Exploring the association between internalized weight bias and mental health among Canadian adolescents.

BACKGROUND: Internalized weight bias (IWB) has been identified as a correlate of higher depressive and anxiety symptoms in adolescents with higher weights. However, there has been limited investigation into how IWB relates to positive mental health and whether these associations differ across genders. OBJECTIVES: To examine the associations between IWB and mental health (depression, anxiety, flourishing) in adolescents with higher weights, and to test the potential moderating role of gender. METHODS: Canadian adolescents with higher weights (N = 7538, 60% boys, 36% girls, 4% gender diverse, ages 12-19) from the COMPASS study completed a survey during the 2021-2022 school year. Data were analysed using generalized linear models. RESULTS: Highest IWB and poorest mental health were noted within gender diverse adolescents, followed by girls then boys. Gender moderated the relationship between higher IWB and higher depression, higher anxiety and lower flourishing, with the strongest relationships noted among girls. CONCLUSION: IWB interventions should be tailored to gender subgroups that may be particularly vulnerable to maladaptive mental health outcomes associated with IWB. System-level changes that mitigate perpetuation of weight bias and discrimination which lead to IWB are also essential, particularly for girls.

Screening for depression in children and adolescents in primary care or non-mental health settings: a systematic review update.

BACKGROUND: The transition from childhood to adolescence is associated with an increase in rates of some psychiatric disorders, including major depressive disorder, a debilitating mood disorder. The aim of this systematic review is to update the evidence on the benefits and harms of screening for depression in primary care and non-mental health clinic settings among children and adolescents. METHODS: This review is an update of a previous systematic review, for which the last search was conducted in 2017. We searched Ovid MEDLINE® ALL, Embase Classic+Embase, PsycINFO, Cochrane Central Register of Controlled Trials, and CINAHL on November 4, 2019, and updated on February 19, 2021. If no randomized controlled trials were found, we planned to conduct an additional search for non-randomized trials with a comparator group. For non-randomized trials, we applied a non-randomized controlled trial filter and searched the same databases except for Cochrane Central Register of Controlled Trials from January 2015 to February 2021. We also conducted a targeted search of the gray literature for unpublished documents. Title and abstract, and full-text screening were completed independently by pairs of reviewers. RESULTS: In this review update, we were unable to find any randomized controlled studies that satisfied our eligibility criteria and evaluated the potential benefits and harms of screening for depression in children and adolescents. Additionally, a search for non-randomized trials yielded no studies that met the inclusion criteria. CONCLUSIONS: The findings of this review indicate a lack of available evidence regarding the potential benefits and harms of screening for depression in children and adolescents. This absence of evidence emphasizes the necessity for well-conducted clinical trials to evaluate the effectiveness of depression screening among children and adolescents in primary care and non-mental health clinic settings. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020150373 .

Sleep and insulin sensitivity in adolescents at risk of type 2 diabetes: the Sleep Manipulation in Adolescents at Risk of Type 2 Diabetes (SMART2D)randomized crossover study.

STUDY OBJECTIVES: To investigate the effect of increasing sleep duration for 1 week, compared to a week of habitual and decreased sleep, on insulin sensitivity(IS) in adolescents at risk for type 2 diabetes(T2D). METHODS: Adolescents, 13-18y old, at risk for T2D, with obesity and other risk factors, were recruited for a randomized(1:1), open-label, sex-stratified crossover study, that manipulated time-in-bed to modify sleep duration (measured by actigraphy). Following a week of habitual(HB) sleep, time-in-bed was increased(IN) and decreased(DE) by 1h30min/night for 1 week, counterbalanced across participants(HBINDE or HBDEIN), and separated by a week of washout sleep. The main outcome measure was IS, obtained via 2-h oral-glucose-tolerance-test conducted after each sleep week. RESULTS: Of the 43 participants recruited, 36(84%) completed all sleep interventions (52.8% female, age=15.1y, body-mass-index=99.9th percentile, order: HBINDE=18 and HBDEIN=18). On average, during the HB week, participants slept 7h31min/night; sleep duration was 1h02min/night higher during the IN week and 1h19min/night lower during the DE week. We found a significant effect of sleep week on IS with a large effect size. Following the IN sleep week, IS was 20% higher compared to after the HB and DE sleep weeks, but there was no significant difference in IS following HB versus DE sleep weeks. CONCLUSION: Whenever possible, clinicians should empower youth at risk of T2D to improve their sleep duration, since even a modest increase in sleep duration of 1h/night for one-week can have a positive impact on IS in this population.

