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 (CVD) in adolescents with and without type 1 diabetes. STUDY DESIGN: Cross-sectional data stem from CARDEA, a study investigating early CVD 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 Montréal, Canada. Outcomes included arterial stiffness by pulse-wave velocity, endothelial function (VTI) 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-h 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 VTI, -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.

Physiological response during exercise is preserved in children exposed to a suboptimal gestational environment.

OBJECTIVE: This study investigated whether exposure to suboptimal gestational factors (SGFs) alters mechanical efficiency (ME) and substrate oxidation during rest and exercise in children as a mechanism contributing to obesity. METHODS: Data from the Quebec Adiposity and Lifestyle Investigation in Youth cohort were used. Children aged 8 to 10 years performed an incremental maximal cycling test with indirect calorimetry. Their ME was measured during submaximal and maximal effort. The substrate oxidation during rest and submaximal effort was also computed. ME and substrate oxidation results between children exposed to each SGF during pregnancy (gestational diabetes mellitus: n = 68; hypertensive disorders: n = 49; maternal smoking: n = 77) and nonexposed children (n = 370) were compared. RESULTS: No difference was observed for ME during submaximal (F[3,540] = 0.46, p = 0.713) and maximal effort (F[3,545] = 0.86, p = 0.463) between exposed and nonexposed children. The percentage contributions of lipids and carbohydrates did not differ during rest (F[3,545] =1.68, p = 0.169) or submaximal exercise (F[3,544] = 0.31, p = 0.534) between exposed and nonexposed children. CONCLUSIONS: Children exposed to investigated SGFs display a similar physiological response regarding ME and substrate oxidation during rest and exercise compared to nonexposed children. Future studies should confirm these novel results and continue investigating other research avenues to explain the higher risk of obesity in this population.

The association between parameters of physical activity and olfactory function-the importance of frequency and moderate intensity.

Introduction: Overall physical activity (PA) has been linked to decreased olfactory dysfunction and could improve olfactory function. Additionally, decreased olfactory function can contribute to reduced overall PA levels, given its association with neurodegenerative disorders. This study aims to examine the relationship between specific PA parameters (duration, frequency, intensity) and olfactory function in adults. Methods: A total of 3,527 participants from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 underwent assessments for weekly PA duration, frequency, and intensity, alongside a smell test (including odors such as chocolate, strawberry, grape, onion, smoke, natural gas, leather, and soap). Correlation analyses and binary logistic regressions using SPSS were used to evaluate associations. Results: The total smell score exhibited small yet significant positive correlations with the duration, frequency, and volume of moderate PA (correlation coefficients ranging between 0.05 and 0.08; all p ≤ 0.05) and frequency of vigorous PA (correlation coefficient of 0.05; p < 0.05). For moderate PA, the duration, frequency, and volume were significantly and positively associated with the ability to correctly detect the smell of grapes while the frequency was significantly and positively associated with the ability to identify smoke and leather odors (odds ratios ranging from 1.01 to 1.07; p < 0.05). For vigorous PA, the frequency of PA was positively associated with the detection of grape smell (odds ratio of 1.05; p < 0.05). Conclusion: Some parameters of an active lifestyle are associated with improved odds of accurately identifying odors by up to 7.4%. Moderate PA duration, frequency, and volume were linked to better olfactory scores, while high-intensity PA had limited associations.

Intensity and Appreciation of Sweet Taste Solutions Are Modulated by High-Intensity Aerobic Exercise in Adolescent Athletic Males.

PURPOSE: Exercise seems to influence taste, but the effect of exercise on specific tastes is still to be elucidated among youths. METHODS: Athlete boys aged 14-16 years were recruited. Participants (n = 19) ages ranged 14.7 (0.7) years, weight 59.6 (7.8) kg, and height of 173.4 (7.9) cm. Distinct taste tests were administered using low and high concentrations of sweet, salty, and bitter solutions before and after a 30-minute aerobic exercise session (70%-90% of estimated maximal heart rate). McNemmar tests, standard paired t tests, Wilcoxon signed-rank tests, and Cohen d effect size tests were used to analyze taste identification, intensity, and appreciation. RESULTS: There were no significant differences in taste identification capacities after exercise. Participants perceived more intense (P = .037) and appreciated better (P = .004) the low-concentration sweet solution after exercise. Taste appreciation was increased for the high-concentration sweet solution (P = .009) after exercise. Effect sizes were moderate (0.516-0.776). Possible effects were noted for the intensity of salty solutions (P = .0501 and .0543). CONCLUSION: Following an exercise session, participants had increased perceived intensity and appreciation of sweet solutions. This adds new insights into how exercise influences taste in youths, a topic less documented compared with adults, suggesting further research into its impact on dietary choices is needed.

