Adiposity and cardiac autonomic function in children with a family history of obesity.

PURPOSE: Data on associations between adiposity and heart rate variability (HRV) in prepubertal children are limited. We examined the associations between adiposity indices and HRV, independent of lifestyle behaviors, comparing multiple indicators of adiposity, and explored differences between boys and girls. METHODS: Data stem from 469 participants of the QUALITY cohort (630 children aged 8-10 years with a parental history of obesity). Adiposity indices included waist-to-height ratio, body mass index (BMI) percentiles and categories (overweight, obesity), dual-energy x-ray absorptiometry (DEXA) defined fat mass percentage and android/gynoid ratio. HRV indices in the frequency and the spectral domain were derived from a daytime 3-h Holter recording. Multivariable linear regression models were adjusted for age, sex, Tanner stage, physical activity, screen time, and fitness. Interactions between sex and adiposity were tested. RESULTS: Greater adiposity was associated with decreased parasympathetic modulation and increased sympathetic dominance. Waist-to-height ratio was associated with lower parasympathetic activity: root mean square of the successive differences (RMSSD) [B = -23.32, 95% confidence interval (CI) -42.42, -4.22], pNN50 (B = -16.93, 95% CI - 28.58, - 5.27), LF/HF ratio (B = 1.83, 95% CI 0.97-2.70). Patterns of association were similar for android/gynoid ratio. Overweight was not associated with altered HRV. Obesity was negatively associated with RMSSD and pNN50 and positively with LF/HF ratio. Greater fat mass percentage was associated with lower RMSSD, pNN50, and HF, and increased LF/HF ratio. There were no differences between boys and girls. CONCLUSIONS: Specific markers of adiposity relate to altered HRV in childhood, with waist-to-height ratio being potentially a more relevant marker of HRV than BMI and more pragmatic than percent body fat. TRIAL REGISTRATION: NCT03356262, 11 November 2017.

The association between depressive symptoms and overweight or obesity in prepubertal children: Findings from the QUALITY cohort.

BACKGROUND: Youth obesity and depression are public health concerns. Although meta-analyses suggest a positive association between those conditions in adults and adolescents, evidence remains unclear in prepubertal children. We examined the bidirectional associations between levels of depressive symptoms and weight status in 8-10-year-old children with a parental history of obesity, over two years, and whether they differ by sex. METHODS: Data were drawn from the QUebec Adipose and Lifestyle InvesTigation in Youth Cohort Study's baseline and first follow-up evaluations (n = 558). Depressive symptoms were assessed using the 12-item Center for Epidemiological Studies Depression scale and weight status using body mass index z-scores based on World Health Organization standards. Linear and logistic regression models were used to test the directionality and magnitude of the associations, adjusting for age, sex, physical activity, screen time, parental education, alcohol and cigarette use, and baseline outcome measure. RESULTS: Children with higher levels of depressive symptoms at baseline were not more likely to have overweight/obesity at follow-up (odds ratio [95 % Coefficient Interval] = 0.95[0.88;1.02]). Baseline overweight/obesity was not associated with subsequent higher levels of depressive symptoms (beta coefficient [95 % Coefficient Interval] = 0.20 [-0.47;0.87]). No sex differences emerged. LIMITATIONS: Selection bias may have occurred due to loss at follow-up (10 % attrition) and exclusion of 6 participants taking mood disorder medication. CONCLUSIONS: Unlike in adults and adolescents, no association between weight status and depressive symptoms was observed in childhood over two years. Underlying mechanisms linking both conditions later in life may not apply as early as prepubertal childhood.

Neighbourhood Environments and Lifestyle Behaviours in Adolescents With Type 1 Diabetes.

