Associations Between Weight-Loss Attempts, Weight-Related Stress, and Body Image During Childhood and Adolescence in Children With Parental Obesity.

Background: Few longitudinal studies have investigated the role of weight-loss attempts or weight-related stress on body image during childhood. We examined whether weight-loss attempts and weight-related stress are associated with weight misperception and body dissatisfaction across childhood and adolescence. Methods: Data were drawn from the Quebec Adipose and Lifestyle InvesTigation in Youth (QUALITY) cohort of Canadian children with parental obesity (8-10 years: n = 630; 10-12 years: n = 564; 15-17 years: n = 377). We assessed weight-loss attempts and weight-related stress at baseline and first follow-up, and perceived and desired silhouettes at first and second follow-up with questionnaires. Weight misperception consisted of the difference in BMI z-score (zBMI) from the perceived silhouette and the measured zBMI. Body dissatisfaction consisted of the discordance between perceived and desired silhouettes. We estimated multivariable mixed-effects regression models adjusting for age, sex, pubertal stage, parental BMI and education, and sport-based teasing. Results: Weight loss attempts were associated with a higher weight misperception score (ever tried, beta [95% confidence intervals; CI]: 0.13 [0.01-0.24]) and with 2.13 times higher desire to be thinner (95% CI: 1.39-3.26) at the subsequent follow-up. Similarly, children stressed by their weight had a higher misperception score (beta [95% CI]: 0.15 [0.02-0.27]) and greater desire to be thinner at the next follow-up (odds ratio [95% CI]: 1.73 [0.999-3.00]). Conclusions: Weight-loss attempts and weight-related stress in children and adolescents are associated with weight misperception and body dissatisfaction, supporting empowerment and counseling focusing on healthy eating behaviors and a positive body image. Clinical Trial Registration Number: NCT03356262.

DEXA-based Fat Mass with the Risk of Worsening Insulin Resistance in Adolescents: A 9-Year Temporal and Mediation Study.

CONTEXT: Surrogate measures of childhood and adolescent obesity have impaired the understanding of body composition's relationship with insulin resistance in the young population. OBJECTIVES: We aim to examine the longitudinal associations of directly measured total fat mass, trunk fat mass, and lean mass with the risk of hyperglycaemia, hyperinsulinemia, and insulin resistance from ages 15-24 years, the mediation path through which lipids and inflammation influence insulin resistance and whether increased fat mass temporally precede insulin resistance. METHODS: We studied 3160 adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC), UK birth cohort, who had complete dual-energy Xray absorptiometry measure and fasting blood samples at age 15 years and repeated measures at ages 17- and 24-years clinic visit. Fasting glucose >6.1 mmol/L, insulin >11.78 mU/L, and homeostatic model assessment for insulin resistance (HOMA-IR) ≥75th percentile were categorized as hyperglycaemia, hyperinsulinemia, and high insulin resistance, respectively. Longitudinal associations were examined with generalized logit-mixed effect models, whilst mediation and temporal path analyses were examined using structural equation models, adjusting for cardiometabolic and other lifestyle factors. RESULTS: Among 3160 participants (51% female), fat mass and lean mass increased linearly in both males and females while glucose, insulin, and HOMA-IR had a U-shaped course from age 15 through 24 years. After full adjustment, each 1 kg cumulative increase in total fat mass [odds ratio 1.12 (95% confidence interval 1.11-1.13)] and trunk fat mass [1.21 (1.19-1.23)] from ages 15 through 24 years were associated with a progressively worsening risk of high insulin resistance as well as hyperglycaemia and hyperinsulinemia. The association of increased total fat mass with increased insulin resistance was partly mediated by triglycerides (9% mediation). In the temporal path analysis, higher total fat mass at age 15 years was associated with higher insulin resistance at 17 years, but not vice versa. Higher total fat mass at 17 years was bi-directionally associated with higher insulin resistance at 24 years. CONCLUSION: Mid-adolescence may be an optimal time for interrupting the worsening fat mass-insulin resistance pathologic cycle and attenuating the risk of progressively worsening metabolic dysfunction before young adulthood.

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.

Association of stigma, diabetes distress and self-efficacy with quality of life in adolescents with type 1 diabetes preparing to transition to adult care.

