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Purpose: To investigate the association between the neighborhood built environment and trajectories of body mass index (BMI) in youth., Methods: Data were collected in a prospective study of 1293 adolescents in Montreal. Built environment variables were obtained from public databases for road networks, land use, and the Canadian Census. Anthropometric data were collected when participants were ages 12.5, 15 and 17 years. We undertook hierarchical cluster analysis to identify contrasting neighborhood types based on features of the built environment (e.g., vegetation, population density, walkability). Associations between neighborhood type and trajectories of BMI z-score (BMIz) were estimated using multivariable linear mixed regression analyses, stratified by sex., Results: We identified three neighborhood types: Urban, Suburban, and Village. In contrast to the Urban type, the Suburban type was characterized by more vegetation, few services and low population density. Village and Suburban types were similar, but the former had greater land use diversity, population density with more parks and a denser food environment. Among girls, living in Urban types was associated with decreasing BMIz trajectories. Living in Village types was associated with increasing BMIz trajectories. No associations were observed among boys., Conclusions: Neighborhoods characterized by greater opportunities for active living appear to be less obesogenic, particularly among girls., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Purpose: Commonly held hypotheses in practice suggest that compared to single-sport participation, multi-sport participation is associated with higher physical activity (PA) levels and health benefits in the long term. To verify this in the general population, we identified sport participation trajectories during adolescence and examined their associations with PA and health outcomes in young adulthood., Methods: Participants (n = 655) from the Nicotine Dependence in Teens study self-reported sport involvement up to four times per year from age 12 to 17 years. At age 24, PA was assessed using questionnaires and accelerometers, and body composition (i.e., body mass index, waist circumference, skinfold thickness) and blood pressure were measured objectively. We used group-based trajectory modeling to identify sport participation trajectories from age 12 to 17. Associations between trajectories and outcomes in early adulthood were estimated in multivariable linear regression models., Results: We identified four sport participation trajectories during adolescence: non-participants (n = 148, 22%), dropouts (n = 133, 21%), single-sport (n = 248, 37%), and multi-sport participation (n = 126, 20%). Compared to non-participation, multi-sport participation during adolescence was associated with higher self-reported PA in early adulthood (β [95% confidence interval] = 0.26 [0.00-0.52], MET-minutes/week). No association was detected between sport trajectories and accelerometer-measured PA, body composition or blood pressure in early adulthood., Discussion: Our results partially support models suggesting the existence of distinct sport participation trajectories during adolescence and that multi-sport participation is associated with higher self-reported PA levels in adulthood. Our results do not support that sport participation trajectories during adolescence are linked to lower blood pressure or healthier body composition in adulthood., (Copyright © 2022 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: To update a systematic review published in 2012 that identified predictors of cigarette smoking cessation among adolescents., Methods: The PubMed and Web of Science databases were searched for relevant articles published between September 2010 and January 2018, using the following keywords: smoking OR tobacco OR cessation; quit OR stop; longitudinal OR prospective OR cohort. Our search identified 3,399 articles. Inclusion criteria included longitudinal studies (intervention and cohort studies) evaluating cigarette smoking cessation in young people (aged 10-24 years). After screening, in total, 34 articles were included in the review., Results: In total, 63 predictors of smoking cessation among adolescents were identified, with 36 new predictors that were not identified in the previous review: nine sociodemographic factors, 13 psychosocial factors, five behavioral factors, 19 social influences factors, eight smoking related variables, six environmental factors, 2 health related variables, and one genetic factor., Conclusions: To increase the probability of successful smoking cessation, strategies targeting young smokers should consider both individual and environmental predictors of cessation., (Copyright © 2020 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Trajectory analyses differentiate subgroups of smokers based on early patterns of cigarette use, but no study has summarized this literature. We systematically reviewed the literature on adolescent cigarette smoking trajectories to document the number and shapes of trajectories identified, assess if certain study characteristics influence the number or shapes of trajectories identified, summarize factors associated with and outcomes of trajectory group membership, and assess whether the results of trajectory analyses help identify windows of opportunity for intervention. We searched PubMed and EMBASE (1/1/1980 to 1/11/2018) and identified 1695 articles. Forty-three articles with data from 37 unique datasets were retained. Each trajectory was categorized into one of three groups (i.e., low-stable, increasing, other). Number of trajectories ranged from 2 to 6 (mode = 4); 44-76% of participants were low-stable cigarette consumers, 11-21% increased consumption, and 3-11% were categorized as "other." Number of data points, smoking indicator used, and time axis influenced the number of trajectories identified. Only two articles depicted the natural course of smoking since onset. Factors associated with trajectory membership included age, sex/gender, race/ethnicity, parental education, behavior problems, depression, academic