Cohort Profile: The Nicotine Dependence in Teens (NDIT) Study

Prospective associations between neighborhood features and body mass index in Montreal adolescents

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.

The application of target trials with longitudinal targeted maximum likelihood estimation to assess the effect of alcohol consumption in adolescence on depressive symptoms in adulthood

Time-varying confounding is a common challenge for causal inference in observational studies with time-varying treatments, long follow-up periods, and participant dropout. Confounder adjustment using traditional approaches can be limited by data sparsity, weight instability, and computational issues. The Nicotine Dependence in Teens Study is a prospective cohort study, and we used data from 21 data collection cycles carried out from 1999 to 2008 among 1294 students recruited from 10 high schools in Montreal, Quebec, Canada, including follow-up into adulthood. Our aim in this study was to estimate associations of timing of alcohol initiation and cumulative duration of alcohol use with depression symptoms in adulthood. Based on the target trials framework, we defined intention-to-treat and as-treated parameters in a marginal structural model with sex as a potential effect-modifier. We then used the observational data to emulate the trials. For estimation, we used pooled longitudinal target maximum likelihood estimation, a plug-in estimator with double-robust and local efficiency properties. We describe strategies for dealing with high-dimensional potential drinking patterns and practical positivity violations due to a long follow-up time, including modifying the effect of interest by removing sparsely observed drinking patterns from the loss function and applying longitudinal modified treatment policies to represent the effect of discouraging drinking.

A time compositional analysis of the association between movement behaviors and indicators of mental health in young adults

BACKGROUND

Movement behaviors (i.e., physical activity [PA], sedentary behaviors [SB], sleep) relate to mental health. Although movement behaviors are often analyzed as distinct entities, they are in fact highly inter-dependent (e.g., if an individual increases sleep, then PA and/or SB must be reduced) and these dependencies should be accounted for in the analysis. We tested whether perceptions of time spent in movement behaviors (i.e., moderate-to-vigorous intensity PA [MVPA], light physical activity [LPA], SB, and sleep) related to depressive symptoms and self-report mental health in young adults using a compositional analysis. We then estimated change in depressive symptoms with reallocation of time across movement behaviors using compositional time-reallocation models.

METHODS

Data were drawn from the longitudinal NDIT dataset. Complete data were available for 770 young adults (Mage  = 20.3, 55% females).

RESULTS

The proportion of time spent in MVPA relative to other movement behaviors related to depressive symptoms non-significantly and to mental health significantly. Reallocating 15 min from MVPA to SB resulted in a significant (0.46 unit) increase in depressive symptoms, and reallocating 15 min of MVPA to LPA was associated with a (0.57) increase in depressive symptoms.

CONCLUSION

These results indicate the importance of relative time spent in each movement behavior to mental health. Further research should examine these associations over time.

Predictors of Food and Physical Activity Tracking Among Young Adults

BACKGROUND

Monitoring food intake and physical activity (PA) using tracking applications may support behavior change. However, few longitudinal studies identify the characteristics of young adults who track their behavior, findings that could be useful in designing tracking-related interventions. Our objective was to identify predictors of past-year food and PA tracking among young adults.

METHODS

Data were available for 676 young adults participating in the ongoing longitudinal Nicotine Dependence in Teens Study. Potential predictors were measured in 2017-2020 at age 31, and past-year food and PA tracking were measured in 2021-2022 at age 34. Each potential predictor was studied in a separate multivariable logistic regression model controlling for age, sex, and educational attainment.

RESULTS

One third (37%) of participants reported past-year PA tracking; 14% reported past-year food, and 10% reported both. Nine and 11 of 41 potential predictors were associated with food and PA tracking, respectively. Compensatory behaviors after overeating, trying to lose weight, self-report overweight, reporting a wide variety of exercise behaviors, and pressure to lose weight predicted both food and PA tracking.

CONCLUSION

Food and PA tracking are relatively common among young adults. If the associations observed herein between compensatory behavior after overeating and tracking (among other observed associations) are replicated and found to be causal, caution may need to be exercised in making "blanket" recommendations to track food intake and/or PA to all young adults seeking behavior change.