Management and outcomes of superficial vein thrombosis: a single-center retrospective study.

Background: Guidelines suggest but cannot recommend the optimal management of superficial vein thrombosis (SVT). Objectives: To identify the prevalence of asymptomatic deep vein thrombosis (DVT) at the time of SVT diagnosis, and to report the treatment and 3-month complications of patients with only SVT more than 3 cm from deep vein junction (or unknown distance). Methods: We performed a single-center retrospective review of patients referred to the Ottawa Hospital thrombosis unit with ultrasound (US)-diagnosed SVT, and followed patients with only SVT for 3 months. Results: Three hundred sixteen patients with SVT were included. Of the 218 patients without DVT symptoms at presentation, 19 (8.7%; 95% CI, 5.7%-13.2%) were found to have asymptomatic concomitant DVT (11 proximal and 8 distal), and 45 (20.6%) had SVT within 3 cm of the saphenofemoral or saphenopopliteal junctions. Among the 192 patients diagnosed with SVT only, we observed 3-month thrombotic complications in 56 (29.2%; 95% CI, 23.2%-36.0%) patients, with a total of 69 events: 11 (5.7%) DVTs, 2 (1.0%) pulmonary embolisms, 37 (19.2%) SVT extensions, and 19 (9.8%) SVT recurrences. Eighty-two percent (9/11) of the 3-month DVT and pulmonary embolism events occurred in patients who initially received conservative management. Therapeutic treatment doses were most effective. Conclusion: At the time of SVT diagnosis, many patients had asymptomatic DVT and SVT near the deep venous system, supporting the systematic use of initial US in patients clinically diagnosed with SVT. The observed differences in 3-month complication rates, according to the treatment provided, highlight the need for large-scale randomized controlled trials to establish optimal management.

HAPI Fit: An Exercise Intervention to Improve Peak Aerobic Capacity in Young Adults Born Very Preterm.

INTRODUCTION: Individuals born preterm have reduced aerobic capacity, which could be related to impaired organ development. Their capacity to improve aerobic capacity with exercise training could therefore be limited, but this remains unknown. We aimed to test an exercise intervention to improve cardiorespiratory fitness in adults born preterm. METHODS: Twenty-one very preterm and 37 full-term individuals aged 18-33 yr took part in a 14-wk supervised exercise intervention of cardiovascular, resistance, and flexibility training (two group and one individual sessions per week). Adherence and compliance to intervention were recorded. Primary outcome was change in peak oxygen consumption (peak V̇O 2 ) measured before and after the intervention. Within- and between-group differences were estimated using nonparametric tests. RESULTS: Of 219 eligible individuals, 58 were enrolled and 14 participants dropped out over the course of the intervention. Among the 44 who completed the intervention, mean adherence was 82% and 66% for group and individual sessions, respectively. Compliance with training requirement varied between 71% and 100%. There was no difference in adherence between the preterm and full-term groups. Because only one preterm male met the adherence criteria, subsequent analyses were done exclusively on females. Both the term and preterm groups achieved higher peak V̇O 2 after the intervention [term = +4.2 (SD 4.3) mL·min -1 ·kg -1 , P < 0.01; preterm = +4.7 (2.9) mL·min -1 ·kg -1 , P < 0.01]. There was no between-group difference in the response to the intervention ( P = 0.729). CONCLUSIONS: Recruitment and adherence to an exercise intervention are challenging. Results could indicate improvements in cardiorespiratory fitness in young women born preterm after current exercise program. Adaptation of this intervention is needed for wider uptake.