performance, baseline cigarette use, parental and friends smoking, alcohol use, and cannabis use. Outcomes included illicit drug and alcohol use. Beyond parsimoniously describing cigarette smoking patterns, it is not clear whether trajectory analyses offer increased insight into the natural course, determinants or outcomes of cigarette smoking in ways that inform the development of intervention., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: In young people, alcohol consumption and depressive symptoms are related, but the temporal ordering of the relationship is an open question. Previous studies have not disaggregated influences of interindividual and intraindividual components affecting the relationship. We investigated whether a reciprocal relationship between frequency of alcohol use and depressive symptoms exists in the general population of adolescents after removing interindividual influences., Methods: A total of 1,293 Canadian adolescents provided data on depressive symptoms and frequency of alcohol use every 3 months from grade 7 to 11 (1999-2005) for a total of 20 cycles. We used latent curve models with structured residuals, which disaggregate interindividual and intraindividual components to assess the directionality of the relationship., Results: Both drinking frequency and depressive symptoms increased linearly and quadratically over time, with significant interindividual variation around the origin and rate of change. Intercepts and slopes for drinking frequency and depressive symptoms differed by sex and age. After controlling for sex, age, maternal education, sensation seeking, impulsivity and clustering by school, a significant positive association was observed between depressive symptoms and drinking frequency 3 months later (.032 [.004, .060]; p = .024), but no association was observed between drinking frequency and subsequent depressive symptoms (.011 [-.006 to .029]; p = .193)., Conclusions: Our data provide longitudinal evidence that changes in depressive symptoms exceeding one's "normal" level predict increases in drinking frequency. This suggests that teaching youth to recognize and cope with mood changes would be worthwhile., (Copyright © 2019 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Nicotine dependence (ND) symptoms can occur soon after first puff, so that stopping smoking becomes difficult well before 100 cigarettes lifetime is attained. Yet some surveillance systems do not monitor ND symptoms and 100-cigarettes lifetime is used in at least one surveillance system to define current smokers. To assess whether these features limit interpretation of grade-specific data in surveillance, we described smoking and ND symptoms across grade in incident vs. prevalent smokers, and in smokers according to 100-cigarettes lifetime., Methods: Data were available in an investigation of 1294 grade 7 students from 10 Montreal-area high schools followed every 3 months from grade 7 to 11. Analyses described cigarette consumption, 100-cigarette lifetime consumption, cravings, withdrawal symptoms, mFTQ nicotine dependence and ICD-10 tobacco dependence by grade among past 3-month smokers., Results: Despite low cigarette consumption, 21-30% of grade 7 smokers reported ND symptoms. This increased to 27-44% in grade 8 and remained stable thereafter despite increased cigarette consumption. In grade 7, 10% of all smokers had not attained the 100-cigarette milestone but were already dependent. In grade 8, 9, 10 and 11, these proportions were 12%, 8%, 6% and 6%, respectively., Conclusions: ND symptoms should be monitored in youth surveillance systems since they tell a different "story" than cigarettes and their appearance may represent a critical "point-of-no-return." Interventions for incident smokers are needed across grades to stop smoking before ND manifests. Without a shift in focus toward incident rather than established smokers, many children who try cigarettes will become addicted., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Purpose: Sport participation promotes mental health and prevents mental illness. However, the association between specific sport profiles and mental health has not been examined. We investigate the longitudinal association between number of years with a recreational or performance sport profile and mental health during adolescence and whether these associations differ by sex., Methods: Participants (n = 318, 58.2% female) reported participation in sport every 4 months over 5 years, from ages 10-11 to 14-15 years. Each year, they were categorized as recreational or performance sport participants or as nonparticipants. Mental health was assessed at age 15-16 years. Multivariate linear regression was used to model the association between number of years (0-5) with a recreational and performance sport profile and mental health, controlling for sex, age, income, and age at puberty., Results: A recreational sport profile for ≥2 years was associated with better mental health compared with 0 years of recreational sport participation; the strongest association was observed for a recreational sport profile of 4-5 years (βˆ [95% confidence interval]: 10.29 [2.60, 17.98]). A performance sport profile for ≥1 year was associated with better mental health in late adolescence compared with 0 years of performance sport participation; the strongest association was observed for a performance sport profile of 4-5 years (βˆ [95% confidence interval]: 19.48 [9.50, 29.46]). No differences by sex were observed., Conclusion: Both recreational and performance sport profiles in childhood and early adolescence are positively associated with mental health in late adolescence. To promote mental health, strategies to encourage youth to engage and remain involved in sport are warranted., (Copyright © 2019 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: Little is known about age-related differences in risk factors for cigarette smoking initiation. We identified predictors of initiation in early, middle, and late adolescence from among sociodemographic factors, indicators of smoking in the social environment, psychological characteristics, lifestyle indicators, and perceived need for cigarettes., Methods: Data were