Teaching Adolescents With Type 1 Diabetes Self-Compassion (TADS) to Reduce Diabetes Distress: Protocol for a Randomized Controlled Trial.

BACKGROUND: Adolescents living with type 1 diabetes (T1D) often experience diabetes distress (DD), a construct distinct from depression or anxiety that refers to the negative emotions that arise from living with and managing diabetes. Self-compassion, which involves being open to one's own suffering and treating oneself with the same care one would show to loved ones, is associated with better psychological and clinical outcomes among individuals with T1D. Self-compassion is a skill that can be taught and therefore represents an opportunity for intervention. OBJECTIVE: The overall aim of this study is to assess the effectiveness of a web-based mindful self-compassion for teens (MSC-T) intervention on improving DD, anxiety, depression, diabetes-related disordered eating, and suicidal ideation experienced by youth with T1D (aged between 12 and 17 years) compared with a waitlist control group (standard of care). We will also explore (1) if the effect of the MSC-T intervention changes over time, (2) if the MSC-T intervention has a positive impact on measures of glycemic control, and (3) if the effect of the MSC-T intervention differs based on self-reported gender. METHODS: We will conduct a single-center, parallel-group randomized controlled trial of 140 adolescents with T1D followed for 12 months. Participants will be randomly allocated (using hidden allocation) in a 1:1 ratio to either the MSC-T intervention or the waitlist control group. Our primary outcome is DD, as measured by the Problem Areas in Diabetes-Teen (PAID-T) version at 3 months. Secondary outcomes, assessed at 3 and 12 months, include anxiety (Generalized Anxiety Disorder 7-item [GAD-7] scale), depression (Patient Health Questionnaire-9 [PHQ-9]), diabetes-related disordered eating (Diabetes Eating Problem Survey-Revised [DEPS-R] version), and suicidal ideation (using 1 question from the PHQ-9). RESULTS: Study recruitment began in October 2022 and was completed in March 2023, with a total of 141 participants enrolling. Data collection will be ongoing until March 2024. The first results are expected in June 2024. CONCLUSIONS: This study will be the first randomized trial to assess the effectiveness of the web-based MSC-T intervention on adolescents with T1D. Given that adolescence is a period where individuals are typically required to assume more responsibility for their diabetes care, providing adolescents with the tools they need to better manage the stress that often accompanies T1D management is paramount. TRIAL REGISTRATION: ClinicalTrials.gov NCT05463874; https://clinicaltrials.gov/study/NCT05463874. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/53935.

Elevations in serum brain-derived neurotrophic factor following occupational heat stress are not influenced by age or common chronic disease.

With global warming, workers are increasingly exposed to strenuous occupations in hot environments. Given age- and disease-associated declines in thermoregulatory function, older workers are at an elevated risk of developing heat-related injuries. Brain-derived neurotrophic factor (BDNF) is thought to confer neuroprotection during acute exercise, however, the influence of environmental heat on BDNF responses during prolonged work remains unclear. Therefore, we evaluated serum BDNF concentrations before and after 180 min of moderate-intensity treadmill walking (200 W/m2) and after 60 min of post-exercise recovery in temperate (wet-bulb globe temperature (WBGT) 16°C) and hot (WBGT 32°C) environments in 13 healthy young men (mean [SD; 22 [3] years), 12 healthy older men (59 [4] years), 10 men with hypertension (HTN) (60 [4] years), and 9 men with type 2 diabetes (T2D) (60 [5] years). In the temperate condition, all but one participant (1 HTN) completed the 180 min of exercise. While exercise tolerance in the heat was lower in older men with HTN (117 min [45]) and T2D (123 min [42]) compared to healthy older men (159 min [31]) (both p ≤ 0.049), similar end-exercise rectal temperatures (38.9°C [0.4]) were observed across groups, paralleled by similar elevations in serum BDNF across groups at end-exercise (+1106 pg/mL [203]) and end-recovery (+938 pg/mL [146]; all p ≤ 0.01) in the heat. No changes in serum BDNF were observed in the temperate condition. Our findings indicate similar BDNF responses in individuals with HTN or T2D compared to their healthy counterparts, despite exhibiting reduced tolerance to heat.

Heavy social media use and psychological distress among adolescents: the moderating role of sex, age, and parental support.