AIMS: In type 1 diabetes (T1D), psychosocial factors may impact quality of life (QOL) and clinical outcomes, but remain understudied, particularly during late adolescence. Our aim was to determine whether stigma, diabetes distress and self-efficacy are associated with QOL in adolescents with T1D as they are preparing to transition to adult care. METHODS: We conducted a cross-sectional study of adolescents (ages 16-17 years) with T1D participating in the Group Education Trial to Improve Transition (GET-IT) in Montreal, Canada. Participants completed validated questionnaires on stigma using the Barriers to Diabetes Adherence (BDA) stigma subscale, self-efficacy (Self-Efficacy for Diabetes Self-Management Measure [SEDM], score 1-10), diabetes distress (Diabetes Distress Scale for Adults with type 1 diabetes) and QOL (Pediatric Quality of Life Inventory [PedsQL] 4.0 Generic Core Scale and PedsQL 3.2 Diabetes Module). We examined associations of stigma, diabetes distress and self-efficacy with QOL using multivariate linear regression models adjusted for sex, diabetes duration, socioeconomic status and HbA1c. RESULTS: Of 128 adolescents with T1D, 76 (59%) self-reported having the diabetes-related stigma and 29 (22.7%) reported experiencing diabetes distress. Those with stigma had lower diabetes-specific and general QOL scores compared with those without stigma, and stigma and diabetes distress were both associated with lower diabetes-specific QOL and lower general QOL. Self-efficacy was associated with higher diabetes-specific and general QOL. CONCLUSIONS: Stigma and diabetes distress are associated with lower QOL, whereas self-efficacy is associated with higher QOL in adolescents with T1D preparing to transfer to adult care.

Diabetes duration, perceived comfort with self-management and glycaemic control in adolescents with type 1 diabetes: A cross-sectional study.

AIMS: Evidence is lacking on whether diabetes duration is associated with type 1 diabetes (T1D) self-management during late adolescence before transfer from paediatric to adult care. We examined associations of diabetes duration with dimensions of perceived comfort with diabetes self-management (self-efficacy, transition readiness, diabetes distress) and glycaemic control in late adolescence. METHODS: Using a cross-sectional design, we conducted a secondary analysis of baseline data of adolescents (ages 16-17 years) with T1D followed at paediatric diabetes academic hospitals in Montreal and enrolled in the Group Education Trial to Improve Transition (GET-IT-T1D). Participants completed validated questionnaires on self-efficacy (Self-Efficacy for Diabetes Self-Management Measure [SEDM], score 1 to 10), diabetes distress and transition readiness, as well as a haemoglobin (HbA1c) capillary blood test. Our primary outcome was self-efficacy. We examined associations of diabetes duration with self-efficacy, diabetes distress, transition readiness and HbA1c using linear and logistic regression models adjusted for sex, socioeconomic status, insulin pump use, glucose sensor use and psychiatric comorbidity. RESULTS: Of 203 adolescents with T1D, mean diabetes duration (SD) was 7.57 (4.44) years. Mean SEDM score was 6.83 (SD 1.62). Diabetes duration was not associated with self-efficacy, diabetes distress or transition readiness. Each additional year of diabetes duration was associated with 0.11% (95% CI, 0.05 to 0.16) higher HbA1c. CONCLUSIONS: Although diabetes duration is not associated with dimensions of perceived comfort with diabetes self-management, adolescents with longer diabetes duration are at risk for higher HbA1c and may need additional support to improve glycaemic control before transition to adult care.

Supporting and Incentivizing Peer Leaders for an Internet-Based Private Peer Community for Youths With Type 1 Diabetes: Social Network and Directed Content Analysis.