OBJECTIVES: Early prevention strategies are needed to mitigate the high risk of cardiovascular disease in adolescents with type 1 diabetes (T1D). Residential neighbourhood features can promote healthy lifestyle behaviours and reduce cardiovascular risk, but less is known about their role in lifestyle behaviours in adolescents with T1D, and no studies used comparisons to healthy controls. METHODS: We examined associations between residential neighbourhood features and lifestyle behaviours in adolescents with T1D and healthy controls. Data were analyzed from the CARdiovascular Disease risk factors in pEdiatric type 1 diAbetes (CARDEA) study, a cross-sectional investigation of 100 adolescents with T1D (14 to 18 years) from a pediatric diabetes clinic in Montréal, Canada, and 97 healthy controls. Outcomes included physical activity and sedentary behaviour (accelerometry), screen time and sleep duration (questionnaires), and dietary habits (24-hour recalls). Cluster analysis of selected neighbourhood indicators computed for participants' postal codes resulted in 2 neighbourhood types: central urban and peri-urban. Central urban neighbourhoods were characterized by very high population density, high active living index, numerous points of interest, higher social deprivation, higher residential mobility, and lower median household income compared with peri-urban neighbourhoods. Associations of neighbourhood type with lifestyle behaviours were estimated with multiple linear regressions and interactions by T1D status were tested. RESULTS: Living in central urban neighbourhoods was associated with greater daily minutes of moderate-to-vigourous physical activity (beta = 8.61, 95% confidence interval 1.79 to 15.44) compared with living in peri-urban neighbourhoods. No associations were observed for other lifestyle behaviours, and no statistically significant interactions were found between neighbourhood type and T1D status. CONCLUSION: Features that characterize central urban built environments appear to promote physical activity in adolescents, regardless of T1D status.

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 Meal Environment Differentially Conditions the Prospective Association between Early Childhood Screen Time and Key Social Relationships in Adolescent Girls.

Background: Despite screen time recommendations, children are increasingly spending time on electronic devices, rendering it an important risk factor for subsequent social and developmental outcomes. Sharing meals could offer a way to promote psychosocial development. This study examines the interaction between family meal environment and early childhood screen time on key adolescent social relationships. Methods: Participants are 1455 millennial children (49% boys) from the Quebec Longitudinal Study of Child Development birth cohort. Parents reported on child screen use at ages 2 and 6 years and family meal environment quality at age 6 years. Parents and children reported on parent-child relationships and peer victimization experiences, respectively, at age 13 years. Sex-stratified multiple regression estimated the direct association between screen time trends, family meal environment quality, and their interaction on later social relationship outcomes. Results: For girls, when preschool screen time increased, sharing family meals in high-quality environments was associated with more positive and less conflictual relationships with their mothers, whereas meals shared in low- and moderate-quality environments were associated with fewer instances of victimization by their peers. Non-linear associations were not significant for boys. Conclusion: Capitalizing on family meal environment represents a simple/cost-efficient activity that can compensate for some long-term risks associated with increased screen use, above and beyond pre-existing and concurrent individual and family characteristics. Public health initiatives may benefit from considering family meals as a complementary intervention strategy to screen use guidelines.

Children and chrono-exercise: Timing of physical activity on school and weekend days depends on sex and obesity status.

Recommendations for physical activity (PA) typically focus on frequency, intensity, duration, and type, but timing (chrono-exercise) is also important. The objective of this study is to describe when children are active on school and weekend days and explore PA timing across sex and body mass index (BMI) categories. 359 children (53% male), aged 9.6 (0.9) y, were categorized as normal weight (≥-1 standard deviations (SD) and <1SD; n = 193), overweight (≥1SD and <2SD; n = 80), or obese (≥2SD; n = 86) using WHO BMIz. Moderate-to-vigorous PA (MVPA) was assessed using ActiGraph LS-7164. The results are described as Mean(SD). ANOVA evaluated MVPA across sexes and BMI categories. Normal weight boys were more active than boys with obesity on school (Δ20.33 min; p < 0.001) and weekend days (Δ15.04 min; p < 0.05). On school days, significant differences existed between 9:00 h-11:00 h and 12:00 h-14:00 h (p < 0.017), while on weekends, smaller differences existed throughout the day. Girls' MVPA was similar across BMI categories, on all days (p > 0.05). On school days, 12:00 h-13:00 h represented the most active hour for all participants (~14% total daily MVPA). Peak weekend MVPA was distributed across multiple hours. Differences in MVPA timing emerged on school-days and weekends. Timing may be important when examining the nuances of MVPA in relation to sex and bodyweight in children.