Background: Despite increasing evidence that social media use is associated with adolescents' mental well-being, little is known about the role of various factors in modifying the effect of this association during adolescence. This study examined the association between social media use and psychological distress among adolescents and explored whether sex, age, and parental support moderate this association. Methods: Data came from a representative sample of middle and high school students in Ontario, Canada. Cross-sectional analyses included 6,822 students derived from the 2019 Ontario Student Drug Use and Health Survey. Results: Our results showed that 48% of adolescents used social media for 3 h or more per day, and 43.7% had moderate to severe psychological distress, with a higher prevalence among females (54%) than males (31%). After adjustment for relevant covariates, heavy social media use (≥3 h/day) was associated with increased odds of severe psychological distress [odds ratio (OR): 2.01; 95% confidence interval (CI):1.59-2.55]. The association of social media use with psychological distress was modified by age (p < 0.05) but not sex or parental support. The association was stronger among younger adolescents. Conclusion: Heavy social media use is associated with higher levels of psychological distress, with younger adolescents being the most vulnerable. Longitudinal studies are recommended for future research to examine in more depth the role of sex, age, and parental support in the association between social media use and psychological distress to better determine the strength and of the association.

Loneliness during COVID-19 and its association with eating habits and 24-hour movement behaviours in a sample of Canadian adolescents.

Loneliness, a feeling of distress, has aggravated due to the COVID-19 pandemic lockdowns and reduced social interactions. The objective of this study was to explore whether increased loneliness due to the COVID-19 pandemic was associated with various health behaviours in adolescence, a critical period for the development of lasting lifestyle habits. We used self-reported data from 40,521 Canadian adolescents aged 12-19 years (collected between November 2020 and June 2021) for this cross-sectional study. Logistic regression was used to predict the odds of skipping breakfast and not meeting movement behaviour guidelines [moderate-to-vigorous physical activity (≥60 min/day), recreational screen time (≤2 h/day), sleep duration (≥8 h/day)] among adolescents with increased loneliness due to the COVID-19 pandemic. We found higher odds of skipping breakfast [boys: OR 1.40 (95% CI: 1.32, 1.49), girls: OR 1.62 (95% CI: 1.53, 1.71)], exceeding screen time guidelines [boys: OR 1.43 (95% CI: 1.24, 1.66), girls: OR 1.72 (95% CI: 1.54, 1.92)], and insufficient sleep duration [boys: OR 1.38 (95% CI: 1.28, 1.48), girls: OR 1.36 (95% CI: 1.27, 1.45)] in adolescents with increased loneliness (versus decreased/stayed the same loneliness group). However, we found clinically insignificant results with moderate-to-vigorous physical activity. Future longitudinal studies in adolescents are needed to confirm the directionality of these associations. Recovery efforts are needed to support adolescent social health and establish healthy behavioural habits across the lifespan.

Longitudinal associations between different types of screen use and depression and anxiety symptoms in adolescents.

Background: Evidence examining the longitudinal associations between different types of screen behaviours and mental health among adolescents is limited. The present study examined the association between five types of screen behaviours and symptoms of anxiety and depression one year later. This study also assessed how changes in screen time were associated with changes in anxiety and depressive symptoms and whether the observed relationships were moderated by sex. Methods: Longitudinal data of 17,174 students in grades 9-12 (53.5% females; mean age: 15.1 ± 0.9 years) attending high schools in Canada from two waves (year 6: 2017/18, year 7: 2018/19) of the COMPASS study were analyzed. Leisure screen time and mental health measures were self-reported. To test if the associations between screen time and anxiety, and depression vary by sex, two-way interactions were examined for sex. Analyses accounted for school clustering, race/ethnicity, sex, age, income, body mass index z-score, and previous year anxiety and depression symptoms. Results: There were significant longitudinal associations between time spent on each type of screen and subsequent anxiety and depression symptoms. The strength of the associations varied by type of screen behaviour. Interaction analysis indicated a sex difference for television viewing and anxiety and depression symptoms, and internet surfing and anxiety symptoms. A dose-response relationship was observed between phone talking and anxiety symptoms. Beta estimates indicated that an increase in screen duration was associated with a further increase in anxiety and depression symptoms. Conclusion: Higher screen time was longitudinally associated with higher anxiety and depression symptoms at one-year follow-up in adolescents. Time-change associations between screen usage and depressive and anxiety symptoms were observed. Also, associations differed based on sex and screen type, whereby greater increases in screen use predicted greater emotional distress. Findings from this prospective analysis suggest that screen time is an important determinant of anxiety and depressive symptoms among adolescents. Future studies are recommended to help inform programs promoting screen time reduction with a goal to enhance adolescents' mental health.

No association of the dopamine D2 receptor genetic bilocus score (rs1800497/rs1799732) on food addiction and food reinforcement in Chilean adults.