BACKGROUND: Youths with type 1 diabetes (T1D) frequently experience stigma. Internet-based peer communities can mitigate this through social support but require leaders to catalyze exchange. Whether nurturing potential leaders translates into a central role has not been well studied. Another issue understudied in such communities is lurking, the viewing of exchanges without commenting or posting. OBJECTIVE: We aimed to assess the centrality of the peer leaders we selected, trained, and incentivized within the Canadian Virtual Peer Network (VPN)-T1D. This is a private Facebook (Meta Platforms, Inc) group that we created for persons aged 14 to 24 years with T1D. We specifically sought to (1) compare a quantitative estimate of network centrality between peer leaders and regular members, (2) assess the proportions of network exchanges that were social support oriented, and (3) assess proportions of high engagement (posts, comments, reactions, and votes) and low engagement (lurking) exchanges. METHODS: We recruited peer leaders and members with T1D from prior study cohorts and clinics. We trained 10 leaders, provided them with a monthly stipend, and encouraged them to post on the private Facebook group we launched on June 21, 2017. We extracted all communications (posts, messages, reactions, polls, votes, and views) that occurred until March 20, 2020. We calculated each member's centrality (80% of higher engagement communications comprising posts, comments, and reactions plus 20% of members with whom they connected). We divided each member's centrality by the highest centrality to compute the relative centrality, and compared the mean values between leaders and members (linear regression). We calculated the proportions of communications that were posts, comments, reactions, and views without reaction. We performed content analysis with a social support framework (informational, emotional, esteem-related, network, and tangible support), applying a maximum of 3 codes per communication. RESULTS: VPN-T1D gained 212 regular members and 10 peer leaders over 33 months; of these 222 members, 26 (11.7%) exited. Peer leaders had 10-fold higher relative centrality than regular members (mean 0.53, SD 0.26 vs mean 0.04, SD 0.05; 0.49 difference; 95% CI 0.44-0.53). Overall, 91.4% (203/222) of the members connected at least once through posts, comments, or reactions. Among the 75,051 communications, there were 5109 (6.81%) posts, comments, and polls, 6233 (8.31%) reactions, and 63,709 (84.9%) views (lurking). Moreover, 54.9% (3430/6253) of codes applied were social support related, 66.4% (2277/3430) of which were informational (eg, insurance and travel preparation), and 20.4% (699/3430) of which were esteem related (eg, relieving blame). CONCLUSIONS: Designating, training, and incentivizing peer leaders may stimulate content exchange and creation. Social support was a key VPN-T1D deliverable. Although lurking accounted for a high proportion of the overall activity, even those demonstrating this type of passive participation likely derived benefits, given that the network exit rate was low. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/18714.

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.

Comparison of Intranasal and Injectable Glucagon Administration Among Pediatric Population Responders.

Aims: Ease of use and acceptability of nasal versus injectable glucagon (IG) among pediatric responders have been little investigated. This study compared the performance of administering nasal and IG in parents of youth with type 1 diabetes (T1D) and in school workers. Enablers and barriers associated with each glucagon and preferred glucagon administration learning modality were also evaluated. Methods: Three months after watching short pedagogical videos, 30 parents and 30 school workers performed simulated scenarios where they administered both glucagon. Completion time and successful execution of critical steps were collected. Interviews assessed preferred learning modalities, barriers, and enablers associated with each glucagon. Results: Both groups administered nasal glucagon faster than IG (median [interquartile range]: parents 19 [12-29] vs. 97 [71-117] s, P < 0.001; school workers 24 [16-33] vs. 129 [105-165] s, P < 0.001). A lower proportion of participants successfully executed all critical steps for injectable versus nasal glucagon (significant difference for school workers [53% vs. 90%; P = 0.007] but not for parents [68% vs. 83%; P = 0.227]). Nasal glucagon was preferred for ease of use and acceptability. Preferred learning modalities were a combination of videos and workshops, but videos alone could suffice for nasal glucagon. Conclusions: Nasal glucagon is faster to use, more likely to be successfully administered, and more acceptable than IG for parents of children with T1D and school workers. Nasal glucagon training with videos could improve school workers' involvement in severe hypoglycemia management. Clinical Trial number, URL to the registration: NCT05395000, https://clinicaltrials.gov/ct2/show/NCT05395000.

Trajectories of cardiorespiratory fitness from childhood to adolescence: Findings from the QUALITY cohort.

Estimate the shape and number of cardiorespiratory fitness (CRF) trajectories from childhood to adolescence; and verify whether CRF trajectory membership can be predicted by sex, biological maturation, body weight, body composition and physical activity (PA) in childhood. Data from QUALITY were used. Participants attended baseline (8-10 y old, n = 630) and follow-ups 2 years (n = 564) and 7 years (n = 359) after baseline. Group-based trajectory analysis for relative peak oxygen consumption (VO2peak, ml·kg-1·min-1) was performed. A multinomial logistic regression model was used to estimate the associations between baseline predictors and trajectory membership. Mean age of the 454 participants was 9.7 ± 0.9 years at baseline. Three distinct VO2peak trajectories were identified and all tended to decrease. They were labelled according to the starting point and slope. High-Decreasers were mostly boys, had lower body weight and fat-free mass index and higher PA levels at baseline (p < 0.05). Female sex and higher weight were associated with higher odds of being classified in the Low-Decreaser trajectory (OR = 74.03, 95%CI = 27.06-202.54; OR = 1.48, 95%CI = 1.36-1.60). Those with higher PA were less likely to be Low-Decreasers (OR = 0.96, 95%CI = 0.94-0.97). Sex, body weight and PA in childhood are important influencing factors of VO2peak (ml·kg-1·min-1) trajectories across adolescence.

