid-childhood is associated with overweight and obesity in later childhood and adolescence. METHODS: We examined data from the Quebec Longitudinal Study of Child Development (QLSCD), a birth cohort (N = 2120), collected between 1998 and 2011. Parent-reported family functioning was assessed at 4 time points between ages 0.5 and 8 years using the McMaster Family Assessment Device with established cut-offs for impaired family functioning. Participants were classified as having experienced: 1) early-childhood impaired functioning, 2) mid-childhood impaired functioning, 3) both early and mid-childhood impaired functioning, or 4) always healthy family functioning. Overweight and obesity were determined at 10- and 13-years using WHO criteria. Covariate adjusted multinomial logistic regressions were fitted to the data to examine associations between longitudinal family functioning groups (using the always healthy functioning as reference category) and the likelihood of having overweight and obesity (vs normal weight) at ages 10 (n = 1251) and 13 years (n = 1226). RESULTS: In the 10- and 13-year sub-samples, respectively 10.2% and 12.5% of participants had experienced both early and mid-childhood impaired family functioning. Participants in this group had an increased likelihood of having obesity (vs normal weight) at age 10 years [OR = 2.63 (95% CI: 1.36; 5.08)] and at age 13 years [OR = 1.94 (95% CI: 0.99; 3.80] compared to those in the always healthy functioning group. No associations were found for other family functioning categories or for overweight status. CONCLUSION: Approximately one in ten children experienced impaired family functioning throughout early and mid-childhood. Findings suggest a link between impaired functioning across childhood and the development of obesity at 10 years of age and possibly at 13 years of age.

Neighborhood built environment typologies and adiposity in children and adolescents.

BACKGROUND/OBJECTIVES: Neighborhoods are complex, multidimensional systems. However, the interrelation between multiple neighborhood dimensions is seldom considered in relation to youth adiposity. We created a neighborhood typology using a range of built environment features and examined its association with adiposity in youth. SUBJECTS/METHODS: Analyses are based on data from the QUALITY cohort, an ongoing study on the natural history of obesity in Quebec youth with a history of parental obesity. Adiposity was measured at baseline (8-10 years) and follow up, ~8 years later. Neighborhood features were measured at baseline through in-person neighborhood assessments and geocoded administrative data and were summarized using principal components analysis. Neighborhood types were identified using cluster analysis. Associations between neighborhood types and adiposity were examined using multivariable linear regressions. RESULTS: Five distinct neighborhood types characterized by levels of walkability and traffic-related safety were identified. At ages 8-10 years, children in moderate walkability/low safety neighborhoods had higher BMI Z-scores [ß: 0.41 (0.12; 0.71), p = 0.007], fat mass index [ß: 1.22 (0.29; 2.16), p = 0.010], waist circumference [ß: 4.92 (1.63; 8.21), p = 0.003], and central fat mass percentage [ß: 1.60 (0.04; 3.16), p = 0.045] than those residing in moderate walkability/high safety neighborhoods. Attenuated associations were observed between neighborhood types and adiposity 8 years later. Specifically, residents of moderate walkability/low safety neighborhoods had a higher FMI [ß: 1.42 (-0.07; 2.90), p = 0.062], and waist circumference [ß: 5.04 (-0.26; 10.34), p = 0.062]. CONCLUSIONS: Neighborhoods characterized by lower traffic safety appear to be the most obesogenic to children, regardless of other walkability-related features. Policies targeting neighborhood walkability for children may need to prioritize vehicular traffic safety.

Natural history and determinants of dysglycemia in Canadian children with parental obesity from ages 8-10 to 15-17 years: The QUALITY cohort.