Identifying high school smokers likely to persist in smoking at age 31

OBJECTIVE

Quitting smoking by the mid-30 s conveys important health benefits. Yet, although many smokers attempt to quit, few succeed. Identification of the characteristics of adolescent smokers most likely to continue smoking between ages 30 and 40 could help target early cessation efforts. Our objectives in this study were to (i) describe the course of smoking in a population-based sample of high school smokers into their 20 s and 30 s, and (ii) identify distal predictors of past-year cigarette smoking at age 31.

METHODS

Data at ages 17 (in 11th grade), 20, 24 and 31 were drawn from a 20-year longitudinal study of students ages 12-13 at inception, from 10 high schools in Montréal, Canada. Associations between 11 smoking-related characteristics measured in 11th grade and past-year smoking at age 31 were estimated in multivariable logistic regression models.

RESULTS

Among 244 11th grade smokers (67.4% female; 41% daily smokers), past-year smoking was reported by 71% at age 20, 68% at age 24, and 52% at age 31. Only 12% reported abstinence at ages 20, 24 and 31. Females were less likely than males to smoke at age 31. Parental smoking while the smoker was in 11th grade, use of other tobacco products, longer time since smoking onset, weekly or daily smoking, monthly cigarette consumption, and perceived nicotine addiction predicted past-year smoking at age 31.

CONCLUSIONS

In addition to preventive interventions, cessation programs targeting novice smokers in high school as soon as they begin smoking, are warranted.

Exergaming Among Young Adults in Canada: Longitudinal Study

BACKGROUND

Exergaming may be an important option to support an active lifestyle, especially during pandemics.

OBJECTIVE

Our objectives were: (i) to explore whether exergaming status from before to during the COVID-19 pandemic (stopped, started, sustained exergaming, never-exergamed) related to changes in walking, moderate-to-vigorous physical activity (MVPA), or meeting MVPA guidelines; and (ii) among past-year exergamers, to describe change in minutes/week exergaming from before to during the pandemic.

METHODS

681 participants (M(SD) age=33.6(0.5), 41% male) from the 22-year NDIT study provided data on walking, MVPA, and exergaming before (2017-20) and during the COVID-19 pandemic (2021). Physical activity (PA) change scores were described by exergaming status.

RESULTS

62.4% of participants never exergamed, 8.2% started exergaming during the pandemic, 19.7% stopped, and 9.7% sustained exergaming. Declines were observed in all three PA indicators in all four groups. Among the more salient findings: (i) participants who started exergaming during COVID-19 reported the highest MVPA levels before and during the pandemic and declined the least (mean -35 minutes/week) (ii) sustained exergamers reported the lowest MVPA levels during the pandemic (median 66 minutes/week), and they declined the most in MVPA (mean change of -92 minutes/week) and in meeting MVPA guidelines (-23.6%). During the pandemic, starters reported 85 minutes of exergaming/week and sustained exergamers increased exergaming by a median 60 minutes/week.

CONCLUSIONS

Although starting and sustaining exergaming did not appear to help exergamers maintain pre-pandemic PA levels, exergaming can contribute a substantial proportion of total PA in young adults and may still represent a useful option to promote PA during pandemics.

CLINICALTRIAL

Not applicable.

Health-Promoting School Culture: How Do We Measure it and Does it Vary by School Neighborhood Deprivation?

BACKGROUND

The context in which school-based health-promoting interventions are implemented is key for the delivery and success of these interventions. However, little is known about whether school culture differs by school deprivation.

METHODS

Using data from PromeSS, a cross-sectional study of 161 elementary schools in Québec, Canada, we drew from the Health Promoting Schools theoretical framework to develop four measures of health-promoting school culture (i.e., school physical environment, school/teacher commitment to student health, parent/community engagement with the school, ease of principal leadership) using exploratory factor analysis. One-way ANOVA with post-hoc Tukey-Kramer analyses was used to examine associations between each measure and social and material deprivation in the school neighborhood.

RESULTS

Factor loadings supported the content of the school culture measures and Cronbach's alpha indicated good reliability (range: 0.68-0.77). As social deprivation in the school neighborhood increased, scores for both school/teacher commitment to student health and parent/community engagement with the school decreased.

IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY

Implementation of health-promoting interventions in schools located in socially deprived neighborhoods may require adapted strategies to address challenges related to staff commitment and parental and community involvement.

CONCLUSION

The measures developed herein can be used to investigate school culture and interventions for health equity.

Genetic variation in fatty acid amide hydrolase (FAAH): Associations with early drinking and smoking behaviors

BACKGROUND

The endocannabinoid system is implicated in psychiatric disorders and drug dependence. Within this system, fatty acid amide hydrolase (FAAH) metabolizes endocannabinoids. Individuals with A-group genotypes (C/A or A/A) of a common FAAH variant (rs324420; C > A; Pro129Thr) have slower enzymatic activity compared to C-group individuals (C/C genotype). Slow FAAH activity is differentially associated with alcohol and nicotine use.

METHODS

Among European-ancestry participants in the NDIT study (n = 249-607), genotype associations with past-year binge drinking in young adults were estimated in logistic regression models. In adolescents, hazard ratios (HR) were estimated from Cox proportional hazards models to assess the FAAH genotype group association with time to drinking initiation and attaining drinking frequency outcomes. HR were also used to assess genotype effect on time to smoking initiation and attaining early smoking milestones (e.g., first inhalation, ICD-10 dependence).

RESULTS

Compared to those in the C-group, those in the A-group had higher odds of binge drinking at ages 20 (Odds ratio (OR) = 2.16, 95 % CI 1.36-3.42) and 30 (OR = 1.61, 95 % CI 1.10-2.36). Time to initiation of drinking and daily drinking was faster in adolescents in the A-group (HR = 1.39, 95 % CI 1.09-1.77 and HR = 2.24, 95 % CI 1.05-4.76, respectively). Time to smoking initiation was faster in the A-group (HR = 1.20, 95 % CI 1.04-1.39); however, time to smoking milestones among adolescent smokers was not consistently different for the A- versus C-groups (HR = 0.43 to 1.13).

CONCLUSIONS

Slow FAAH activity (A-group) was associated with greater risks for binge drinking, drinking initiation and escalation, and cigarette smoking initiation, but had little impact on the escalation in cigarette smoking behaviors.

Mediation by coping style in the association between stressful life events and depressive symptoms in young adults

PURPOSE

The association between stressful life events and depressive symptoms is well-established, but the role of coping style in this association is less clear. We examined whether problem-focused, emotion-focused or avoidant coping style mediated and/or moderated the association in young adults.

METHODS

Data were drawn from a 20-year longitudinal study that included 1294 students' age 12-13 years recruited in 1999-2000 from ten high schools in Montreal, Canada. Herein we report an analysis that included 782 participants aged 24 years on average with data on covariates collected at age 20. Using VanderWeele's four-way decomposition approach, the total effect of stressful life events on depressive symptoms considering coping styles was decomposed into four components: moderation only, mediation only, mediated interaction, no mediation or moderation.

RESULTS

We observed mediation only by emotion-focused coping ([Formula: see text](95%CI) = 0.15(0.04, 0.24)) suggestive that individuals who experienced more stressful life events also reported greater use of emotion-focused coping and higher levels of depressive symptoms. We found moderation only by problem-focused coping ([Formula: see text](95%CI) = - 1.51(- 2.40, - 0.53)) and by emotion-focused coping ([Formula: see text](95%CI) = 1.16(0.57, 1.69). These results suggest that individuals reporting more problem-focused coping experienced fewer depressive symptoms after exposure to stressful life events; those reporting more emotion-focused coping experienced more depressive symptoms. Avoidant coping did not mediate or moderate the association between stressful life events and depressive symptoms.

CONCLUSION

Interventions that aim to reduce depressive symptoms in young adults who experience stressful life events may need to reinforce problem-focused coping and minimize emotion-focused coping strategies.