Early Lifestyle Determinants of Adiposity Trajectories from Childhood into Late Adolescence.

Objective: The aim of this study was to examine associations of childhood physical activity, sedentary behavior, and dietary intake with adiposity trajectories from childhood to adolescence. Methods: Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) cohort (n = 630) data from 3 time points (8-10, 10-12, and 15-17 years) for 377 Caucasian children with parental obesity were analyzed. Height and weight, physical activity and sedentary behavior (7-day accelerometry), screen time (self-reported), and dietary intake (three 24-hour diet recalls) were measured. Group-based trajectory modeling identified longitudinal trajectories of body-mass index z-scores (zBMIs). Inverse probability of exposure-weighted multinomial logistic regressions examined associations between baseline lifestyles and zBMI trajectory groups. Results: Six trajectory groups were identified: Stable-Low-Normal-Weight (two groups, 5.7% and 33.0%, which were combined), Stable-High-Normal-Weight (24.8%), Stable-Overweight (19.8%), Stable-Obesity (8.8%), and Overweight-Decreasers (7.9%). For every additional portion of fruits and vegetables, the likelihood of being in the group of Overweight-Decreasers increased by 29% (odds ratio [OR]: 1.29, 95% confidence interval [CI]: 1.09-1.55) compared with the reference group (Stable-Low-Normal-Weight). For every additional hour of sedentary behavior, the likelihood of belonging to the group of Overweight-Decreasers increased 2-fold (OR: 1.99, 95% CI: 1.28-3.21) and Stable-Obesity increased 1.5-fold (OR: 1.56, 95% CI: 1.08-2.23), compared with the reference. Every additional 10 minutes of moderate-to-vigorous physical activity was associated with a lower likelihood of belonging to the Stable-Obesity group (OR: 0.75, 95% CI: 0.61-0.89) and to the group of Overweight-Decreasers (OR: 0.79, 95% CI: 0.64-0.95) compared with the reference. Finally, children were more likely to belong to the Stable-Obesity group with each additional hour/day of screen time (OR: 1.23, 95% CI: 1.01-1.58). Conclusions: Trajectories of zBMIs from childhood to late adolescence were stable, except for one group which decreased from overweight in childhood to normal weight in adolescence. The latter had more favorable baseline dietary intake of fruits and vegetables. ClinicalTrials.org no. NCT03356262.

Multidimensional school features associated with physical activity among youth at risk of obesity: an exploratory principal component and generalized estimating equation analysis.

BACKGROUND: Schools may be high-leverage points for the promotion of physical activity (PA), yet little is known about school built and social environments among youth at high risk of obesity. PURPOSE: To characterise school built and social environments that may be salient for PA and to examine associations between school PA environments and PA in youth at risk of obesity. METHODS: Data from youth attending 206 schools (314 youth in 2005-2008, and 129 youth in 2008-2010) within the QUALITY cohort study, a longitudinal investigation of youth at high risk of obesity were used. Features of schools, based on built, policy/programming and social environments were identified using principal components (PC) analysis. Gender-stratified generalized estimating equation (GEE) models were used to explore associations between school features and accelerometer measured mean counts per minute (MCPM), mean daily moderate-to-vigorous physical activity (MVPA) and the odds of meeting MVPA guidelines cross-sectionally and prospectively using 90% confidence intervals. RESULTS: Nine PCs were identified. Associations were observed between PA and 7 of the 9 PCs. The social environment seemed to be particularly important. Social Norms to Promote PA was associated with an increase in girls' baseline MCPM and MVPA. High Willingness to Promote PA was associated with boys' MCPM, MVPA, and odds of meeting MVPA guidelines, at both baseline and follow-up. CONCLUSION: School built and social contexts may be associated with PA cross-sectionally and over time. Further studies are necessary to confirm the direction and magnitude of effects and to establish their relevance to school-based health promotion efforts.