In children, the mechanisms implicated in deterioration of glucose homeostasis versus reversion to normal glucose tolerance (NGT) remain uncertain. We aimed to describe the natural history of dysglycemia from childhood to late adolescence and to identify its early determinants. We used baseline (8-10 years, n = 630), 1st follow-up (10-12 years, n = 564) and 2nd follow-up (15-17 years, n = 377) data from the QUALITY cohort of White Canadian children with parental obesity. Children underwent a 2-h oral glucose tolerance test at each cycle with plasma glucose and insulin measured at 0/30/60/90/120 min. American Diabetes Association criteria defined dysglycemia (impaired fasting glucose, impaired glucose tolerance or type 2 diabetes). Longitudinal patterns of insulin sensitivity and beta-cell function were estimated using generalized additive mixed models. Model averaging identified biological, sociodemographic and lifestyle-related determinants of dysglycemia. Of the children NGT at baseline, 66 (21%) developed dysglycemia without reverting to NGT. Among children with dysglycemia at baseline, 24 (73%) reverted to NGT. In children with dysglycemia at 1st follow-up, 18 (53%) later reverted to NGT. Among biological, sociodemographic and lifestyle determinants at 8-10 years, only fasting and 2-h glucose were associated with developing dysglycemia (odds ratio [95% CI] per 1 mmol/L increase: 4.50 [1.06; 19.02] and 1.74 [1.11; 2.73], respectively). Beta-cell function decreased by 40% in children with overweight or obesity. In conclusion, up to 75% of children with dysglycemia reverted to NGT during puberty. Children with higher fasting and 2-h glucose were at higher risk for progression to dysglycemia, while no demographic/lifestyle determinants were identified.

Validation of desk-based audits using Google Street View® to monitor the obesogenic potential of neighbourhoods in a pediatric sample: a pilot study in the QUALITY cohort.

BACKGROUND: The suitability of geospatial services for auditing neighbourhood features relevant to pediatric obesity remains largely unexplored. Our objectives were to (i) establish the measurement properties of a desk-based audit instrument that uses Google Street View ® to assess street- and neighbourhood-level features relevant to pediatric obesity (QUALITY-NHOOD tool, the test method) and (ii) comment on its capacity to detect changes in the built environment over an 8-year period. In order to do so, we compared this tool with an on-site auditing instrument (the reference method). METHODS: On-site audits of 55 street- and neighbourhood-level features were completed in 2008 in 512 neighbourhoods from the QUALITY cohort study. In 2015, both repeat on-site and desk-based audits were completed in a random sample of 30 of these neighbourhoods. RESULTS: Agreement between both methods was excellent for almost all street segment items (range 91.9-99.7%), except for road type (81.0%), ads/commercial billboards (81.7%), road-sidewalk buffer zone (76.1%), and road-bicycle path buffer zone (53.3%). It was fair to poor for perceived quality, safety and aesthetics items (range 59.9-87.6%), as well as for general impression items (range 40.0-86.7%). The desk-based method over-detected commercial billboards and road-sidewalk buffer zone, and generally rated neighbourhoods as less safe, requiring more effort to get around, and having less aesthetic appeal. Change detected over the 8-year period was generally similar for both methods, except that the desk-based method appeared to amplify the increase in the number of segments with signs of social disorder. CONCLUSIONS: The QUALITY-NHOOD tool is deemed adequate for evaluating and monitoring changes in pedestrian- and traffic-related features applicable to pediatric populations. Applications for monitoring the obesogenic nature of neighbourhoods appear warranted.

Body Mass Index Z Score vs Weight-for-Length Z Score in Infancy and Cardiometabolic Outcomes at Age 8-10 Years.

OBJECTIVES: To confirm that World Health Organization weight-for-length z scores (zWFL) and World Health Organization body mass index z scores (zBMI) in infancy are associated with adiposity and cardiometabolic measures at 8-10 years old and to compare the predictive ability of the 2 methods. STUDY DESIGN: zWFL and zBMI at 6, 12, and 18 months of age were computed using data extracted from health booklets, among participants in the Québec Adipose and Lifestyle InvesTigation in Youth prospective cohort (n = 464). Outcome measures at 8-10 years included adiposity, lipid profile, blood pressure, and insulin dynamics. The relationships between zWFL, zBMI, and each outcome were estimated using multivariable linear regression models. Outcome prediction at 8-10 years was compared between the 2 methods using eta-squared and the Lin concordance correlation coefficient. RESULTS: zWFL and zBMI were associated with all measures of adiposity at 8-10 years. Associations with other cardiometabolic measures were less consistent. For both zWFL and zBMI across infancy, eta-squared were highly similar and the Lin coefficients were markedly high (≥0.991) for all outcomes. CONCLUSIONS: There was no evidence that zBMI and zWFL in infancy differed in their ability to predict adiposity and cardiometabolic measures in childhood. This lends support to the sole use of zBMI for growth monitoring and screening of overweight and obesity from birth to 18 years. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03356262.

Self-reported weight loss attempts and weight-related stress in childhood: Heightening the risk of obesity in early adolescence.