Purpose: Different systems regulate food intake. In the reward system, dopamine (DA) is the main neurotransmitter, and a variety of genetic variants (rs1799732 and rs1800497) are associated with addiction. Addiction is a highly polygenic disease, where each allelic variant adds a small amount of vulnerability. Polymorphisms rs1799732 and rs1800497 are associated with eating behavior and hedonic hunger, but links to food addiction remain unclear. Aim: To evaluate the association between the bilocus profile (rs1799732-rs1800497) of the dopaminergic pathway with food reinforcement and food addiction in Chilean adults. Methods: A cross-sectional study recruited a convenience sample of 97 obese, 25 overweight, and 99 normal-weight adults (18-35 years). Anthropometric measurements were performed by standard procedures and eating behavior was assessed using the: Food Reinforcement Value Questionnaire (FRVQ) and Yale Food Addiction scale (YFAS). The DRD2 genotypes were determined by TaqMan assays (rs1800497 and rs1799732). A bilocus composite score was calculated. Results: In the normal weight group, individuals who were heterozygous for the rs1977932 variant (G/del) showed higher body weight (p-value 0.01) and abdominal circumference (p-value 0.01) compared to those who were homozygous (G/G). When analyzing rs1800497, a significant difference in BMI was observed for the normal weight group (p-value 0.02) where heterozygous showed higher BMI. In the obese group, homozygous A1/A1 showed higher BMI in comparison to A1/A2 and A2/A2 (p-value 0.03). Also, a significant difference in food reinforcement was observed in the rs1800497, where homozygous for the variant (A1A1) show less reinforcement (p-value 0.01).In relation to the bilocus score in the total sample, 11% showed "very low dopaminergic signaling", 24.4% were "under", 49.7% showed "intermediate signaling", 12.7% showed "high" and 1.4% showed "very high". No significant genotypic differences were observed in food reinforcement and food addiction by bilocus score. Conclusions: The results indicate that the genetic variants rs1799732 and rs1800497 (Taq1A) were associated with anthropometric measurements but not with food addiction or food reinforcement in Chilean university students. These results suggest that other genotypes, such as rs4680 and rs6277, which affect DA signaling capacity through a multilocus composite score, should be studied. Level V: Evidence obtained from a cross-sectional descriptive study.

Effects of the HEARTY exercise randomized controlled trial on eating behaviors in adolescents with obesity.

Background: There are well-recognized benefits of behavioral interventions that include exercise for children and adolescents with obesity. However, such behavioral weight management programs may precipitate unintended consequences. It is unclear if different exercise modalities impact eating behaviors differently in youth with obesity. Objectives: The purpose of this study was to examine the effects of aerobic, resistance, and combined aerobic and resistance exercise training on eating attitudes and behaviors (uncontrolled eating, restrained eating, emotional eating, external eating and food craving) among adolescents with overweight and obesity. Methods: N = 304 (70% female) adolescents with overweight and obesity participated in the 6-month Healthy Eating Aerobic and Resistance Training in Youth (HEARTY) randomized controlled trial. All participants were inactive post-pubertal adolescents (15.6 ± 1.4 years) with a mean BMI = 34.6 ± 4.5 kg/m2. The Food Craving Inventory (food cravings), Dutch Eating Behavior Questionnaire (restrained eating, emotional eating, external eating), and the Three-Factor Eating Questionnaire (uncontrolled eating) were used to assess eating attitudes and behaviors. Results: All exercise groups showed within-group decreases in external eating and food cravings. Participants randomized to the Combined training group and were more adherent showed the greatest improvements in eating behaviors and cravings. Conclusions: A 6-month exercise intervention produced improvements in disordered eating behaviors and food cravings, but effects may be gender and modality-specific. Findings highlight the need to tailor exercise intervention to participant characteristics for the promotion of healthier eating and weight management outcomes in youth with obesity.Clinical Trial Registration # and Date: ClinicalTrials.Gov NCT00195858, September 12, 2005.

The association between social media use and physical activity among Canadian adolescents: a Health Behaviour in School-aged Children (HBSC) study.