The association between income inequality and adolescent body mass index: findings from the COMPASS study (2016-2019).

OBJECTIVES: Income inequality has been linked to high and unhealthy body mass index (BMI), though there is a dearth of evidence in adolescents. Therefore, this study examines the association between income inequality and BMI in a large sample of Canadian adolescents. METHODS: A pooled cross-sectional design was used. Participants were adolescents (n = 101,901) from 157 Canadian secondary schools participating in the 2016-2017, 2017-2018, or 2018-2019 waves of the Cannabis, Obesity, Mental health, Physical activity, Alcohol, Smoking, and Sedentary behaviour (COMPASS) study. BMI was calculated from self-reported height and weight and converted to World Health Organization (WHO) z-BMI scores. Gini coefficients were calculated at the census division level (n = 49) using data from the 2016 Canadian Census. Multilevel modelling was performed to account for the clustering of students nested within schools, which were nested within census divisions. Interactions were included to determine whether associations were heterogeneous for males and females. RESULTS: Income inequality demonstrated a non-linear association with WHO z-BMI score (z-Gini: ß = 0.05, 95%CI: 0.02, 0.08; z-Gini2: ß = -0.02, 95% CI: -0.04, -0.01) among adolescents after adjusting for student-, school-, and census division-level covariates. This association was more pronounced among females. CONCLUSION: The association between income inequality and BMI, being overweight, or having obesity appears to be non-linear. Public health units and schools may benefit from incorporating upstream factors such as income inequality into their interventions attempting to promote healthy weights.

RéSUMé: OBJECTIFS: L'inégalité des revenus a été liée à un indice de masse corporelle (IMC) élevé et malsain, bien qu'il y ait un manque de preuves chez les adolescents. Par conséquent, la présente étude examine l'association entre l'inégalité des revenus et l'IMC dans un vaste échantillon d'adolescents canadiens. MéTHODES: Un devis comprenant des études transversales groupées a été utilisé. Les participants étaient des adolescents (n = 101 901) de 157 écoles secondaires canadiennes participant aux vagues 2016-2017, 2017-2018 ou 2018-2019 de l'étude COMPASS (Cannabis, Obésité, Santé mentale, Activité physique, Alcool, Tabagisme et Comportement sédentaire). L'IMC a été calculé à partir de la taille et du poids auto-déclarés et convertis en scores z selon l'Organisation mondiale de la santé (OMS). Les coefficients de Gini ont été calculés à l'échelle du secteur de recensement (n = 49) en utilisant les données du Recensement canadien de 2016. Des modèles multiniveaux ont été effectués pour tenir compte du regroupement des élèves dans les écoles, qui elles-mêmes étaient incluses dans les secteurs de recensement. Des variables d'interactions ont été incluses dans les modèles afin de permettre une comparaison des paramètres estimés entre les hommes et les femmes. RéSULTATS: L'inégalité des revenus a démontré une association non linéaire avec le score de l'IMC z de l'OMS (z-Gini : ß = 0,05, IC à 95 % : 0,02, 0,08; z-Gini2 : ß = -0,02, IC à 95 % : -0,04, -0,01) chez les adolescents après ajustement pour tenir compte des covariables au niveau des élèves, de l'école et des divisions de recensement. Cette association était plus prononcée chez les femmes. CONCLUSION: L'association entre l'inégalité des revenus et l'IMC, l'embonpoint ou l'obésité semble être non linéaire. Les bureaux de santé publique et les écoles pourraient tirer profit de l'intégration de facteurs en amont comme l'inégalité des revenus dans leurs interventions visant à promouvoir le poids santé.

Neighbourhood social deprivation and risk of prostate cancer.