drawn from a longitudinal study of 1,801 children recruited at age 10-11 years from 29 elementary schools in Montreal, Canada. Multivariable logistic regression within a generalized estimating equations framework was used to identify predictors among never smokers across three 2-year windows: age 11-13 years (n = 1,221); age 13-15 years (n = 737); and age 15-17 years (n = 690)., Results: Among the 18 risk factors investigated, two differed across age. Friends' smoking, a strong risk factor in early adolescence (odds ratio [95% confidence interval] = 5.78 [3.90-8.58]), lost potency in late adolescence (1.83 [1.31-2.57]). Depressive symptoms, a risk factor in early and middle adolescence (1.60 [1.26-2.02] and 1.92 [1.45-2.54], respectively), were inversely associated in late adolescence (.76 [.58-1.00]). Sex, TV viewing, and weight-related goals were not associated with initiation at any age. All other factors were significant in two or three age groups., Conclusions: Most risk factors for smoking initiation were stable across age. Tobacco control interventions may be robust for risk factors across age groups and may not need adjustment. At all ages, interventions should focus on eliminating smoking in the social environment and on reducing the availability of tobacco products., (Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: Heavy episodic (i.e., "binge") drinking (i.e., ≥five drinks/occasion) is highly prevalent among young adults; those who binge do so four times per month on average, consuming nine drinks on average on each occasion. Although it is well established that chronic heavy drinking (≥two alcoholic beverages per day) increases the risk of hypertension, the relationship between binge drinking and blood pressure is not well described. Our aim was to describe the relationship between frequency of binge drinking, both current (at age 24 years) and past (at age 20 years), and systolic blood pressure (SBP) at age 24 years., Methods: Participants (n = 756) from the longitudinal Nicotine Dependence in Teens study reported alcohol consumption at ages 20 and 24 years and had SBP measured at age 24 years. We examined the association between binge drinking and SBP using multiple linear regression, controlling for sex, race/ethnicity, education, monthly drinking in high school, cigarette smoking, and body mass index., Results: Compared to nonbinge drinkers, SBP at age 24 years was 2.61 [.41, 4.82] mm Hg higher among current monthly bingers and 4.03 [1.35, 6.70] mm Hg higher among current weekly bingers. SBP at age 24 years was 2.90 [.54, 5.25] mm Hg higher among monthly bingers at age 20 years and 3.64 [.93, 6.35] mm Hg higher among weekly bingers at age 20 years, compared to nonbinge drinkers., Conclusions: Frequent binge drinking at ages 20 and 24 years is associated with higher SBP at age 24 years and may be implicated in the development of hypertension., (Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: To study the effect of maternal psychiatric disorders (depression, anxiety disorder, bipolar disease, schizophrenia, unspecified psychiatric disorder, and comorbid conditions) and odds of preterm birth., Methods: The Consortium on Safe Labor (2002-2008), an observational cohort with 12 centers from across the United States included 223,394 singleton pregnancies with clinical data obtained from electronic medical records and maternal diagnoses of psychiatric disorders from maternal discharge summaries. Length of gestation was based on the best clinical estimate and categorized as birth less than 39, less than 37, less than 34, and less than 28 weeks' gestation. The adjusted odds ratios (ORs) with 95% confidence intervals of birth were estimated by logistic regression with generalized estimating equations., Results: Any maternal psychiatric disorder was associated with odds of birth less than 39 weeks' gestation (odds ratio [OR] = 1.32, 95% confidence interval = 1.28-1.37), less than 37 weeks' gestation (OR = 1.45, 1.38-1.52), less than 34 weeks' gestation (OR = 1.47, 1.35-1.59), and less than 28 weeks' gestation (OR = 1.57, 1.36-1.82). Specifically, odds of birth less than 37 weeks' gestation were associated with maternal depression (OR = 1.31, 1.23-1.40), anxiety disorder (OR = 1.68, 1.41-2.01), depression with anxiety disorder (OR = 2.31, 1.93-2.78), bipolar disease (OR = 1.54, 1.22-1.94), bipolar disease with depression and/or anxiety disorder (OR = 1.70, 1.30-2.22), and unspecified psychiatric disorder (OR = 1.52, 1.41-1.64)., Conclusions: Maternal psychiatric disorders, especially comorbid psychiatric conditions, were associated with increased likelihood of preterm birth., (Published by Elsevier Inc.)

Background: Smoking is influenced by genetic factors including variation in CYP2A6 and CYP2B6, which encode nicotine-metabolizing enzymes. In early adolescence, CYP2A6 slow nicotine metabolism was associated with higher dependence acquisition, but reduced cigarette consumption. Here we extend this work by examining associations of CYP2A6 and CYP2B6 with tobacco dependence acquisition in a larger sample of smokers followed throughout adolescence., Methods: White participants from the Nicotine Dependence in Teens cohort that had ever inhaled (n=421) were followed frequently from age 12-18 years. Cox's proportional hazards models compared the risk of ICD-10 tobacco dependence acquisition (score 3+) for CYP2A6 and CYP2B6 metabolism groups. Early smoking experiences, as well as amount smoked at end of follow-up, was also computed. At age 24 (N=162), we assessed concordance between self-reported cigarette consumption and salivary cotinine., Results: In those who initiated inhalation during follow-up, CYP2A6 slow (vs. normal) metabolizers were at greater risk of dependence (hazards ratio (HR)=2.3; 95% CI=1.1, 4.8); CYP2B6 slow (vs. normal) metabolizers had non-significantly greater risk (HR=1.5; 95% CI=0.8, 2.6). Variation in CYP2A6 or CYP2B6 was not significantly associated with early smoking symptoms or cigarette consumption at end of follow-up. At age 24, neither gene was significantly associated with dependence status. Self-reported consumption was associated with salivary cotinine, a biomarker of tobacco exposure, acquired