OBJECTIVE: To determine the association between social media use (SMU) and physical activity (PA) among Canadian adolescents. METHODS: We used data from 12,358 participants in grades 6 to 10 who responded to the Canadian component of the 2017/2018 Health Behaviour in School-aged Children (HBSC) survey. Social media intensity and problematic SMU were assessed using a 4-point mutually exclusive scale that contained three categories based on intensity (non-active, active, and intense SMU) and one category based on the presence of addiction-like symptoms irrespective of intensity (problematic SMU). PA was assessed for five domains (i.e., school curriculum, organized sport, exercise, outdoor play, and active transport) and dichotomized using the first quartile to represent high PA engagement in each domain. Meeting PA recommendation of 60 min per day of moderate-to-vigorous PA was calculated using the sum of the five domains. Logistic regression models were used to assess the association between SMU and PA, with active SMU used as the reference group for all models. RESULTS: Non-active SMU was associated with lower odds of meeting the daily PA recommendations and of high engagement in all five domains of PA when compared to active SMU. Intense SMU was associated with higher odds of meeting the daily PA recommendations. Problematic SMU was not associated with meeting daily PA recommendations, but it was significantly associated with lower odds of high PA engagement in the exercise domain. CONCLUSION: The findings of this study suggest that non-active SMU was significantly associated with lower PA levels. Problematic SMU was only significantly associated with lower PA levels in the exercise domain. Intense SMU was associated with higher odds of meeting the PA recommendation.

RéSUMé: OBJECTIF: Établir la relation entre l'utilisation des médias sociaux et l'activité physique chez les adolescents canadiens. MéTHODES: Nous avons utilisé les données de 12 358 participants de la 6e à la 10e année qui ont répondu au volet canadien de l'Enquête sur les comportements de santé des jeunes d'âge scolaire de 2017­2018 (HBSC). L'intensité des médias sociaux et leur utilisation problématique ont été évaluées à l'aide d'une échelle à quatre points mutuellement exclusifs contenant trois catégories basées sur l'intensité (utilisation non active, active et intense des médias sociaux) et une catégorie basée sur la présence de symptômes de dépendance indépendamment de l'intensité (utilisation problématique des médias sociaux). L'activité physique a été évaluée pour cinq domaines (c'est-à-dire le programme scolaire, le sport organisé, l'exercice, le jeu en plein air et le transport actif) et dichotomisée en utilisant le premier quartile pour représenter la participation à une activité physique élevée dans chaque domaine. Le respect de la recommandation de 60 min par jour d'activité physique modérée à vigoureuse a été calculé en utilisant la somme des cinq domaines. Des modèles de régression logistique ont été utilisés pour évaluer la relation entre l'utilisation des médias sociaux et l'activité physique, l'utilisation active des médias sociaux étant utilisée comme groupe de référence pour tous les modèles. RéSULTATS: L'utilisation non active des médias sociaux était associée à une probabilité plus faible de respecter les recommandations en matière d'activité physique quotidienne et à une participation élevée dans les cinq domaines de l'activité physique, par rapport à l'utilisation active des médias sociaux. Une utilisation intense des médias sociaux était associée à une probabilité plus élevée de respecter les recommandations en matière d'activité physique quotidienne. Une utilisation problématique des médias sociaux n'était pas associée au respect des recommandations en matière d'activité physique quotidienne, mais elle était fortement associée à une probabilité moindre de participation élevée à une activité physique dans le domaine de l'exercice. CONCLUSION: Les résultats de cette étude suggèrent que l'utilisation non active des médias sociaux est fortement associée à des niveaux d'activité physique plus faibles. Une utilisation problématique des médias sociaux n'était fortement associée à des niveaux d'activité physique plus faibles que dans le domaine de l'exercice. Une utilisation intense des médias sociaux était associée à une probabilité plus élevée de respecter la recommandation en matière d'activité physique.

Appearance satisfaction mediates the relationship between recreational screen time and depressive symptoms in adolescents.

BACKGROUND: Research suggests there is an association between high levels of recreational screen time and depression among adolescents; however, mechanisms driving this association remain unknown. The present study examined appearance and weight satisfaction and disordered eating behaviors as mediators in the relationship between recreational screen time and depressive symptoms in adolescents. METHOD: Longitudinal data on screen time, depressive symptoms, disordered eating behaviors, and appearance and weight satisfaction from 304 adolescents (194 females, Mage = 13.40) were analyzed through a moment structure model. RESULTS: Results revealed appearance dissatisfaction mediated the direct effect of recreational screen time on depressive symptoms (Estimate = 0.48, SE = .18, 95% CI [0.12, 0.84]), and that recreational screen time was significantly related to lower appearance satisfaction (Estimate = -0.06, SE = .02, 95% CI [-0.10, -0.01]), which was significantly predictive of more severe depressive symptoms (Estimate = -1.49, SE = .62, 95% CI [-2.71, -0.28]). CONCLUSIONS: These findings suggest that modulating screen time may be an efficacious strategy to reduce appearance dissatisfaction and depressive symptoms during adolescence.

Effect of Combined Exercise Training on Physical and Cognitive Function in Women With Type 2 Diabetes.