BACKGROUND: Striking geographic variations in prostate cancer incidence suggest an aetiological role for spatially-distributed factors. We assessed whether neighbourhood social deprivation, which can reflect limited social contacts, unfavourable lifestyle and environmental exposures, is associated with prostate cancer risk. METHODS: In 2005-2012, we recruited 1931 incident prostate cancer cases and 1994 controls in a case-control study in Montreal, Canada. Lifetime residential addresses were linked to an area-based social deprivation index around recruitment (2006) and about 10 years earlier (1996). Logistic regression estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Men residing in areas characterised by greater social deprivation had elevated prostate cancer risks (ORs of 1.54 and 1.60 for recent and past exposures, respectively; highest vs lowest quintiles), independently from area- and individual-level confounders and screening patterns. The increase in risk with recent high social deprivation was particularly elevated for high-grade prostate cancer at diagnosis (OR 1.87, 95% CI 1.32-2.64). Associations were more pronounced for neighbourhoods with higher proportions of separated/divorced or widowed individuals in the past, and with higher percentages of residents living alone recently. CONCLUSIONS: These novel findings, suggesting that neighbourhood-level social deprivation increases the risk of prostate cancer, point out to potential targeted public health interventions.

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.

Association between annual exposure to air pollution and systolic blood pressure among adolescents in Montréal, Canada. / Association entre l'exposition annuelle à la pollution atmosphérique et la pression artérielle systolique chez des adolescents à Montréal (Canada).

INTRODUCTION: In adults, chronic exposure to air pollution is associated with elevated blood pressure, but few studies have examined this relationship in youth. We investigated the association between annual ambient concentrations of air pollutants (fine particulate matter [PM2.5] and nitrogen dioxide [NO2]) and systolic blood pressure (SBP) among adolescents in Montréal, Canada. METHODS: Participants were students aged 15 to 17 years who provided SBP and residential postal code data in 2004/05 through their enrolment in the Nicotine Dependence in Teens study. Annual estimates for 2004 of residential exposure to NO2 and PM2.5 were provided by the Canadian Urban Environmental Health Research Consortium and linked to participants' residential postal code. Elevated SBP was defined as SBP ≥ 90th percentile adjusted for age, sex and height. Logistic regression was used to estimate odds ratios and 95% confidence intervals (CIs) for each pollutant with respect to elevated SBP, adjusted for relevant confounders. RESULTS: The sample consisted of 508 adolescents (mean age: 16.9, 46% male); 4% had elevated SBP. Although estimates were not statistically significant, there were generally modest positive associations between pollutant levels and SBP. The adjusted prevalence odds ratio of elevated SBP was 1.33 (95% CI: 0.64, 3.05) for every interquartile range (IQR) increase in residential PM2.5 levels (2.1µg/m3). Similarly, the adjusted prevalence odds ratio of elevated SBP was 1.17 (95% CI: 0.47, 2.70) for every IQR increase in residential NO2 levels (10.2 ppb). CONCLUSION: Findings support a possible relationship between exposure to air pollutants and increased SBP in adolescents, warranting further investigation for this important public health concern.

Impact of Unmet Social Needs, Scarcity, and Future Discounting on Adherence to Treatment in Children With Asthma: Protocol for a Prospective Cohort Study.