Symptoms of depression and anxiety increased marginally from before to during the COVID-19 pandemic among young adults in Canada

We documented changes in depressive and anxiety symptoms from before to during the COVID-19 pandemic among young adults and investigated whether changes differed across participant characteristics. Data were available in an investigation of 1294 grade 7 students recruited in 1999–2000. For this analysis, we used data collected pre-pandemically in 2017–20 (mean (SD) age = 30.6 (1.0)) and during the pandemic in 2020–21 (mean (SD) age = 33.6 (0.6)). 673 participants with data in both cycles were retained for analysis. Symptoms were measured using the Major Depression Inventory (MDI) and the Generalized Anxiety Disorder-7 (GAD-7) scale. Standardized mean differences (SMD) of changes in MDI and GAD-7 values between cycles were calculated across participant characteristics. On average, MDI scores increased by 2.1 (95%CI 1.4, 2.8) points during the pandemic from mean 10.5; GAD-7 scores increased by 1.2 (0.8, 1.5) points from mean 4.7. The SMD was 0.24 (0.14, 0.33) for MDI, and 0.24 (0.13, 0.34) for GAD-7. No differences in MDI change scores were observed across participant characteristics. Differences in GAD-7 change scores were observed by mood/anxiety disorder (SMD − 0.31 (− 0.58, − 0.05)), household income (0.24 (0.02, 48)), living with young children (− 0.56 (− 1.23,− 0.05)), and adherence to public health recommendations 0.58 (0.19, 1.03)). Increases in depressive and anxiety symptoms were observed 10–16 months into the COVID-19 pandemic among adults age 32–36.

Predictors of past-year e-cigarette use among young adults

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Predictors of past-year e-cigarette use among young adults at age 30 were studied.

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Data was drawn from the Nicotine Dependence In Teens (NDIT) cohort.

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Male sex, friends smoke, tobacco and substance use, and impulsivity predicted use.

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Higher education and very good/excellent self-rated health were protective.

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These factors warrant consideration in public health efforts.

Understanding the underpinnings of e-cigarette use among young adults is critical to addressing increasing uptake. We identified predictors of past-year e-cigarette use among young adults in Montreal, Canada. Data on potential predictors were available for 714 young adults participating in the ongoing Nicotine Dependence in Teens Study at age 20 in 2007–08. Past-year e-cigarette use was measured at age 30 in 2017–20. Each potential predictor was studied in a separate multivariable logistic regression model controlling for age, sex, and educational attainment. Male sex, friends who smoke, cigarette smoking, use of other tobacco products, alcohol use, use of marijuana, and impulsivity predicted past-year e-cigarette use. Higher educational attainment and very good/excellent self-rated health were protective. Program and policy makers will need to consider these predictors of e-cigarette use in the design of clinical and public health interventions targeting e-cigarette use in young adults.

Does group-based trajectory modeling estimate spurious trajectories?

Background

Group-based trajectory modelling (GBTM) is increasingly used to identify subgroups of individuals with similar patterns. In this paper, we use simulated and real-life data to illustrate that GBTM is susceptible to generating spurious findings in some circumstances.

Methods

Six plausible scenarios, two of which mimicked published analyses, were simulated. Models with 1 to 10 trajectory subgroups were estimated and the model that minimized the Bayes criterion was selected. For each scenario, we assessed whether the method identified the correct number of trajectories, the correct shapes of the trajectories, and the mean number of participants of each trajectory subgroup. The performance of the average posterior probabilities, relative entropy and mismatch criteria to assess classification adequacy were compared.

Results

Among the six scenarios, the correct number of trajectories was identified in two, the correct shapes in four and the mean number of participants of each trajectory subgroup in only one. Relative entropy and mismatch outperformed the average posterior probability in detecting spurious trajectories.

Conclusion

Researchers should be aware that GBTM can generate spurious findings, especially when the average posterior probability is used as the sole criterion to evaluate model fit. Several model adequacy criteria should be used to assess classification adequacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01622-9.

Teenage Sport Trajectory Is Associated With Physical Activity, but Not Body Composition or Blood Pressure in Early Adulthood

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.

Does genetic variation in a bitter taste receptor gene alter early smoking behaviours in adolescents and young adults?

BACKGROUND AND AIMS

Variation in the TAS2R38 taste receptor gene alters the ability to taste bitter compounds. We tested whether TAS2R38 variation influences early smoking behaviours in adolescence, a critical period of acquisition when taste may influence the natural course of tobacco use.