OBJECTIVES: One of the consequences of old age is cognitive and physical decline, which can cause a wide range of problems. These complications are more pronounced in those with type 2 diabetes (T2D). The aim of this pilot study was to investigate the effect of combined exercise training on blood biomarkers, physical fitness, and cognitive function in elderly women with T2D. METHODS: Twenty-one elderly women with T2D were randomly allocated to training (n=12) and control (n=9) groups. The exercise training program was a combination of aerobic, resistance, and balance exercises performed 3 times per week over 12 weeks. In the same period, the control group received no training intervention. Blood markers, including brain-derived neurotrophic factor (BDNF), irisin, glycated hemoglobin (A1C), fasting blood sugar (FBS), cardiorespiratory fitness (CRF), lower and upper body strength, and cognitive function, were measured in all participants at baseline and after 12 weeks. RESULTS: Serum BDNF levels were not significantly different between the exercise and control groups at 12 weeks (p>0.05). FBS and A1C levels in the exercise group decreased significantly compared with the control group (p<0.05). CRF, dynamic balance, and both upper and lower body strength in the exercise group improved significantly compared with the control group (p<0.05). Irisin levels decreased significantly in the control group, but levels did not change significantly in the exercise group. Greater improvements from exercise were observed on the Montreal Cognitive Assessment index compared with the control group (p=0.05), but no other group differences in cognitive function were noted. CONCLUSIONS: Combined exercise improved some physical fitness and diabetes-related surrogate factors, as well as select cognitive functions, but had no significant effect on cognition-related biochemical factors (i.e. BDNF) in women with T2D.

The Resistance Exercise in Already Active Diabetic Individuals (READI) Randomized Clinical Trial.

CONTEXT: Resistance exercise training (strength training) and aerobic exercise training are both recommended for people with type 1 diabetes, but it is unknown whether adding resistance exercise provides incremental benefits in people with this condition who already perform aerobic exercise regularly. OBJECTIVE: This work aimed to evaluate the incremental effect of resistance training on glycated hemoglobin A1c (HbA1c), fitness, body composition, and cardiometabolic risk factors in aerobically active people with type 1 diabetes. METHODS: The Resistance Exercise in Already-active Diabetic Individuals (READI) trial (NCT00410436) was a 4-center, randomized, parallel-group trial. After a 5-week run-in period with diabetes management optimization, 131 aerobically active individuals with type 1 diabetes were randomly assigned to resistance exercise (n = 71, intervention-INT) or control (n = 60, CON) for 22 additional weeks. Both groups maintained their aerobic activities and were provided dietary counseling throughout. Exercise training was 3 times per week at community-based facilities. The primary outcome was HbA1c, and secondary outcomes included fitness (peak oxygen consumption, muscle strength), body composition (anthropometrics, dual-energy x-ray absorptiometry, computed tomography), and cardiometabolic risk markers (lipids, apolipoproteins). Assessors were blinded to group allocation. RESULTS: There were no significant differences in HbA1c change between INT and CON. Declines in HbA1c (INT: 7.75 ± 0.10% [61.2 ± 1.1 mmol/mol] to 7.55 ± 0.10% [59 ± 1.1 mmol/mol]; CON: 7.70 ± 0.11% [60.7 ± 1.2 mmol/mol] to 7.57 ± 0.11% [59.6 ± 1.3 mmol/mol]; intergroup difference in change -0.07 [95% CI, -0.31 to 0.18]). Waist circumference decreased more in INT than CON after 6 months (P = .02). Muscular strength increased more in INT than in CON (P < .001). There were no intergroup differences in hypoglycemia or any other variables. CONCLUSION: Adding resistance training did not affect glycemia, but it increased strength and reduced waist circumference, in aerobically active individuals with type 1 diabetes.

Coping in adolescents: A mediator between stress and disordered eating.

BACKGROUND: Adolescence is a developmental period that can place individuals at heightened risk of engaging in disordered eating patterns. Stress and coping have been included as etiological factors of eating pathology, yet the mechanism of this relationship in adolescent males and females remains understudied. AIMS: This study investigated the role of coping as a mediator in the stress-disordered eating relationship in a sample of adolescents. DEMOGRAPHICS/SETTINGS: Participants included 2262 grade 7-12 students from a larger cross-sectional study entitled, Research on Eating and Adolescent Lifestyles (REAL). METHODOLOGY/ANALYSES: Participants completed measures of perceived stress, life stressors, coping style, and disordered eating. Multiple mediator models of coping were analyzed to examine the extent to which coping mediated the stress-disordered eating relationship, for males and females separately. FINDINGS: Emotion-oriented coping was a significant partial mediator in the relationship between stress (perceived stress, life stressors) and disordered eating in male and female adolescents. Findings suggest adolescents experiencing high stress tend to engage in emotion-oriented coping, which may lead to greater levels of disordered eating. IMPLICATIONS: Interventions targeting effective coping strategies for dealing with different stress types may prevent youth from disordered eating, thus reducing their risk of eating disorders during a vulnerable period in development.