BACKGROUND: Asthma is one of the most prevalent chronic diseases of childhood and disproportionately affects children with lower socioeconomic status. Controller medications such as inhaled corticosteroids significantly reduce asthma exacerbations and improve symptoms. However, a large proportion of children still have poor asthma control, in part owing to suboptimal adherence. Financial barriers contribute to hindering adherence, as do behavioral factors related to low income. For example, unmet social needs for food, lodging, and childcare may create stress and worry in parents, negatively influencing medication adherence. These needs are also cognitively taxing and force families to focus on immediate needs, leading to scarcity and heightening future discounting; thus, there is the tendency to attribute greater value to the present than to the future in making decisions. OBJECTIVE: In this project, we will investigate the relationship between unmet social needs, scarcity, and future discounting as well as their predictive power over time on medication adherence in children with asthma. METHODS: This 12-month prospective observational cohort study will recruit 200 families of children aged 2 to 17 years at the Asthma Clinic of the Centre Hospitalier Universitaire Sainte-Justine, a tertiary care pediatric hospital in Montreal, Canada. The primary outcome will be adherence to controller medication, measured using the proportion of prescribed days covered during follow-up. Exploratory outcomes will include health care use. The main independent variables will be unmet social needs, scarcity, and future discounting, measured using validated instruments. These variables will be measured at recruitment as well as at 6- and 12-month follow-ups. Covariates will include sociodemographics, disease and treatment characteristics, and parental stress. Primary analysis will compare adherence to controller medication, measured using the proportion of prescribed days covered, between families with versus those without unmet social needs during the study period using multivariate linear regression. RESULTS: The research activities of this study began in December 2021. Participant enrollment and data collection began in August 2022 and are expected to continue until September 2024. CONCLUSIONS: This project will allow the documentation of the impact of unmet social needs, scarcity, and future discounting on adherence in children with asthma using robust metrics of adherence and validated measures of scarcity and future discounting. If the relationship between unmet social needs, behavioral factors, and adherence is supported by our findings, this will suggest the potential for novel targets for integrated social care interventions to improve adherence to controller medication and reduce risk across the life course for vulnerable children with asthma. TRIAL REGISTRATION: ClinicalTrials.gov NCT05278000; https://clinicaltrials.gov/ct2/show/NCT05278000. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/37318.

Invited Commentary: Cross-Sectional Studies and Causal Inference-It's Complicated.

In this issue of the Journal, Savitz and Wellenius (Am J Epidemiol. 2023;192(4):514-516) discuss the contribution of cross-sectional studies to causal inference when the data are used to address etiological research questions. We elaborate on their thoughts with a discussion of the conditions needed for addressing etiology with the cross-sectional design, using a modern causal inference lens.

Adolescents' reports of chaos within the family home environment: Investigating associations with lifestyle behaviours and obesity.

OBJECTIVE: Disorganised and chaotic home environments may hinder the adoption of healthy lifestyle behaviours and contribute to excessive weight gain among adolescents. We examined whether self-reported level of chaos within the family home environment is associated with lifestyle behaviours and obesity in adolescent girls and boys. METHODS: Cross-sectional data from the 3rd wave of the Québec Adipose and Lifestyle Investigation in Youth (QUALITY) study were analyzed. The sample consisted of n = 377 White adolescents with a history of parental obesity. Home environment chaos was measured using the Confusion, Hubbub, and Order Scale (CHAOS) analyzed both continuously and dichotomized as high vs. low chaos. Body Mass Index z-scores (zBMI) were computed using WHO standards from measured weight and height. Physical activity (7-day accelerometry), vegetable and fruit intake (three 24-hour diet recalls), and leisure screen time and sleep duration (questionnaire) were assessed. Sex-specific linear regression models were used to estimate associations between level of family home environment chaos, lifestyle behaviours and zBMI. RESULTS: The overall level of chaos was low in our study sample, with higher reported levels among girls compared to boys. Among girls, high (vs low) chaos was associated with shorter sleep duration (hours/day) (B = - 0.44, 95% CI: -0.75, -0.14). No associations were observed for other lifestyle behaviours or for zBMI. CONCLUSION: In this sample of adolescents with a parental history of obesity, higher household chaos was not associated with obesity or lifestyle behaviours, except for sleep duration among girls. Replication of findings in more diverse samples is indicated.

Estimating causal effects of physical activity and sedentary behaviours on the development of type 2 diabetes in at-risk children from childhood to late adolescence: an analysis of the QUALITY cohort.