at age 24 (B=0.37; P<0.001)., Conclusions: Our findings extend previous work indicating that slow nicotine metabolism mediated by CYP2A6, and perhaps CYP2B6, increases risk for tobacco dependence throughout adolescence., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Introduction: The few population-based studies that investigate the association between cannabis use and adiposity are inconclusive possibly because nicotine moderates the effect of cannabis on adiposity. The objective was to test the hypotheses that the association between cannabis use and adiposity in young men and women is modified by cigarette smoking., Methods: Data were drawn from the Nicotine Dependence in Teens (NDIT) study, a 13-year prospective cohort investigation of the natural course of nicotine dependence. A total of 271 males and 319 females aged 12-13years at cohort inception provided data on past-year cannabis use and number of cigarettes smoked per day in the past three months, at age 20years. Outcomes included change in body mass index (BMI) and in waist circumference (WC) from ages 17 to 24years. The hypothesis was tested in multiple linear regression models that included interaction terms for cannabis use and cigarette smoking and controlled for physical activity, sedentary behavior, alcohol use, and level of the outcome at baseline., Results: The association between cannabis use and change in adiposity was U-shaped in male non-smokers and in females, and an inverted U-shape in male smokers. In males, the interaction between cannabis use and cigarette smoking was significant in both the models for change in BMI (p=0.004; n=271) and change in WC (p=0.04; n=250). In females, the interaction between cannabis use and cigarette smoking was not significant., Conclusion: Smoking cigarettes appears to modify the association between cannabis use and adiposity in young men., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: This longitudinal study examined the association between participation in school sport during adolescence and mental health in early adulthood., Methods: Adolescents (n = 853) reported participation in school sport in each grade throughout the 5 years of secondary school. In early adulthood, participants reported depressive symptoms, level of stress, and self-rated mental health., Results: Involvement in school sport during adolescence was a statistically significant predictor of lower depression symptoms, lower perceived stress, and higher self-rated mental health in young adulthood., Conclusions: School sport participation may protect against poor mental health in early adulthood. Policies to increase school sport participation may be warranted as part of public health strategies to promote mental health., (Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Background: The level of physical dependence is a measure of addiction that correlates highly with addiction-associated changes in brain structure. We sought to determine whether age at first inhalation and initial reactions to inhaling nicotine are related to level of physical dependence in early adulthood., Methods: Young adults (n=312; mean age=24 years; 51% female) from the Nicotine Dependence in Teens study who had smoked at least once in the preceding three months completed self-report questionnaires in 2011-12. We assessed level of physical dependence with three validated self-report items assessing 'wanting,' 'craving' and 'needing' triggered by nicotine deprivation. Survey items assessed smoking behavior, including age at first inhalation, and recalled first reactions to inhaling nicotine., Results: After adjusting for covariates, experiencing relaxation, heart racing/pounding, rush or "buzz" (OR=1.45; 95% CI: 1.08, 1.94) and dizziness (OR=1.58; 95% CI: 1.15, 2.18) at first nicotine inhalation were associated with an increased odds of being at a higher level of physical dependence in young adulthood; the association for experiencing relaxation (OR=1.78; 95% CI: 1.20, 2.64) and heart racing/pounding (OR=1.51; 95% CI: 1.00, 2.28) persisted after additionally controlling for all other first reactions. Neither age at first inhalation nor unpleasant first reactions predicted level of physical dependence., Conclusions: In accordance with prior research, our findings suggest that smokers who are particularly sensitive to the pleasant, "buzz-related" and generally arousing effects of nicotine may be more likely to attain higher levels of physical dependence., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Little is known about longitudinal associations between added sugar consumption (solid and liquid sources) and glucose-insulin homeostasis among youth. Caucasian children (8-10 y) with at least one obese biological parent were recruited in the QUébec Adipose and Lifestyle InvesTigation in Youth (QUALITY) cohort (n = 630) and followed-up 2 y later (n = 564). Added sugars were assessed by 3 24-h dietary recalls at baseline. Two-year changes were examined in multivariate linear regression models, adjusting for baseline level, age, sex, Tanner stage, energy intake, fat mass (dual-energy X-ray absorptiometry), and physical activity (7 d accelerometer). Added sugar intake in either liquid or solid sources was not related to changes in adiposity measures (fat mass, body mass index, or waist circumference). However, a higher consumption (10 g/d) of added sugars from liquid sources was associated with 0.04 mmol/L higher fasting glucose, 2.3 pmol/L higher fasting insulin, 0.1 unit higher homeostasis model assessment of insulin resistance (HOMA-IR), and 0.4 unit lower Matsuda-insulin sensitivity index (Matsuda-ISI) in all participants (P < 0.01). No associations were observed with consumption of added sugars from solid sources. Overweight/obese children at baseline had greater increases in adiposity indicators, fasting insulin, and HOMA-IR and decreases in Matsuda-ISI during those 2 y than normal-weight children. Consumption of added sugars from liquid or solid sources was not associated with changes in adiposity, but liquid added sugars were a risk factor for the development of impaired glucose homeostasis and insulin resistance over 2 y among youth at risk of obesity.