Severe obesity and global developmental delay in preschool children: Findings from a Canadian Paediatric Surveillance Program study.

Background: The co-presentation of severe obesity (SO) and global developmental delay (GDD) in Canadian preschool children has not been examined. However, SO and GDD may require syndromic diagnoses and unique management considerations. Objectives: To determine (1) minimum incidence; (2) age of onset and risk factors; and (3) health care utilization for co-presenting SO and GDD. Methods: Through the Canadian Paediatric Surveillance Program (CPSP), a monthly form was distributed to participants from February 2018 to January 2020 asking for reports of new cases of SO and GDD among children ≤5 years of age. We performed descriptive statistics for quantitative questions and qualitative content analysis for open-ended questions. Results: Forty-seven cases (64% male; 51% white; mean age: 3.5 ± 1.2 years) were included. Age of first weight concern was 2.5 ± 1.3 years and age of GDD diagnosis was 2.7 ± 1.4 years. Minimum incidence of SO and GDD was 3.3 cases per 100,000 for ≤5 years of age per year. Identified problems included school and/or behavioural problems (n = 17; 36%), snoring (n = 14; 30%), and asthma/recurrent wheeze (n = 10; 21%). Mothers of 32% of cases (n = 15) had obesity and 21% of cases (n = 10) received neonatal intensive care. Microarray was ordered for 57% (n = 27) of children. A variety of clinicians and services were accessed. As reported by CPSP participants, challenges faced by families and health service access were barriers to care. Conclusion: Children with SO and GDD have multiple comorbidities, and require early identification and referral to appropriate services. These cases may also benefit from additional testing to rule out known genetic obesity syndromes.

Text message-based intervention, Keeping in Touch (KiT), to support youth as they transition to adult type 1 diabetes care: a protocol for a multisite randomised controlled superiority trial.

INTRODUCTION: Transition from paediatric to adult care can be challenging for youth living with type 1 diabetes (T1D), as many youth feel unprepared to transfer to adult care and are at high risk for deterioration of glycaemic management and acute complications. Existing strategies to improve transition experience and outcomes are limited by cost, scalability, generalisability and youth engagement. Text messaging is an acceptable, accessible and cost-effective way of engaging youth. Together with adolescents and emerging adults and paediatric and adult T1D providers, we co-designed a text message-based intervention, Keeping in Touch (KiT), to deliver tailored transition support. Our primary objective is to test the effectiveness of KiT on diabetes self-efficacy in a randomised controlled trial. METHODS AND ANALYSIS: We will randomise 183 adolescents with T1D aged 17-18 years within 4 months of their final paediatric diabetes visit to the intervention or usual care. KiT will deliver tailored T1D transition support via text messages over 12 months based on a transition readiness assessment. The primary outcome, self-efficacy for diabetes self-management, will be measured 12 months after enrolment. Secondary outcomes, measured at 6 and 12 months, include transition readiness, perceived T1D-related stigma, time between final paediatric and first adult diabetes visits, haemoglobin A1c, and other glycaemia measures (for continuous glucose monitor users), diabetes-related hospitalisations and emergency department visits and the cost of implementing the intervention. The analysis will be intention-to-treat comparing diabetes self-efficacy at 12 months between groups. A process evaluation will be conducted to identify elements of the intervention and individual-level factors influencing implementation and outcomes. ETHICS AND DISSEMINATION: The study protocol version 7 July 2022 and accompanying documents were approved by Clinical Trials Ontario (Project ID: 3986) and the McGill University Health Centre (MP-37-2023-8823). Study findings will be presented at scientific conferences and in peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT05434754.

Associations of Diabetes-related and Health-related Quality of Life With Glycemic Levels in Adolescents With Type 1 Diabetes Preparing to Transition to Adult Care.