OBJECTIVE: Weight loss attempts occur as early as childhood. The impacts of weight loss attempts and weight-related stress on the occurrence of obesity during childhood remain unknown. We aimed to: (a) assess the prevalence of self-reported weight loss attempts and weight-related stress in 8-10 year-old children and (b) determine associations with adiposity 2 years later. METHOD: Data were collected from a cohort study of 564 Canadian children aged 8-10 years, having one or both biological parents with obesity (Quebec Adipose and Lifestyle Investigation in Youth cohort). Self-reported weight loss attempts and weight-related stress were assessed at baseline in the child's questionnaire. Adiposity was measured at baseline and 2 years later using body mass index z-scores (zBMI), waist-to-height ratio (WHtR), and percentage of body fat (%BF) obtained from dual-energy x-ray absorptiometry. Linear and logistic regression analyses were used while adjusting for potential confounders. RESULTS: Forty-eight percent of children reported previous weight loss attempts and 20% reported weight-related stress. Self-reported weight loss attempts and weight-related stress were associated with higher zBMI, WHtR, and %BF 2 years later in adjusted models, although estimates were attenuated when including baseline adiposity measures. Self-reported weight loss attempts, but not weight-related stress, increased the risk of becoming overweight among children who were normal weight at baseline. DISCUSSION: Weight loss attempts are prevalent in children with parental obesity. Children reporting weight loss attempts and weight-related stress tend to have higher adiposity 2 years later and are more likely to become overweight.

Breastfeeding duration in infancy and dietary intake in childhood and adolescence.

Although several studies have focused on associations between breastfeeding and child obesity, few have focused on associations with dietary intake. We examined associations between breastfeeding duration in infancy and dietary intake in childhood and explored whether associations are still observed in adolescence. The QUALITY (QUebec Adipose and Lifestyle InvesTigation in Youth) cohort includes 630 children aged 8-10 years at baseline (T1) who have at least one parent with obesity. A follow-up assessment was done 7 years later (T2) when participants were aged 15-17 years (n=377). Non-exclusive breastfeeding duration was evaluated at T1 using a parent questionnaire (never, < 3 months, 3-6 months, > 6 months). Dietary intake was assessed at T1 and T2 using three 24-h diet recalls, namely daily servings of vegetables (≥ 2 vs < 2), fruits (≥ 2 vs < 2), vegetables and fruits combined (≥ 5 vs < 5), sugar-sweetened beverages (SSB) (none vs any), and an overall diet quality index (DQI-I) (good vs poor). Multiple logistic regressions, adjusted for age, sex and total kilocalorie intake of the child, for age and body mass index of the mother, and for parental education and income were used. Compared to children breastfed > 6 months (reference group), those never breastfed or breastfed for 3-6 months were 42% (OR = 0.58, 95% CI: 0.34-0.96) and 38% (OR = 0.62, 95% CI: 0.39-1.00) less likely to consume ≥ 2 servings of vegetables per day at 8-10 years, respectively, while no association was found for those breastfed < 3 months. Compared to children breastfed > 6 months, those never breastfed were 1.8 times more likely to drink any SSB (OR = 1.82, 95% CI: 1.03-3.22). No associations were found for other diet indicators, and associations observed in childhood were no longer found by adolescence. In this cohort, breastfeeding was associated with greater vegetable intake and the avoidance of SSB in childhood, but not in adolescence, nor were associations found for fruit intake or overall diet quality.

Promoting healthy lifestyle behaviours in youth: Findings from a novel intervention for children at risk of cardiovascular disease.

OBJECTIVES: Obesity is the most prevalent risk factor for cardiovascular disease (CVD) in children. We developed a 2-year lifestyle intervention for youth at risk of CVD. We assessed changes in body mass index z-scores (zBMI) and key cardiometabolic risk factors, physical fitness, and capacity among those who completed the program. METHODS: The CIRCUIT program is a multidisciplinary lifestyle intervention for children aged 4 to 18 years at risk of CVD, based on a personalized plan to improve cardiometabolic outcomes by increasing physical activity and reducing sedentary behaviours. Both at baseline and 2-year follow-up, we measured zBMI, blood pressure z-scores (zBP), adiposity (%body and %trunk fat), fasting blood glucose and lipid profile, aerobic (VO2max) and anaerobic (5×5 m shuttle run test) fitness, and physical capacity indicators. Differences between baseline and follow-up were examined using paired t-tests (for age-sex standardized outcomes) and multivariable mixed effect models, adjusted for age and sex (for other outcomes). RESULTS: Among the 106 participants (53 males) who completed the 2-year program, mean age at baseline was 10.9 years (SD=3.2). After 2 years, zBMI and diastolic zBP decreased by 0.30SD (95% CI: -0.44; -0.16) and 0.43SD (95% CI: -0.65; -0.23), respectively. Participants improved %body and %trunk fat, lipid profile, aerobic and anaerobic fitness levels, and physical capacity (p<0.02). No changes in systolic zBP nor in fasting plasma glucose were observed. CONCLUSION: Our findings showed improved zBMI, cardiometabolic outcomes, physical fitness, and capacity among children at risk of CVD, suggesting that CIRCUIT is a promising intervention.