Purpose: To describe the incidence and identify predictors of smoking initiation in young adults., Methods: Data were collected in self-report questionnaires in 22 cycles over 13 years in a prospective cohort investigation of 1,293 students recruited in 1999-2000 from all grade 7 classes in a convenience sample of 10 high schools in Montreal, Canada. Participants were 12.7 years of age on average at cohort inception and 24.0 years of age in cycle 22. Independent predictors of smoking initiation in young adulthood (post-high school) were identified in multivariable logistic regression analysis using generalized estimating equations., Results: Of 1,293 participants, 75% initiated smoking by cycle 22. Of these, 44%, 43%, and 14% initiated before high school, during high school, and in the 6 years after high school, respectively. The incidence density rate of initiation was .33, .13, .14, .11, and .12 initiation events per person-year in grade 7, 8, 9, 10, and 11, respectively, and .05 post-high school. Independent predictors of smoking initiation in young adults included alcohol use, higher impulsivity, and poor academic performance., Conclusions: A total of 14% of smokers who initiated smoking before age 24 years did so after high school. The predictors of initiation in young adults may provide direction for relevant preventive interventions., (Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: Findings from prospective studies on associations between physical activity and adiposity among youth are inconsistent. Our aim was to describe physical activity trajectories during secondary school and examine the association with change in adiposity in youth., Methods: Physical activity was measured in 20 survey cycles from 1999 to 2005; anthropometrics were measured in survey cycles 1, 12, and 19. Individual growth curves modeling moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) were estimated. Estimates of initial level and rate of decline in MVPA and VPA bouts per week were included as potential predictors of body fat% and body mass index using age- and sex-specific linear regression., Results: Complete data were available for 840 and 760 adolescents aged 12-13 years at baseline, followed from survey cycles 1-12 and 12-19, respectively. Among girls, yearly declines of one MVPA and one VPA bout per week during earlier adolescence were associated with increases of 0.19 (95% confidence interval [CI], 0.02-0.36) and 0.47 (95% CI, 0.015-0.92) units of body fat%, respectively. In boys, a yearly decline of one MVPA bout per week was associated with an increase of 0.38 (95% CI, 0.05-0.70) units of body fat% during later adolescence., Conclusions: Obesity prevention programs should include strategies to prevent declines in physical activity., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Recent cross-sectional studies suggest some adolescents who have never smoked cigarettes experience nicotine dependence (ND) symptoms and that exposure to second-hand smoke, social exposure to smoking, and alcohol use are plausible correlates. The aim of this study was to replicate and extend these findings by investigating possible predictors of ND symptoms longitudinally., Method: Participants included 847 secondary school students who had never smoked cigarettes enrolled in the Nicotine Dependence in Teens Study. Adolescents completed self-report questionnaires measuring smoking status, ND symptoms, and risk factors for ND in smokers (i.e., socio-demographic indicators, social exposure to smoking, psychosocial indicators, and substance use) in 20 survey cycles from 7 to 11th grade. Generalized estimating equations, which account for repeated measures within individuals, were used to test the predictors of ND symptoms., Results: Consistent with previous research, 7.8% of never-smokers across all cycles endorsed at least one ND symptom. Younger age (p ≤ .001), country of birth (p ≤ .05), peer smoking (p ≤ .001), teacher smoking (p ≤ .05), depression (p ≤ .05), stress (p ≤ .001), lower self-esteem (p ≤ .05), impulsivity (p ≤ .05), and alcohol use (p ≤ .001) predicted greater ND symptoms in multivariable modeling., Conclusions: Replicating previous cross-sectional findings, peer smoking and alcohol use predicted ND symptoms among never-smoking adolescents. Extending these findings, previous predictors only observed among ever-smokers, including socio-demographic and psychosocial indicators, also predicted ND symptoms. This longitudinal investigation demonstrated the temporal relation of the predictors preceding ND symptoms. Future research should consider longer prospective studies with younger children to capture early onset of ND symptoms and with longer follow-up to detect eventual smoking uptake., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Purpose: The objectives of this study were to assess (1) the longitudinal associations of past moderate-to-vigorous physical activity (MVPA) and involvement in team sports during secondary school with depressive symptoms in early adulthood, and (2) the cross-sectional associations of current MVPA and involvement in team sports with depressive symptoms during young adulthood., Methods: Data were drawn from the Nicotine Dependence in Teens study, which is an ongoing prospective cohort study of 1293 adolescents aged 12-13 years at baseline (52% female). Data analyses involved latent growth curve modeling and multiple hierarchical linear regression models., Results: Current MVPA (β = -0.12), but not past MVPA, participation was significantly negatively related to depressive symptoms during young adulthood (P < .05). Both current and past involvement in team sports were significantly negatively related to depressive symptoms (β ≥ -0.09; P < .05); however, these associations were no longer significant (P = .08) when covariates were controlled for., Conclusions: Findings provide insight about the unique associations between the timing and type of physical activity and depressive symptoms, suggesting that physical activity within team sport contexts should be encouraged so that young adults may experience less depressive symptoms., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: To assess whether a child's age relative to the median age of classmates in the same grade is associated with the onset of gambling., Methods: Grade 7 students (n = 647) from 10 Montreal secondary schools were followed for 8 years. Relative age was expressed as years above or below the school-specific grade 7 median age. Hazard ratios and 95% confidence intervals (CI) were estimated for the association between relative age and age of gambling onset, with adjustment for sex, ethnicity, parent education, and impulsivity., Results: A greater proportion of students in the youngest quartile gambled compared with the oldest (85.8% vs 74.7%). Hazards of gambling onset for students younger than the median age were elevated after age 10.5 years, but hazards were protective beforehand. At age 17 years, for example, the hazard for gambling onset was 61% greater (95% CI 1.4-1.9) for youth who were 1 year younger, but at age 8 years the hazard