DESIGN AND PARTICIPANTS

Observational study (Nicotine Dependence in Teens [NDIT]). Cox proportional hazards models were conducted using data from European ancestry adolescent participants who initiated smoking during follow-up (n = 219, i.e. incident smokers). In young adulthood, cross-sectional analyses were restricted to European ancestry self-reported current smokers at age 24 (n = 148).

SETTING

Montréal, Canada.

MEASUREMENTS

In adolescents, the rates of attaining early smoking milestones were estimated for tasters {PAV diplotypes (i.e. PAV/PAV or PAV/AVI)} versus non-tasters {AVI diplotype (i.e. AVI/AVI)}. In young adults, associations between tasting status and a nicotine intake biomarker (cotinine + 3'hydroxycotinine) and past-week cigarette consumption were assessed.

FINDINGS

Among incident smokers, similar rates to first whole cigarette were found between the diplotype groups (hazard ratio [HR], 1.05; 95% confidence interval (CI), 0.75-1.48; P = 0.765). However, smokers with the PAV (vs AVI) diplotypes attained monthly smoking more rapidly (HR, 1.55; 95% CI, 1.04-2.32; P = 0.033) and had faster conversion to three different measures of tobacco dependence (International Classification of Diseases: HR, 2.29; 95% CI, 0.99-5.28; P = 0.052; modified Fagerström Tolerance Questionnaire: HR, 3.02, 95% CI, 1.04-8.79; P = 0.043; Hooked on Nicotine Checklist: HR, 1.87; 95% CI, 0.98-3.60; P = 0.059). At age 24, those with PAV (vs AVI) diplotypes had higher mean cotinine + 3'hydroxycotinine (197 vs 143 ng/mL; P = 0.053).

CONCLUSIONS

Adolescents with a genetic variation increasing their ability to taste bitter compounds appear to escalate more quickly to monthly smoking and tobacco dependence during adolescence and have higher nicotine intake in young adulthood versus those without that genetic variation.

Stable physical activity patterns predominate in a longitudinal study of physical activity among young adults in Canada from before to during the COVID-19 pandemic

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Physical activity data were collected before and during the pandemic in young adults.

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63% of participants met physical activity guidelines at both timepoints.

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11% newly met guidelines and 25% no longer met guidelines during the pandemic.

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Using physical activity to cope during COVID-19 predicted meeting guidelines.

We examined change in walking, moderate-to-vigorous physical activity (MVPA) and meeting MVPA guidelines from before to during the COVID-19 pandemic, and identified factors associated with newly meeting and no longer meeting MVPA guidelines during the pandemic. Complete data were available for 614 young adults participating in the ongoing Nicotine Dependence in Teens (NDIT) study pre-pandemically in 2010–12 and 2017–20, and during the pandemic in 2020–21. Change in physical activity was examined in four sub-groups (i.e., stable inactive, newly met MVPA guidelines, no longer met MVPA guidelines, stable active). Factors associated with newly and no longer met MVPA guidelines were identified in multivariable logistic regression. While walking and MVPA changed little from 2010-2 to 2017–20, both declined during the pandemic (median for both = -30 min/week). 63.3% of participants reported no change in meeting MVPA guidelines during the pandemic, 11.4% newly met MVPA guidelines and 25.2% no longer met MVPA guidelines. Male sex, not university-educated, amotivated to engage in physical activity reported pre-pandemic, and endorsing physical activity as a COVID-19 coping strategy were associated with newly met MVPA guidelines. Male sex, not university-educated, higher problem-focused coping scores and endorsing physical activity as a COVID-19 coping strategy were protective of no longer met MVPA guidelines. Increased understanding of why some participants increased or decreased MVPA during the pandemic is needed to inform physical activity-related policy during pandemics.

Who mixes tobacco with cannabis and does mixing relate to nicotine dependence?

BACKGROUND

Cannabis users who mix tobacco with cannabis are exposed to nicotine in the tobacco. We identified characteristics of young adult cannabis users who mix and investigated whether mixing frequency is associated with nicotine dependence (ND).