Interindividual Differences in Trainability and Moderators of Cardiorespiratory Fitness, Waist Circumference, and Body Mass Responses: A Large-Scale Individual Participant Data Meta-analysis.

Although many studies have assumed variability reflects variance caused by exercise training, few studies have examined whether interindividual differences in trainability are present following exercise training. The present individual participant data (IPD) meta-analysis sought to: (1) investigate the presence of interindividual differences in trainability for cardiorespiratory fitness (CRF), waist circumference, and body mass; and (2) examine the influence of exercise training and potential moderators on the probability that an individual will experience clinically important differences. The IPD meta-analysis combined data from 1879 participants from eight previously published randomized controlled trials. We implemented a Bayesian framework to: (1) test the hypothesis of interindividual differences in trainability by comparing variability in change scores between exercise and control using Bayes factors; and (2) compare posterior predictions of control and exercise across a range of moderators (baseline body mass index (BMI) and exercise duration, intensity, amount, mode, and adherence) to estimate the proportions of participants expected to exceed minimum clinically important differences (MCIDs) for all three outcomes. Bayes factors demonstrated a lack of evidence supporting a high degree of variance attributable to interindividual differences in trainability across all three outcomes. These findings indicate that interindividual variability in observed changes are likely due to measurement error and external behavioural factors, not interindividual differences in trainability. Additionally, we found that a larger proportion of exercise participants were expected to exceed MCIDs compared with controls for all three outcomes. Moderator analyses identified that larger proportions were associated with a range of factors consistent with standard exercise theory and were driven by mean changes. Practitioners should prescribe exercise interventions known to elicit large mean changes to increase the probability that individuals will experience beneficial changes in CRF, waist circumference and body mass.

Sociodemographic Factors Associated With Objectively Measured Moderate- to Vigorous-intensity Physical Activity in Adults With Type 2 Diabetes: Cross-sectional Results From the Canadian Health Measures Survey (2007 to 2017).

OBJECTIVES: Individuals with type 2 diabetes should engage in ≥150 min of moderate- to vigorous-intensity physical activity (MVPA) weekly, but most do not meet this guideline. Understanding how social determinants correlate with physical activity in adults with type 2 diabetes may improve development and delivery of physical activity interventions. This study aimed to explore associations between objectively measured MVPA with sociodemographic characteristics in adults with type 2 diabetes. METHODS: Cross-sectional data from cycles 1 through 5 of the Canadian Health Measures Survey were analyzed. Participants (N=876) 20 to 79 years of age with type 2 diabetes and ≥4 days of valid activity monitor wear were included. Proportions with 95% confidence intervals for objectively measured MVPA were compared according to sociodemographic characteristics. Ordinal logistic regression was used. Secondary outcomes included light-intensity physical activity, screen time and proportion of activity monitor wear time spent sedentary. RESULTS: Only 15.5% of women and 26.2% of men met Diabetes Canada physical activity guidelines, and approximately 75% of activity monitor wear time was spent in a sedentary state. Higher odds of achieving low levels of physical activity were observed among women who were former or current smokers (odds ratio [OR], 4.51; p<0.001), and among men who were ≥65 years of age (OR, 2.92; p<0.001), of middle (OR, 2.20; p<0.05) and lowest (OR, 3.06; p<0.05) income tertiles and current or former smokers (OR, 3.01; p<0.05). CONCLUSIONS: Sociodemographic factors are strongly associated with levels of MVPA in adults with type 2 diabetes. Sociodemographic information should be routinely collected by clinicians and used to inform more tailored and effective interventions for this patient population.

Associations between screen time and cognitive development in preschoolers.