was 23% lower (95% CI 0.7-0.9)., Conclusions: Younger relative age may be a risk factor for gambling onset in older youth., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Objectives: The primary objective of this report was to describe the infrastructures and processes of selected European and North American pre-hospital fibrinolysis (PHL) programs. A secondary objective is to report the outcome data of the PHL programs surveyed., Background: Despite its benefit in reducing mortality in patients with ST-segment elevation myocardial infarction, PHL remained underused in North America. Examination of existing programs may provide insights to help address barriers to the implementation of PHL., Methods: The leading investigators of PHL research projects/national registries were invited to respond to a survey on the organization and outcomes of their affiliated PHL programs., Results: PHL was successfully deployed in a wide range of geographic territories (Europe: France, Sweden, Vienna, England, and Wales; North America: Houston, Edmonton, and Nova Scotia) and was delivered by healthcare professionals of varying expertise. In-hospital major adverse outcomes were rare with mortality of 3% to 6%, reinfarction of 2% to 5%, and stroke of <2%., Conclusions: Combining formal protocols for PHL for some patients with direct transportation of others to a percutaneous coronary intervention hospital for primary percutaneous coronary intervention would allow for tailored reperfusion therapy for patients with ST-segment elevation myocardial infarction. Insights from a variety of international settings may promote widespread use of PHL and increase timely coronary reperfusion worldwide., (Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: We sought to determine if the rate of increase in body mass index (BMI) differs between first generation immigrant children (child and both parents born outside Canada); second generation immigrant children (child born in Canada with at least one parent born outside Canada); and native-born children (child and both parents born in Canada), and if the rate of increase varies across ethnic groups., Methods: Data were available from the evaluation of a 5-year heart health promotion program targeted to elementary school children from 24 schools in multi-ethnic, disadvantaged, inner-city neighborhoods in Montreal, Canada. Participants were 6392 children aged 9-12 years born in and outside of Canada. Height and weight were measured annually according to a standardized protocol. BMI increases with age were examined using individual growth models stratified by immigrant status grouping (first generation immigrant, second generation immigrant, native-born)., Results: On average, BMI increased by 0.59, 0.73, and 0.82 kg/m2 with each year of age among first generation immigrant, second generation immigrant, and native-born children, respectively. These differences held across four family origin grouping (Europe, Asia, Central/South America, and Other)., Conclusion: The protective effect of immigrant status on BMI increases with age dissipated in second generation immigrant children, whose rate of increase was similar to that of native-born children. Because immigrants constitute the fastest growing segment of the Canadian population, it is important to understand the causes of the higher BMI increases with successive generations., (Copyright © 2011 Elsevier Inc. All rights reserved.)

In addition to its recognized role in bone health, recent studies point to vitamin D functions in other tissues, including the pancreas. We tested the association between the vitamin D status and glucose and lipid homeostasis in a school-based, cross-sectional survey of a representative sample of youth. We measured fasting plasma insulin, glucose, total cholesterol (TC), triglycerides (TG), HDL cholesterol (HDL-C) apolipoproteins (apo) A1 and B, and 25-hydroxyvitamin D [25(OH)D] concentrations in 878 boys and 867 girls. The 25(OH)D concentrations (mean +/- SD) were 45.9 +/- 12.2 nmol/L in boys and 45.9 +/- 13.0 nmol/L in girls. More than 93% of youth had suboptimal (<75 nmol/L) vitamin D concentrations. There was a slightly lower glycemia, -0.5% (P = 0.015) and -0.4% (P = 0.025), and homeostasis model assessment of insulin resistance, -2.8% (P = 0.043) and -2.3% (P = 0.050), for each 10-nmol/L increase in plasma 25(OH)D in boys and girls, respectively. In contrast, in girls only there were modest increases in plasma TC (1.1%; P = 0.017), TG (2.9%; P = 0.004), apoA1 (1.2%; P < 0.001), and apoB (1.5%; P = 0.023). We observed no association between the presence of at least 2 cardiometabolic risk factors (borderline/unfavorable fasting concentrations of apoB, HDL-C, TG, insulin, and glucose) and 25(OH)D concentrations in either boys or girls. Although the observed associations between 25(OH)D concentrations and fasting glucose, and variables of lipid metabolism are modest, they may have a potential long-term impact on cardiovascular risk.

The "healthy immigrant effect" may apply to lifestyle-related behaviors in immigrant children. In a cross-sectional study of 1,959 children aged 9-12 years, the number of years lived in Canada was related to an increased risk of smoking among immigrant children. Interventions may be needed for immigrant children to prevent the adoption of unhealthy behaviors prevalent in their new host environments.

Introduction: Several meta-analyses have examined the efficacy of smoking cessation therapies in the general population. However, little is known about the efficacy of these therapies in cardiac patients. Therefore, a meta-analysis of randomized controlled trials (RCTs) was performed to determine the efficacy of behavioural therapy and pharmacotherapy for smoking cessation in cardiac patients., Methods: The medical literature was systematically reviewed to identify smoking cessation RCTs in cardiac patients. Only RCTs that reported smoking abstinence at six or 12 months were included. Smoking abstinence was examined based on the 'most rigorous criterion', defined as the most conservative outcome reported in any given RCT., Results: Eleven behavioural therapy RCTs that enrolled 2105 patients and four pharmacotherapy RCTs that enrolled 1542 patients were identified. RCTs differed in the type of behavioural therapy administered as well as the total length and duration of the intervention. RCTs differed in the type of pharmacotherapy administered (one nicotine patch RCT, one nicotine gum RCT and two bupropion RCTs). Behavioural therapy was associated with a significantly higher proportion of smoking abstinence than usual care (OR 1.97 [95% CI 1.37 to 2.85]). Pharmacotherapies were more efficacious than placebo (pooled OR 1.72 [95% CI 1.15 to 2.57])., Conclusions: Both behavioural therapy and pharmacotherapy are more efficacious than usual care for smoking cessation in cardiac patients. The present meta-analysis highlights the need for head-to-head RCTs to identify which smoking cessation therapy is preferred in cardiac patients as well as RCTs examining the efficacy of combined behavioural and pharmacotherapies.