BACKGROUND: Uncertainty remains regarding the causal effect of physical activity and sedentary behaviours on the development of type 2 diabetes in children. We aimed to estimate average treatment effects of physical activity and sedentary behaviours on risk of type 2 diabetes in individuals who are at risk during childhood and adolescence. METHODS: We used data from the Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) cohort of children of western European descent (white non-Hispanic race or ethnicity) with a parental history of obesity (defined as a BMI of 30 kg/m2 or more, or a waist circumference of more than 102 cm in men and 88 cm in women) evaluated at the ages of 8-10 years (baseline), 10-12 years (first follow-up cycle), and 15-17 years (second follow-up cycle) in Québec, Canada. We measured moderate-to-vigorous physical activity (MVPA) and sedentary time by accelerometry, and leisure screen time by questionnaire at each cycle. Outcomes included fasting and 2 h post-load glycaemia and validated indices of insulin sensitivity and insulin secretion. We estimated average treatment effects of MVPA, sedentary time, and screen time on markers of type 2 diabetes using longitudinal marginal structural models with time-varying exposures, outcomes, and confounders from the ages of 8-10 to 15-17 years and inverse probability of treatment and censoring weighting. We considered both the current and cumulative effects of exposures on outcomes. FINDINGS: 630 children were evaluated at baseline (age 8-10 years) between July, 2005, and December, 2008, 564 were evaluated at the first follow-up (age 10-12 years) between July, 2007, and March, 2011, and 377 were evaluated at the second follow-up (age 15-17 years) between September, 2012, and May, 2016. Based on cumulative exposure results, estimated average treatment effects for MVPA were 5·6% (95% CI 2·8 to 8·5) on insulin sensitivity and -3·8% (-7·1 to -0·5) on second-phase insulin secretion per 10 min daily increment from the ages of 8-10 years to age 15-17 years. Average treatment effects for sedentary time and reported screen time resulted in reduced insulin sensitivity (-8·2% [-12·3 to -3·9] and -6·4% [-10·1 to -2·5], respectively), increased second-phase insulin secretion (5·9% [1·9 to 10·1] and 7·0% [-0·1 to 14·7], respectively), and higher fasting glycaemia (0·03 mmol/L [0·003 to 0·05] and 0·02 mmol/L [0·01 to 0·03], respectively) per additional daily hour from the ages of 8-10 years to 15-17 years. INTERPRETATION: Using modern causal inference approaches strengthened the evidence of MVPA and sedentary behaviours as key drivers of development of type 2 diabetes in at-risk children and adolescents, and should be considered as key targets for prevention. FUNDING: Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, and Fonds de Recherche du Québec-Santé. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Associations of neighborhood walkability with moderate to vigorous physical activity: an application of compositional data analysis comparing compositional and non-compositional approaches.

BACKGROUND: We compared the relation between neighborhood features and moderate to vigorous physical activity (MVPA) using linear regression analysis and the more novel compositional data analysis (CoDA). Compositional data analysis allows us to take the time children allocate to different movement behaviours during a 24-hour time period into account. METHODOLOGY: Data from youth participants (n = 409) in the QUALITY (QUebec Adipose and Lifestyle InvesTigation in Youth) cohort were included. Time spent in MVPA, light physical activity, sedentary behavior, and sleep ("24-hour movement behaviours") was measured using accelerometers. Neighborhood data were collected using a geographic information system and through direct observation. In CoDA models, we used orthogonal logratio coordinates, which allows for the association of neighbourhood walkability with MVPA to be estimated with respect to the average composition of all other behaviours within a 24-hour time frame. In baseline linear regression models, MVPA was regressed cross-sectionally on neighborhood walkability. All models were stratified by sex, and controlled for BMI z-scores, pubertal development, seasonal variation, parental education, and neighbourhood safety. RESULTS: Based on CoDA, girls who lived in more walkable neighborhoods had 10% higher daily MVPA (95% CI: 2%, 19%), taking into account all other movement behaviours. Based on linear regression, girls who resided in more walkable neighborhoods engaged in 4.2 (95% confidence interval [CI]: 1.2, 6.6) more minutes of MVPA per day on average than girls residing in less walkable neighborhoods. CONCLUSIONS: Unlike with traditional linear models, all movement behaviours were included in a single model using CoDA, allowing for a more complete picture of the strength and direction of the association between neighbourhood Walkability and MVPA. Application of CoDA to investigate determinants of physical activity provides additional insight into potential mechanisms and the ways in which people allocate their time.

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.