Objectives: To examine the cross-sectional associations between screen time and cognitive development in preschoolers. Methods: Participants were 97 preschoolers (36 to 60 months) in Alberta and Ontario, Canada in the supporting Healthy physical AcTive Childcare setting (HATCH) study. The time that children spent watching television, videos or DVDs (television time) or playing video or computer games (video game time) on a television, computer, or portable device was assessed using a parental questionnaire. Television time and video game time were summed to calculate total screen time. Adherence to the screen time recommendation (≤1 hour/day) of the Canadian 24-Hour Movement Guidelines was calculated. Expressive vocabulary and working memory were assessed using the Early Years Toolbox. Due to the distribution of working memory, it was categorized as a binary variable based on the median score. The associations between screen time and cognitive development were examined using mixed models (expressive vocabulary) or generalized mixed models (working memory). Results: Screen time was not associated with expressive vocabulary. Preschoolers who had higher total screen time were less likely to have better working memory (OR=0.52; 95%CI:0.31, 0.88), despite the null associations for television time (P=0.155) and video game time (P=0.079). Preschoolers who met the screen time recommendation were more likely to have higher working memory capacity (OR=3.48; 95%CI:1.06, 11.47), compared to those who did not meet the recommendation. Conclusion: Limiting total screen time to no more than one hour per day may facilitate working memory development in preschoolers. Screen time may be unrelated to expressive language development in this age group.

The impact of new government childcare accreditation standards on children's in-care physical activity and sedentary time.

BACKGROUND: A new physical activity and sedentary behaviour accreditation standard criterion for childcare settings was introduced by the provincial government in Alberta, Canada. The primary objective of this study was to examine if changes for in-care physical activity and sedentary time (ST) differed between centres in and around Edmonton, Alberta after implementing the new accreditation standards and non-accredited control centres in and around Ottawa, Ontario. Secondary objectives were to examine whether baseline age group (toddler, preschooler) or the childcare environment moderated any group differences in change of the primary outcomes. Furthermore, accreditation and control group differences in change of children's body mass index (BMI) Z-scores or cognitive development as well as educators' perceptions of the primary outcomes were explored. METHODS: Participants were 252 toddlers (19-35 months) and preschoolers (36-60 months) in childcare centres from Alberta (n = 11) and Ontario (n = 8) in the supporting Healthy physical AcTive CHildcare setting (HATCH) study. In-care ST, light-intensity physical activity (LPA), and moderate- to vigorous-intensity physical activity (MVPA) were accelerometer-derived before and 6 months after the implementation of the new standards. At both time points, cognitive development (working memory, expressive vocabulary), heights, and weights were measured, and BMI Z-scores were calculated. Additionally, the childcare environment was observed using the Environment and Policy Assessment and Observation (EPAO) and Movement Environment Rating Scale (MOVERS) tools. Demographic characteristics were parent-reported and weather variables were derived from Environment Canada data. Mixed models were conducted. RESULTS: In adjusted models (n = 241), change in children's in-care ST (B = -0.07, 95%CI: - 1.43,1.29), LPA (B = 0.08, 95%CI: - 0.89,1.05), and log-transformed MVPA (B = 0.01, 95%CI: - 0.09,0.11) were not significantly different between accreditation and control groups. Age group and the childcare environment were not moderators. Significant increases in BMI Z-score (B = 0.19, 95%CI: 0.03,0.35) and high working memory (OR = 3.24, 95%CI: 1.32,7.97) were observed in the accreditation group and significant increases in expressive vocabulary (B = 3.18, 95%CI: 0.05,6.30) were observed in the control group. CONCLUSIONS: The new accreditation criterion may not significantly change physical activity or ST in childcare settings and therefore may not explain findings for BMI Z-scores and cognitive development. Additional training and resources may be needed.

Problem Technology Use, Academic Performance, and School Connectedness among Adolescents.

BACKGROUND: Little is known about the association between problem technology use in adolescents and school-related outcomes. The purpose of this study was to determine the prevalence of problem technology use and examine its association with academic performance and school connectedness in a sample of students across Ontario, Canada. METHODS: Self-reported data from a sample of 4837 students in grades 9 to 12 (mean age: 15.9 years; 49.5% females) were cross-sectionally analyzed. Ordered logistic regression models were adjusted for important covariates. RESULTS: We found that 35.8% of students used their screen device for at least 5 h a day and about 18.6% had moderate-to-serious symptoms of problem technology use, a prevalence that was higher in females (22.4%) than males (14.9%). Heavy technology use was differentially associated with lower academic performance and lower levels of school connectedness in males and females. Having moderate-to-serious symptoms of problem technology use was associated with lower academic performance among males (AOR = 0.68, 95% CI = 0.53-0.87) and females (AOR = 0.66, 95% CI = 0.52-0.84). It was also associated with less school connectedness in both males (AOR = 0.65, 95% CI = 0.50-0.86) and females (AOR = 0.63, 95% CI = 0.51-0.78). CONCLUSION: Excessive use and problem technology use are highly prevalent among secondary school students, and they are associated with lower academic performance and lower levels of school connectedness.