Purpose: Little is known about how seasonal variation in physical activity relates to declining physical activity in adolescence. We quantified how each of daily weather conditions and season affect physical activity during adolescence., Methods: We followed 1293 students, initially aged 12 to 13 years over 5 years. Participants completed a 7-day physical activity recall checklist every 3 months. Data on daily weather conditions were obtained from Environment Canada. The association between the number of physical activity sessions per day, and each of season, and daily weather conditions was assessed in Poisson regressions., Results: Adjusting for age, sex, and month, the average number of physical activity sessions per day was 2% to 4% lower for every 10 mm of rainfall and 1% to 2% higher for every 10 degrees C increase in temperature. Although every 10 cm of snow accumulation was associated with 5% higher activity rates, days with snowfall had lower physical activity. Physical activity was lower during winter and increased during warmer months. However, the warm-month increases did not compensate for winter decreases so that activity decreased by 7% yearly., Conclusions: Declines in physical activity during adolescence may be partly explained by declines during winter. Increasing opportunities for physical activity during poor weather, in particular during winter, may mitigate declines in physical activity during adolescence.

Background: There are few data on the prevalence of cardiometabolic risk factors in population-based samples of overweight and obese youth., Objectives: To compare the prevalence of individual and multiple cardiometabolic risk factors across body mass index (BMI) categories in a population-based sample of youth., Methods: In 1999, a school-based survey of a provincially representative sample of youth nine, 13 and 16 years of age was conducted in Quebec (1778 boys, 1835 girls). Overweight was defined as BMI in the 85th percentile or higher and lower than the 95th percentile of the Centers for Disease Control and Prevention 2000 growth charts, and obesity was defined as BMI in the 95th percentile or higher. Levels of total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, high-density lipoprotein cholesterol, triglycerides, insulin, glucose, C-reactive protein and systolic blood pressure were categorized as desirable, borderline or unfavourable., Results: The proportions of overweight and obese participants were 14% and 10% in boys, and 14% and 7% in girls, respectively. With the exception of total cholesterol and low-density lipoprotein cholesterol in girls, and glucose in both sexes, the prevalence of all investigated risk factors (borderline or unfavourable) was significantly higher among overweight and obese participants. Almost one-third of obese participants had unfavourable levels of at least two of seven risk factors (apolipoprotein B, high-density lipoprotein cholesterol, triglycerides, insulin, glucose, C-reactive protein and systolic blood pressure) compared with 3% of normal weight participants (adjusted OR 15 and 18 in boys and girls, respectively). Thirty-four per cent of obese youth did not have unfavourable levels of any risk factor., Conclusion: There is marked heterogeneity in the association between excess weight and cardiometabolic risk factors. Nonetheless, the present study highlights a high prevalence of multiple risk factors in a population-based sample of overweight and obese youth.

Purpose: To study the effect of cigarette use on height and adiposity in adolescents., Methods: Data on cigarette use were collected every 3 months for 5 years from adolescents initially 12-13 years of age. Height, weight, and triceps skinfold thickness were measured in survey cycles 1, 12, and 19. Multivariate linear regression models were fitted to estimate the association between cigarette use and the anthropometric measures in a dataset that pooled data over two time periods, from survey cycles 1-12 and from survey cycles 12-19., Results: Data were available for 451 boys and 478 girls. Seven percent of boys and 14% of girls smoked > or =30 cigarettes per month on average during the first time period; 9% of boys and 18% of girls smoked > or =30 cigarettes per month on average during the second time period. In boys, a 100-cigarette per month increment in cigarette use over the preceding 2.5 years was independently associated with lower body mass index (-0.4 kg/m(2)) and shorter height (-0.7 cm). In girls, cigarette use was not associated with height or adiposity., Conclusions: While there was no relation in girls, cigarette use appears to decrease body mass index and height in boys. Young girls may be less likely to take up cigarette smoking if tobacco control messages emphasize that cigarette use may not be associated with reduced weight in adolescent females.

Objective: To describe the delivery of smoking preventive counseling to preadolescent, adolescent, and young adult patients in an Arab population, and to examine counseling behavior according to physician demographic characteristics and perceived barriers to counseling., Methods: A cross-sectional mail survey was carried out among general practitioners (GPs) in private practice in the Emirates of Sharjah, Dubai and Abu Dhabi., Results: Of 391 eligible GPs, 218 (56%) completed the questionnaire. Overall 29, 50 and 65% of GPs offered preventive advice to preadolescents (9-12 years), adolescents (13-19 years) and young adults (20-24 years), respectively. Lack of patient educational materials was cited by 71.8% of GPs as a very important barrier to offering smoking prevention counseling, followed by lack of community resources (66.5%) and lack of time (62.2%). Older age, male gender, and having knowledge of the stages of change were positively associated with offering preventive advice., Conclusion: Physician self-reports of their smoking prevention counseling practices suggest there is opportunity for improvement. More training and support is needed to improve and encourage physician adherence to current smoking prevention counseling guidelines., Practice Implication: More research is needed to determine the most effective method to improve delivery of preventive care by GPs, and to communicate appropriate preventive or cessation messages.