METHODS

Data were collected in self-report questionnaires in 2017-20 from 788 young adults (44% male; mean (SD) age 30.6 (1.0) years) participating in a longitudinal investigation of the natural course of ND. Using multivariable logistic regression, we assessed whether any of 16 sociodemographic, lifestyle, psychosocial or other characteristics were associated with mixing among 313 past-year cannabis users. We also assessed whether mixing frequency was associated with ND among 289 past-year cannabis users who had ever smoked cigarettes controlling for age, sex, and other sources of nicotine (i.e., number of cigarettes smoked, other tobacco products, second-hand smoke exposure).

RESULTS

Of 788 participants, 40 % (n = 313) reported past-year cannabis use. Of these, 150 (48 %) reported mixing. Younger age, lower education and income, past-year cigarette use, use of other tobacco products and illicit drugs, poor coping skills and gambling were associated with mixing. Number of ICD-10 ND criteria endorsed was associated with mixing < weekly (b(95 % CI) = 0.3(0.02,0.7)) and weekly/daily (0.5(0.1,0.9)) after controlling for other sources of nicotine.

CONCLUSION

Mixing is associated with ND and therefore may threaten tobacco control efforts by rendering quitting cigarette smoking more difficult among smokers who mix tobacco with cannabis. Mixing tobacco with cannabis should be considered as an additional source of nicotine exposure in studies of ND in young people.

A longitudinal study of change in substance use from before to during the COVID-19 pandemic in young adults

Introduction

We assessed change in substance use from before to during the COVID-19 pandemic in young adults and identified factors associated with initiation/increase in use.

Methods

The sample comprised young adults from a longitudinal investigation of 1294 youth recruited at ages 12-13 (1999-2000) in 10 Montréal-area high schools. Pre-pandemic data on use of cannabis, alcohol, combustible cigarette, e-cigarette and binge drinking were collected at ages 20.4, 24.0 and 30.6. During COVID-19, data were collected from December 2020 to June 2021 (age 33.6). We studied the prevalence of any and weekly/daily use from age 20.4 to 33.6. Individual-level change in substance use during the pandemic was estimated as differences in the frequency of use from age 30.6 to 33.6 versus from age 24.0 to 30.6. Heterogeneity in the risk of initiated/increased substance use during COVID-19 across sociodemographic subgroups was assessed using modified Poisson regression.

Results

The prevalence of cannabis use increased from 17.5% to 23.1% from before to during the pandemic; e-cigarette use increased from 3.8% to 5.4%. In individual change analyses, the proportion of participants whose substance use did not change ranged from 48.9% (alcohol) to 84.0% (e-cigarettes). The incidence of initiated/increased cannabis use (22.4%), and quit/decreased alcohol (35.2%) and binge drinking (53.5%) were higher during the pandemic than between ages 24.0 to 30.6. Low education and living alone were associated with higher risks of initiated/increased use of most substances.

Discussion

Most participants reported stable patterns in substance use from before to during the COVID-19 pandemic.

Funding

The NDIT study was supported by the Canadian Cancer Society (grant numbers 010271, 017435, 704031) and the Canadian Institutes of Health Research (grant number 451832).

Revisiting trajectories of BMI in youth: An in-depth analysis of differences between BMI and other adiposity measures

OBJECTIVE

Body mass index (BMI) is used to identify trajectories of adiposity in youth, but it does not distinguish fat- from fat-free-mass. There are other inexpensive measures of adiposity which might better capture fat-mass in youth The objective of this study is to examine differences between sex-specific trajectories of BMI and other adiposity indicators (subscapular and triceps skinfold thickness, waist circumference, waist-to-height ratio) which may better capture fat-mass in youth.

METHODS

Data come from four cycles of a longitudinal cohort of 1293 students in Montréal, Canada at ages 12, 15, 17 and 24. Group-based trajectory models identified sex-specific adiposity trajectories among participants with data in ≥3 cycles (n = 417 males; n = 445 females).