OBJECTIVES: As adolescents with type 1 diabetes (T1D) progress to adulthood, they assume responsibility for diabetes self-management while dealing with competing life demands, decreasing parental support, and the transfer to adult care. Lower perceived quality of life (QOL) may hamper diabetes management, which is associated with suboptimal glycemic levels. Our objective was to determine associations of diabetes- and health-related QOL with glycemic management (glycated hemoglobin [A1C]) in adolescents with T1D before their transfer to adult care. METHODS: We conducted a cross-sectional analysis of baseline data from the Group Education Trial to Improve Transition (GET-IT- T1D) in adolescents with T1D (16 to 17 years of age). Participants completed validated questionnaires measuring diabetes-related QOL (PedsQL 3.2 Diabetes Module) and health-related QOL (PedsQL 4.0 Generic Core Scales). Associations of QOL Total and subscale scores with A1C were assessed using linear regression models adjusted for sex, diabetes duration, socioeconomic status, insulin pump use, and mental health comorbidity. RESULTS: One hundred fifty-three adolescents with T1D were included (mean age, 16.5 [standard deviation, 0.3] years). Diabetes-related QOL Total scores (adjusted ß=-0.04; 95% confidence interval [CI], -0.05 to -0.02) as well as subscale scores for Diabetes Symptoms (adjusted ß=-0.02; 95% CI, -0.04 to -0.00) and Diabetes Management (adjusted ß=-0.04; 95% CI, -0.05 to -0.02) were inversely associated with A1C. Health-related QOL Total scores were not associated with A1C, but Psychosocial Health subscale scores were (adjusted ß=-0.01; 95% CI, -0.03 to -0.00). CONCLUSION: Our results suggest that strategies focussing on diabetes-related QOL and psychosocial health may help prepare adolescents for the increasing responsibility of diabetes self-care.

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.

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.

Determinants of mechanical efficiency trajectories from childhood to adolescence: Findings from the QUALITY cohort.

PURPOSE: To estimate the shape and number of mechanical efficiency (ME) trajectories from childhood to adolescence; and verify whether ME trajectory membership can be predicted by sex, biological maturation, body weight, body composition and physical activity (PA) in childhood. METHODS: Data from QUALITY, an ongoing cohort study on the natural history of obesity, were used. Participants attended a baseline visit (8-10 years, n = 630) and follow-up visits two years (n = 564), and seven years (n = 377) later. ME was assessed by an incremental cycling test at 50w (ME50w, %) and at VO2peak (MEVO2peak, %). Group-based trajectory analysis for ME and a logistic regression were performed. RESULTS: Mean age of the 454 participants (boys = 54%) was 9.7 ± 0.9 years at baseline. Two distinct ME50w trajectories were identified and all tended to decrease. No distinct trajectories emerged for MEVO2peak; average MEVO2peak increased over time. Thus, the difference between MEVO2peak (∆) at baseline and follow-up was calculated for correlation analysis. Trajectory groups were labeled "Low-Decreaser" and "High-Decreaser" (Reference) for ME50w, describing the starting point and slope. High-Decreasers were mostly prepubertal girls, had lower body weight and fat free mass index, lower PA and lower VO2peak at baseline (χ2or t-test, p < 0.05). Girls were less likely to be Low-Decreasers (OR = 0.56, 95%CI = 0.42-0.74), while having overweight/obesity predicted a greater likelihood of classification in the Low-Decreaser trajectory (OR = 2.38, 95%CI = 1.16-4.88). Those with higher PA were more likely to be Low-Decreasers (OR = 1.02, 95%CI = 1.01-1.04). Finally, concerning MEVO2peak, sex, biological maturation, body weight, zBMI, fat free mass index, PA and VO2peak were positively correlated with ∆ MEVO2peak. CONCLUSIONS: We found evidence that excess weight at baseline predicts low levels of ME in childhood and adolescence. Additionally, higher PA at baseline is not related to higher ME50w levels. More research is needed to identify different approaches to explore this measure in transition to adulthood.

The Detection, Evaluation, and Management of Dyslipidemia in Children and Adolescents: A Canadian Cardiovascular Society/Canadian Pediatric Cardiology Association Clinical Practice Update.

Atherosclerosis begins in youth and is directly linked with the presence and severity of cardiovascular risk factors, including dyslipidemia. Thus, the timely identification and management of dyslipidemia in childhood might slow atherosclerotic progression and decrease the risk of cardiovascular disease in adulthood. This is particularly true for children with genetic disorders resulting in marked dyslipidemia, including familial hypercholesterolemia, which remains frequently undiagnosed. Universal and cascade screening strategies can effectively identify cases of pediatric dyslipidemia. In the clinical evaluation of children with dyslipidemia, evaluating for secondary causes of dyslipidemia, including medications and systemic disorders is essential. The first line therapy generally centres around lifestyle modifications, with dietary changes specific to the dyslipidemia phenotype. Indications for medication depend on the severity of dyslipidemia and an individualized assessment of cardiovascular risk. Despite an expanding evidence base supporting the detection and timely management of pediatric dyslipidemia, numerous knowledge gaps remain, including a sufficient evidence base to support more widespread screening, thresholds for initiation of pharmacotherapy, and treatment targets. Further studies on the most appropriate age for statin initiation and long-term safety studies of statin use in youth are also required. The most pressing matter, however, is the development of knowledge translation strategies to improve the screening and detection of lipid disorders in Canadian youth.