Purpose: To describe longitudinal trajectories of smoking intensity in adolescent novice smokers and to identify predictors of trajectory class membership., Methods: Cigarette consumption among 369 novice smokers (mean age 13 years) was measured over a mean 24 months of follow-up after smoking onset. Classes of smoking intensity trajectories were identified using latent class growth modeling. Predictors of trajectory class membership were identified in polytomous logistic regression., Results: There was considerable between-subject heterogeneity in individual trajectories over time. Four classes of smoking intensity trajectories were identified: low-intensity, non-progressing smokers (72.4% of subjects), and slow, moderate, and rapid escalators (11.1%, 10.8%, and 5.7% of subjects, respectively). Gender, poor academic performance, and having more than half of friends who smoke at smoking onset independently predicted development of trajectory pattern. Escalating trajectory patterns were associated with earlier development of nicotine dependence and tolerance., Conclusions: Cigarette consumption will not escalate rapidly among three-quarters of adolescent novice smokers. Novice smokers who do escalate rapidly should be targeted for early tobacco control intervention to prevent development of nicotine dependence and sustained smoking.

Growing evidence suggests an association between lipid abnormalities and fatty acid binding protein (FABP) and microsomal triglyceride transfer protein (MTP) gene variants. Our objectives were to determine whether Ala54Thr FABP2 and G-493T MTP polymorphisms are associated with increased risks of insulin resistance syndrome (IRS) in youth and/or modify the expression of accompanying dyslipidemia. Our study of 1,742 French-Canadians aged 9, 13, and 16 years did not provide evidence of a potential predisposition to IRS related to either FABP2 or MTP genotypes. However, we observed a heterogeneity of the FABP2 effect by IRS status on total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), and apolipoprotein B (apoB) concentrations (P for interaction=0.045, 0.018, and 0.017, respectively). Among the metabolic components of IRS, only triglyceride (TG) displayed an interaction with FABP2 polymorphism: compared with Thr/Ala and Ala/Ala, the Thr/Thr genotype was associated with a steeper increase in TC, LDL-C, and apoB parallel to TG concentrations (P <0.001). IRS did not modify the associations between the MTP polymorphism and any of the biochemical parameters. Our study suggests that the effects of FABP2 allelic variations on lipid traits are context dependent, indicating that this variant may play an important role in cardiovascular pathogenesis in the presence of IRS or hypertriglyceridemia.

Background: Although atherosclerosis begins in childhood, there are no recent Canadian data on cardiovascular risk factors in provincially or nationally representative samples of youth., Objective: To describe the design and methods of the 1999 Québec Child and Adolescent Health and Social Survey, which assessed the prevalence and distribution of risk factors in a representative sample of Québec youth., Methods: School-based, multistage, cluster sampling survey of youth aged nine, 13 and 16 years. Measures included height, weight, subscapular and tricipital skinfolds, blood pressure (measured with the Dinamap), a fasting blood draw for assessment of lipoproteins and glucose, an age-adapted youth questionnaire on lifestyles and a parent questionnaire., Results: One thousand two hundred sixty-seven, 1186 and 1160 subjects aged nine, 13 and 16 years, respectively, responded to the questionnaire and had height, weight, skinfold thickness and blood pressure measured (response proportions of 83%, 79% and 78% respectively); 783, 818 and 874 subjects of the same age agreed to the blood draw (response proportions of 52%, 55% and 59%, respectively). Comparisons of characteristics of participants and nonparticipants in the blood draw showed few differences. The mean relative difference between lipoprotein and glucose values obtained at the study laboratory and a reference method varied from -0.3% to 6.1%. Design effects for means and proportions varied from 1.0 to 1.8., Conclusion: Despite its complexity, this survey was able to achieve a high level of precision for multiple measures. It will provide the most complete data on cardiovascular risk factors ever collected among children and adolescents in Canada.

Purpose: To examine the test retest reliability, internal consistency, and convergent construct validity of selected measures of nicotine dependence (ND) among adolescents., Methods: Self-reports of sociodemographic characteristics and smoking behavior were collected in a convenience sample of 238 high school students aged 13 to 19 years. ND was measured in the Hooked on Nicotine Checklist (HONC), the Stanford Dependence Index (SDI) and in 45 new items identified in consultation with experts and focus group interviews with adolescent smokers., Results: Test retest reliability among past 3-month smokers indicated good to excellent reliability coefficients for HONC items (kappa 0.61 to 0.93), except one item that tapped feelings of depression on withdrawal (kappa = 0.34). Intraclass correlation coefficients for SDI items ranged from 0.71 to 0.77. Test retest reliability coefficients for the 45 new items ranged from 0.20 to 0.90. The HONC and SDI demonstrated good internal consistency (Cronbach's alpha = 0.90 and 0.78, respectively). Convergent construct validity against cigarette exposure was demonstrated for the HONC, SDI, and most of the 45 new items., Conclusions: The HONC and SDI demonstrated excellent and good psychometric properties, respectively. Most of the 45 new items hold promise as indicators of ND in youth, and should be further investigated.