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.

Active time at work following the introduction of a standing and a cycling workstation into worker's office space.

Objectives. Active workstations have been proposed to counteract sedentary behavior at work. This study describes office workers' use of and perceptions toward standing and cycling workstations, and assesses whether the two active workstations were sufficient to break sitting time and replace it with 2-4 h of light activity per workday. Methods. This mixed-method study utilized video recording, semi-structured interviews and a questionnaire. The quantitative data covered time spent sitting, standing and on a cycling workstation. The qualitative data were analyzed based on preferences, barriers and facilitators. Results. Participants (n = 15) used active workstations 125.3 (74.5) min/day and spent 79.0 (63.6) min/day using standing versus 46.3 (47.6) min/day using cycling workstations (p = 0.153, d = 0.58). Following the interviews, the standing workstation was preferred over cycling. The ergonomics of the cycling workstation were not optimal and caused discomfort in use. Seven participants broke their sitting time and accumulated 2+ h of light physical activity per workday. Those participants meeting recommendations were older, had a higher body fat percentage and engaged in less physical activity per week. Conclusion. With a preference for standing workstations, our results showed that 47% of workers used standing and cycling workstations to accumulate 2+ h of active time per day.

Effect of odor stimulations on physical activity: A systematic review.

Fewer and fewer people are reaching physical activity recommendations. Therefore, it seems important to make the practice of physical activity more enjoyable to increase the participation rate. Several environmental factors have been studied to see their impact on sports practice, and some studies investigated the effect of odors. This systematic review aims to provide a thorough view of the literature on the effect of different odors on physical activity. The search strategy consisted of using index terms and keywords in MEDLINE, EMBASE, EBM Reviews - Cochrane Central Register of Controlled Trials, CINAHL, SPORTDiscus, and Web of Science search engine. Data from 19 studies that included 458 participants revealed that the odors had different results on strength, cardiovascular, precision, and postural balance tasks depending on the odors' exposition. Among results, an important distinction was made between pleasant and unpleasant odors. Therefore, pleasant odors had better results on physical activity by improving participants' feeling. Even though this review clarified evidence about the effect of odors on physical activity, better methodological consistency is needed across studies such as the odor administration method to produce more meaningful results.

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.

Association between physical activity and taste-The advantage of increased intensity for some but not all individuals.

INTRODUCTION: Taste is a key sensory modulator of energy intake, and while the effects of acute physical activity (PA) on taste have been recently confirmed, its chronic effects remain poorly documented. METHODS: Data were extracted from the NHANES database, including salty and bitter taste tests, moderate PA (MPA) and vigorous PA (VPA) levels, and anthropometric data. Binary logistic regressions were conducted, and odds ratios (ORs) represent the association between physical activity level and successful taste tests. RESULTS: 3,114 participants (51.5% women, mean age 58.5±11.9 years, mean BMI 29.5±7.0 kg/m2) were analyzed. For the tongue tip test, the frequency of VPA was associated with a better score for the bitter and total taste test, while duration of VPA was associated with a better score for the bitter, salty, and total taste test (OR [1.01-1.06], p<0.05). For the whole mouth test, MPA frequency improved the bitter taste score (OR = 1.06, p = 0.01) while VPA frequency and duration were associated with better scores for bitter, salty, and total taste tests (OR [1.01-1.15], p<0.05). These findings were distinctively influenced by weight status and gender, with males and individuals without obesity mainly beneficiating from an active lifestyle. PERSPECTIVES: This study underlines the link between PA, particularly its frequency and intensity, and improved taste preservation. These findings emphasize the potential benefits of regular VPA for optimizing taste perception, although questions remain regarding the advantages for individuals with obesity and the lack of association observed in women who might already have a preserved profile.

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.

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.

Associations of timing of food intake with energy intake, eating behaviour traits and psychosocial factors in adults with overweight and obesity.