Determinants of new onset cardiometabolic risk among normal weight children.

OBJECTIVE: To identify determinants for the development of "normal weight metabolically unhealthy" (NWMU) profiles among previously metabolically healthy normal weight children. METHODS: The QUALITY cohort comprises youth 8-10 years of age with a parental history of obesity (n = 630). Of these, normal weight children with no metabolic risk factors were identified and followed up 2 years later (n = 193). Children were classified as NWMU if they remained normal weight but developed at least one cardiometabolic risk factor. They were classified as normal weight metabolically healthy otherwise. Multivariable logistic regression models were used to identify whether adiposity (anthropometrics and DXA), lifestyle habits (physical activity, screen time, vegetables, and fruit- and sugar-sweetened beverages intake), fitness, and family history of cardiometabolic disease were associated with new onset NWMU. RESULTS: Of the 193 normal weight and metabolically healthy children at baseline, 45 (23%) became NWMU 2 years later (i.e., 48% had elevated HDL cholesterol, 13% had elevated triglycerides, and 4% had impaired fasting glucose). Changes in adiposity between baseline and follow-up were associated with an increased risk of NWMU for all adiposity measures examined (e.g., for ∆zBMI OR = 3.95; 95% CI: 1.76, 8.83). Similarly, a 2-year change in screen time was associated with incident NWMU status (OR = 1.24; 95% CI 1.04, 1.49). CONCLUSIONS: Children who increase their adiposity levels as they enter puberty, despite remaining normal weight, are at risk of developing cardiometabolic risk factors. Studies examining long-term consequences of NWMU profiles in pediatrics are needed to determine whether changes in screening practice are warranted.

Public health nurse referrals for paediatric weight management: A nested mixed-methods study.

AIMS AND OBJECTIVES: To (a) characterise and determine proportions of referred and enrolled children and (b) explore public health nurses' (PHNs) experiences, perspectives and recommendations regarding a new nurse-led referral pathway for paediatric weight management. BACKGROUND: Children with obesity and their families in Canada access specialised services for obesity management through physician referral. Since this requirement can prevent timely access to health services, we established and tested a referral pathway whereby PHNs directly refer children to specialised care for obesity management. DESIGN: Nested mixed-methods study reported using GRAMMS. METHOD: Our research study included children (2-17 years of age; body mass index ≥85th percentile) referred by a PHN to the Pediatric Centre for Weight and Health (PCWH; Stollery Children's Hospital, Edmonton, Alberta, Canada) from April 2017-September 2018. We summarised referral and enrolment data using descriptive statistics and conducted one-on-one, semi-structured telephone interviews with PHNs; interviews were audio-recorded, transcribed verbatim, managed using NVivo 12 and analysed by two independent reviewers using content analysis. RESULTS: Our sample included 79 referred children (4.4 ± 1.8 years old; 3.4 ± 1.3 BMI z-score; 52.7% male), of which 47 (59.5%) enrolled in care. PHNs' (n = 11) experiences, perspectives and recommendations regarding the new referral pathway were grouped into four categories: (a) practicality of the referral pathway (e.g., simple and straightforward), (b) utility of the referral pathway (e.g., economic and timesaving), (c) uptake of the referral pathway (e.g., physician's influence) and (d) recommendations to improve the referral pathway (e.g., having electronic access to the referral form). CONCLUSIONS: A PHN-specific referral pathway led most children and families to enrol in paediatric weight management and overall was perceived as acceptable and appropriate among PHNs. RELEVANCE TO CLINICAL PRACTICE: Our results highlight the valuable role that PHNs can play in directly referring children to specialised services for weight management. This pathway has the potential to reduce wait times and enhance treatment enrolment.