Comparison of different severe obesity definitions in predicting future cardiometabolic risk in a longitudinal cohort of children.

OBJECTIVES: Severe obesity (SO) prevalence varies between reference curve-based definitions (WHO: ≥99th percentile, Centers for Disease Control and Prevention (CDC): >1.2×95th percentile). Whether SO definitions differentially predict cardiometabolic disease risk is critical for proper clinical care and management but is unknown. DESIGN: Prospective cohort study SETTING: SO definitions were applied at baseline (2005-2008, Mage=9.6 years, n=548), and outcomes (fasting lipids, glucose, homoeostatic model assessment (HOMA-IR) and blood pressure) were assessed at first follow-up (F1: 2008-2011, Mage=11.6 years) and second follow-up (2015-2017, Mage=16.8 years) of the Quebec Adipose and Lifestyle Investigation in Youth cohort in Montreal, Quebec. PARTICIPANTS: Respondents were youth who had at least one biological parent with obesity. PRIMARY OUTCOME MEASURES: Unfavourable cardiometabolic levels of fasting blood glucose (≥6.1 mmol/L), insulin resistance (HOMA-IR index ≥2.0), high-density lipoprotein <1.03 mmol/L, low-density lipoprotein ≥2.6 mmol/L and triglycerides >1.24 mmol/L. Unfavourable blood pressure was defined as ≥90th percentile for age-adjusted, sex-adjusted and height-adjusted systolic or diastolic blood pressure. ANALYSIS: Area under the receiver operating characteristic curve (AUC) and McFadden psuedo R2 for predicting F1 or F2 unfavourable cardiometabolic levels from baseline SO definitions were calculated. Agreement was assessed with kappas. RESULTS: Baseline SO prevalence differed (WHO: 18%, CDC: 6.7%). AUCs ranged from 0.52 to 0.77, with fair agreement (kappa=37%-55%). WHO-SO AUCs for detecting unfavourable HOMA-IR (AUC>0.67) and high-density lipoprotein (AUC>0.59) at F1 were statistically superior than CDC-SO (AUC>0.59 and 0.53, respectively; p<0.05). Only HOMA-IR and the presence of more than three risk factors had acceptable model fit. WHO-SO was not more predictive than WHO-obesity, but CDC-SO was statistically inferior to CDC-obesity. CONCLUSION: WHO-SO is statistically superior at predicting cardiometabolic risk than CDC-SO. However, as most AUCs were generally uninformative, and obesity definitions were the same if not better than SO, the improvement may not be clinically meaningful.

Social support and C-reactive protein in a Québec population cohort of children and adolescents.

OBJECTIVE: Robust evidence exists for the health-enhancing benefits of social support in adults. Inflammatory processes are thought to be an important mechanism linking social support and health risk. Less is known about the relation between social support and chronic inflammation during childhood and adolescence, or when the association emerges during the lifespan. METHOD: Data from the population-representative 1999 Quebec Child and Adolescent Health and Social (QCAHS) survey were analyzed. Youth aged 9, 13, and 16 years (N = 3613) and their parents answered questions about social support. A subsample (n = 2186) completed a fasting blood draw that was assayed for C-reactive protein (CRP). FINDINGS: Higher social support was significantly associated with lower hs-CRPlog, after controlling for age, sex, body mass index (BMI Z-score), medication use, puberty, ethnoracial status (French-Canadian), smoking, household income, and parental education (F = 25.88, p = < .001, Total R2adj = 10.2%). The association was largely similar for boys and girls, and strengthened with age. CONCLUSION: Greater social support was linked to lower chronic low-grade inflammation in a large sample of children and adolescents. Effect sizes were small and consistent with prior findings in the adult literature. Importantly, these findings provide evidence that the relation between social support and inflammation emerges early in the lifespan. Future work should consider broader, more encompassing conceptualizations of social support, the role of social media, and prospective trajectories of social support and inflammatory markers.