Introduction: Whether a late distribution of food intake impacts obesity through increased energy intake remains uncertain and the behavioural characterization of late eating needs to be further investigated. The first objective of this study was to assess the associations between late eating and body mass index (BMI) and total energy intake (TEI), and whether TEI mediates the association between late eating and BMI. The second objective was to assess the associations between late eating and eating behaviour traits or psychosocial factors and whether eating behaviour traits mediate the association between late eating and TEI. Methods: Baseline data from 301 individuals (56% women, age = 38.7 ± 8.5 years; BMI = 33.2 ± 3.4 kg/m2), who participated in four weight loss studies were used in this cross-sectional study. Total energy intake was assessed using a three-day food record from which the percentage of TEI after 17:00 and after 20:00 was calculated. Eating behaviour traits and psychosocial factors were assessed with questionnaires. Pearson correlations and mediation analyses adjusted for age, sex, underreporting of energy intake, sleep duration and bedtime were performed. Results: Percent TEI after 17:00 and after 20:00 were associated with TEI (r = 0.13, p = 0.03 for both), and TEI mediated the association between percent TEI after 17:00 and BMI (ß = 0.01 ± 0.01, 95% CI: 0.001, 0.02). Percent TEI after 17:00 was associated with disinhibition (r = 0.13, p = 0.03) and percent TEI after 20:00 was associated with susceptibility to hunger (r = 0.13, p = 0.03), stress (r = 0.24, p = 0.002) and anxiety (r = 0.28, p = 0.0004). In women, disinhibition mediated the association between percent TEI after 17:00 and TEI (ß = 3.41 ± 1.43, 95% CI: 0.92, 6.47). Susceptibility to hunger mediated the association between percent TEI after 20:00 and TEI (ß = 0.96 ± 0.59, 95% CI: 0.02, 2.34) in men and women. Conclusion: Late eating is associated with TEI and suboptimal eating behaviours which could contribute to explaining the association between timing of food intake and obesity.

Activate Your Health: impact of a real-life programme promoting healthy lifestyle habits in Canadian workers.

The workplace has been suggested as a good setting for the promotion of healthy lifestyles. This article examines the impact of Activate Your Health programme, provided over an average of 1.35 years, on employee health and lifestyle habits (actual and intention to improve). Companies selected one of the programme's four options (number of interventions in parentheses): Control (2), Light (8), Moderate (13) and High (14). Employees (n = 524) completed an online questionnaire at baseline and post-intervention. Mixed-effect models and generalized estimating equations models were used, where appropriate. There was an interaction effect of time by option for the number of employees intending to improve sleep habits (p = 0.030): +11.0% in Light (p = 0.013). No significant interaction effect of time by option was observed for body weight, body mass index, number of health problems or lifestyle habits (actual and intention to improve). When stratified by sex, there was an interaction effect of time by option for the number of women intending to improve sleep habits (p = 0.023): -26.1% in Moderate (p = 0.014). There was an interaction effect of time by option for body weight in men (p = 0.001): -0.58 kg in High (p = 0.031) and +2.58 kg in Control (p = 0.005). Other outcomes of interest were stable or improved post-intervention, regardless of option. The Activate Your Health programme allowed employees to maintain or improve outcomes related to health and lifestyle habits. A package like High may be beneficial for body weight regulation in men.

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.

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.

Body image and health-related behaviors among fitspirit participants.

BACKGROUND: Body image variables such as body size perception (BSP) and body size dissatisfaction (BSD) can influence health-related behaviors. However, few studies have investigated these body image variables in adolescent girls participating in a physical activity intervention. Therefore, the study objectives were to examine the 1) associations between health-related behaviors (physical activity, screen-time, eating habits and sleep duration) and BSP and BSD among girls participating in FitSpirit, a physical activity intervention for girls; and 2) influence of weight control practices on the association between health-related behaviors and BSP and BSD. METHODS: This cross-sectional study assessed a sample of 545 adolescent girls (mean age: 15.0±1.5 years) from 240 schools. Body mass index, health-related behaviors, perceived actual body size and desired body size variables were self-reported and collected via an online questionnaire at the end of the FitSpirit intervention. A negative BSP score [perceived actual body size - calculated BMI z-score] indicates an underestimation of body size. A positive BSD score [perceived actual body size - desired body size] indicates a desire to reduce body size. A multiple linear regression analysis examined the effects of age, zBMI and health behaviors on BSP and BSD. A second multiple linear regression analysis examined the independent associations between BSP and BSD by weight control practice. The linear relationships between BSP and BSD were evaluated with Pearson's correlations. RESULTS: Underestimation and dissatisfaction of body size are more prevalent in participants living with overweight/obesity. Screen-time and sleep duration were independently associated with BSP score (Beta=0.02; P<0.05 and Beta=-0.07; P<0.05, respectively), whereas only screen-time was associated with the BSD score (Beta=0.07; P<0.001). Physical activity was independently associated with the BSP score only in participants trying to control (maintain) their weight (Beta=-0.18; P<0.05). CONCLUSIONS: Body size overestimation and dissatisfaction are associated with health-related behaviors, specifically with more screen-time and less optimal sleeping habits. Physical activity level does not appear to be associated with body image in girls engaged in a physical activity intervention and who want to lose or gain weight. Health promotion interventions could include screen-time and sleep components as they may influence body image.