Lifestyle Habits, Dietary Factors, and the Metabolically Unhealthy Obese Phenotype in Youth.

OBJECTIVE: To determine whether lifestyle habits and dietary factors at age 8-10 years predict the development of metabolically unhealthy obesity 2 years later among children who were previously metabolically healthy obese. STUDY DESIGN: The QUebec Adipose and Lifestyle InvesTigation in Youth cohort comprises 630 youth with a parental history of obesity. Metabolically healthy obesity and metabolically unhealthy obesity were defined using cut-offs for the components of pediatric metabolic syndrome. Dietary factors, physical activity, fitness, sedentary behavior, screen time, and sleep duration were measured. Multivariable logistic regressions were used to examine associations. RESULTS: At baseline, 48 participants with metabolically healthy obesity were identified; 2 years later, 19 became metabolically unhealthy obese and 29 remained metabolically healthy obese. Every additional daily portion of fruits and vegetables decreased the risk of converting to metabolically unhealthy obesity by 39% (OR 0.61, 95% CI 0.40-0.94). Cumulating more hours of screen time and diets high in saturated fat and sugar-sweetened beverages and low in protein were associated with a tendency to develop metabolically unhealthy obesity. CONCLUSIONS: Fruit and vegetable intake and possibly screen time, saturated fat, sugar-sweetened beverages, and protein intake may be important targets for the prevention of cardiometabolic complications in obese children. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03356262.

Normal weight metabolically unhealthy phenotype in youth: Do definitions matter?

BACKGROUND: Normal weight metabolically unhealthy (NWMU) adults are at increased risk of cardiometabolic disease, however, little is known regarding NWMU children. OBJECTIVES: We examined the associations between existing definitions of NWMU in children aged 8 to 10 years and insulin sensitivity (IS) and secretion 2 years later. METHODS: Data stem from the Quebec Adipose and Lifestyle InvesTigation in Youth (QUALITY) cohort of 630 Caucasian youth, 8 to 10 years old at baseline, with at least one obese biological parent. Of these, 322 normal weight children were classified as NWMU using four definitions. At 10 to 12 years, IS was measured with the Matsuda-insulin sensitivity index; insulin secretion was measured with the ratio of the area under the curve (AUC) of insulin to the AUC of glucose over a 2-hour oral glucose tolerance test. Multiple linear regression models were used. RESULTS: Because few children met the existing definitions of metabolic syndrome, associations were examined for less stringent definitions (eg, having two vs no risk factors). At baseline, IS was lower in NWMU children compared to children with no risk factors (virtually all definitions). Moreover, after 2 years, IS was 14.4-19.3% lower in NWMU children with one or more risk factors, and up to 29.7% lower in those with two or more risk factors compared to those with none. Insulin secretion was not predicted by components of the metabolic syndrome. CONCLUSION: Existing definitions of NWMU youth performed relatively similarly in predicting IS as youth entered puberty. Children with one or more components of metabolic syndrome-even when of normal weight-have significantly lower IS over time.

Lowering Saturated Fat and Increasing Vegetable and Fruit Intake May Increase Insulin Sensitivity 2 Years Later in Children with a Family History of Obesity.

Background: Identifying dietary factors that determine insulin sensitivity and secretion in children entering puberty may provide valuable information for the early prevention of type 2 diabetes. Objectives: We assessed whether macronutrients and food groups are longitudinally associated with insulin sensitivity and secretion over a 2-y period in children with a family history of obesity, and whether associations differ by level of adiposity. Methods: Data were derived from the Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) Study, an ongoing prospective cohort including 630 children recruited at ages 8-10 y, with ≥1 obese parent, and followed 2 y later (n = 564). The intake of macronutrients and foods was assessed at baseline using three 24-h dietary recalls. At age 10-12 y, insulin sensitivity was assessed by the Matsuda Insulin Sensitivity Index (ISI) and the homeostatic model assessment of insulin resistance. Insulin secretion was assessed by the ratio of the area under the curve of insulin to the area under the curve of glucose at 30 min and at 120 min of an oral-glucose-tolerance test. Multivariable linear regression models were fitted for each dietary factor while adjusting for age, sex, puberty, physical activity, screen time, total energy intake, and percentage of body fat; and interaction terms between dietary factors and percentage of body fat were tested. Results: Saturated fat intake was associated with a 1.95% lower (95% CI: -3.74%, -0.16%) Matsuda ISI, whereas vegetable and fruit intake was associated with a 2.35% higher (95% CI: 0.18%, 4.52%) Matsuda ISI 2 y later. The association of saturated fat intake with insulin sensitivity was most deleterious among children with a higher percentage of body fat (P-interaction = 0.023). Other than fiber intake, no longitudinal associations between dietary intake and insulin secretion were found. Conclusions: Lowering saturated fat and increasing vegetable and fruit intakes during childhood may improve insulin sensitivity as children enter puberty. This study was registered at www.clinicaltrials.gov as NCT03356262.

Identifying risk profiles for childhood obesity using recursive partitioning based on individual, familial, and neighborhood environment factors.

BACKGROUND: Few studies consider how risk factors within multiple levels of influence operate synergistically to determine childhood obesity. We used recursive partitioning analysis to identify unique combinations of individual, familial, and neighborhood factors that best predict obesity in children, and tested whether these predict 2-year changes in body mass index (BMI). METHODS: Data were collected in 2005-2008 and in 2008-2011 for 512 Quebec youth (8-10 years at baseline) with a history of parental obesity (QUALITY study). CDC age- and sex-specific BMI percentiles were computed and children were considered obese if their BMI was ≥95th percentile. Individual (physical activity and sugar-sweetened beverage intake), familial (household socioeconomic status and measures of parental obesity including both BMI and waist circumference), and neighborhood (disadvantage, prestige, and presence of parks, convenience stores, and fast food restaurants) factors were examined. Recursive partitioning, a method that generates a classification tree predicting obesity based on combined exposure to a series of variables, was used. Associations between resulting varying risk group membership and BMI percentile at baseline and 2-year follow up were examined using linear regression. RESULTS: Recursive partitioning yielded 7 subgroups with a prevalence of obesity equal to 8%, 11%, 26%, 28%, 41%, 60%, and 63%, respectively. The 2 highest risk subgroups comprised i) children not meeting physical activity guidelines, with at least one BMI-defined obese parent and 2 abdominally obese parents, living in disadvantaged neighborhoods without parks and, ii) children with these characteristics, except with access to ≥1 park and with access to ≥1 convenience store. Group membership was strongly associated with BMI at baseline, but did not systematically predict change in BMI. CONCLUSION: Findings support the notion that obesity is predicted by multiple factors in different settings and provide some indications of potentially obesogenic environments. Alternate group definitions as well as longer duration of follow up should be investigated to predict change in obesity.

A reliability assessment of a direct-observation park evaluation tool: the parks, activity and recreation among kids (PARK) tool.

BACKGROUND: Parks are increasingly being viewed as a resource that may influence youth obesity and physical activity (PA). Assessing park quality can be challenging as few tools assess park characteristics geared towards youth PA. Additionally, no studies have compared reliability estimates of items assessed in different countries, hindering aims towards generalizable park audit items. Finally, new satellite imaging technology is allowing for desktop identification of parks, however it remains unclear how this compares to direct observation park identification. The purpose of this study is 1) to describe the development and reliability of a youth-oriented direct-observation park audit tool tested in Montreal, Canada, and; 2) to compare reliability estimates of items with those drawn from a tool previously tested in Perth, Australia, with those same items tested in Montreal, Canada. METHODS: Items were drawn and adapted from two existing tools and 13 new items were newly developed for a total of 92 items. Parks were pre-identified using a GIS software and then verified and audited on-site by observers. A total of 576 parks were evaluated. Cohen's kappa and percent agreement were used to assess the inter- and intra-rater reliability of each item. Inter-rater reliabilities of 17 items drawn from a tool previously tested in Australia were compared. RESULTS: Eighty-six percent of items had ≥ 75 % agreement and 83 % had kappa coefficients between 0.41 and 1. Among 40 test-retest episodes kappa agreement was relatively high (≥ 0.40) for all but four items. Percent agreement was excellent (≥ 75 % agreement) for all but eight items. Inter-rater reliability estimates of the 17 items tested in Montreal and Perth were of similar magnitude. CONCLUSIONS: The tool is generally reliable and can be used to assess park characteristics that may be associated with youth PA. The items tested in Montreal and Perth are likely generalizable to other urban environments.