Healthier Lifestyle for Girls Who Accumulate More Years in the FitSpirit School-Based Intervention.

The main aim was to verify in a group of adolescent girls undergoing a school-based intervention if the number of years of participation in the intervention is related to healthy lifestyle habits, body weight status, and perceived health. Cross-sectional analysis of the FitSpirit data was performed. Body mass index, lifestyle variables, and perceived health were collected through an online questionnaire. Chi-square test, Fisher's test, and ANOVA were performed. Mean age of the 272 girls was 14.7 ± 1.5 years. Higher percentage of girls with 3 or more years of participation met the recommendations for physical activity (PA) and sleep duration (P < .05). Girls who participated ≥3 years showed higher levels of moderate-to-vigorous PA than girls with 1 and 2 years of participation (P < .01). No differences were found between the number of years of participation and body mass index, screen time, fruit/vegetable consumption, or perceived health. A healthier body weight status and following recommendations for healthier habits (PA, screen time, sleep, fruit/vegetable consumption) were related to better perceived health (P < .05). Girls with more years in FitSpirit had healthier lifestyle habits (PA and sleep) compared to those with fewer years. A healthier body weight status and meeting healthy lifestyle recommendations were related to better perceived health.

Is Better Understanding of Management Strategies for Adults With Type 1 Diabetes Associated With a Lower Risk of Developing Hypoglycemia During and After Physical Activity?

BACKGROUND: We aim to determine how knowledge and type 1 diabetes (T1D) management strategies are associated with hypoglycemic risk for physical activity (PA)-induced hypoglycemia among people with T1D (PWT1D). METHODS: One hundred thirty-seven physically active adults with T1D completed diabetes management, PA habits and PA-associated hypoglycemia questionnaire. RESULTS: PA-associated hypoglycemia (during PA, within 1 hour of PA and overnight after PA) was reported by 49% to 61% of respondents, with 18% indicating that they felt inadequately equipped to perform regular PA safely. For during PA, more hypoglycemia was reported by PWT1D with more knowledge of hypoglycemia prevention strategies and those using continuous subcutaneous insulin infusion (CSII) vs multiple injections, those with decreasing basal rate 30 to 60 minutes before PA vs no adjustment before PA, and those taking snacks for unplanned PA vs no snacking. For within 1 hour after PA, more hypoglycemia was reported by PWT1D less knowledgeable about insulin pharmacokinetics and those practicing pre- vs post-dinner PA. For overnight after PA, more hypoglycemia was reported by PWT1D with shorter diabetes duration; CSII users having greater understanding of exercise-induced glucose fluctuations; those reporting reducing nocturnal insulin infusion rates vs no adjustment at night; those engaged in PA for at least 31 minutes; and those engaged in moderate and vigorous PA (vs light PA) as well as regularly performing interval training vs nonregular practice. Glycated hemoglobin and use of continuous glucose monitoring were not associated with any timing of reported PA-associated hypoglycemia. CONCLUSIONS: PA-associated hypoglycemia is common among PWT1D. Greater knowledge of PA and T1D management is not associated with less PA-associated hypoglycemia. Diabetes management confidence could encourage higher tolerance for hypoglycemic risk.