RESULTS

There were six trajectory groups in males and females for all five indicators, except for waist circumference (seven) in both sexes and triceps skinfold thickness (four) and waist-to-height ratio (five) in females. Most trajectories indicated linear increases; only the skinfold thickness indicators identified a decreasing trajectory. While all indicators identified a trajectory with high levels of adiposity, they differed in the number and relative size of trajectories pertaining to individuals in lower half of the adiposity distribution.

CONCLUSION

BMI is a satisfactory indicator of adiposity in youth if the aim of the trajectory analysis is to identify youth with excess adiposity, a known risk factor for cardiometabolic outcomes in adulthood.

Fear appeal effectiveness in antismoking campaigns: do anger and smoking matter?

Although fear appeals are widely used in health campaigns, empirical studies have produced conflicting results regarding their effectiveness. To understand the impact of fear appeal in health campaigns, this study investigates the relationship between fear, anger, and smoking status in the context of an antismoking campaign. Using a survey of 829 people in South Korea, this study tests the three-way interactive model with the PROCESS macro. Results indicate that the effect of fear on attitudes toward the campaign depends on the level of anger, and show that the impact of 'anger-adjusted' additional fear appears only among nonsmokers. Implications for antismoking advertising strategies are discussed.

Association of Genetic Variants With Body-Mass Index and Blood Pressure in Adolescents: A Replication Study

The strong correlation between adiposity and blood pressure (BP) might be explained in part by shared genetic risk factors. A recent study identified three nucleotide variants [rs16933812 (PAX5), rs7638110 (MRPS22), and rs9930333 (FTO)] associated with both body mass index (BMI) and systolic blood pressure (SBP) in adolescents age 12-18years. We attempted to replicate these findings in a sample of adolescents of similar age. A total of 713 adolescents were genotyped and had anthropometric indicators and blood pressure measured at age 13, 15, 17, and 24years. Using linear mixed models, we assessed associations of these variants with BMI and SBP. In our data, rs9930333 (FTO) was associated with body mass index, but not systolic blood pressure. Neither rs16933812 (PAX5) nor rs7638110 (MRPS22) were associated with body mass index or systolic blood pressure. Although, differences in phenotypic definitions and in genetic architecture across populations may explain some of the discrepancy across studies, nucleotide variant selection in the initial study may have led to false-positive results that could not be replicated.

Cigarette smoking trajectories in adolescent smokers: Does the time axis metric matter?

INTRODUCTION

Most studies modeling adolescent cigarette smoking trajectories use age as the time axis, possibly obscuring depiction of the natural course of cigarette smoking. We used a simulated example and real data to contrast smoking trajectories obtained from models that used time since smoking onset or calendar time (age) as the time axis.

METHODS

Data were drawn from a longitudinal investigation of 1293 grade 7 students (mean age 12.8 years) recruited from 10 high schools in Montreal, Canada in 1999-2000, who were followed into young adulthood. Cigarette consumption was measured every 3 months during high school, and again at mean age 20.4 and 24.0. Analyses using time since onset of smoking as the time metric was restricted to 307 incident smokers; analysis using calendar time included 645 prevalent and incident smokers. Smoking status and nicotine dependence (ND) were assessed at mean age 20.4 and 24.0. Simulated data mimicked the real study during high school.

RESULTS

Use of different time metrics resulted in different numbers and shapes of trajectories in the simulated and real datasets. Participants in the calendar time analyses reported more ND in young adulthood, reflecting inclusion of 388 prevalent smokers who had smoked for longer durations.

CONCLUSIONS

Choosing the right time metric for trajectory analysis should be balanced against research intent. Trajectory analyses using the time since onset metric depict the natural course of smoking in incident smokers. Those using calendar time offer a snapshot of smoking across age during a given time period.

IMPLICATIONS

This study uses simulated and real data to show that trajectory analyses of cigarette smoking that use calendar time (e.g., age) versus time since onset as the time axis metric tell a different story. Trajectory analyses using the time since onset metric depict the natural course of smoking in incident smokers. Those using calendar time offer a snapshot of smoking across age during a given time period. Choosing the right time metric should be balanced against research intent.

Longitudinal associations between team sport participation and substance use in adolescents and young adults

BACKGROUND

Team sport participation contributes to positive outcomes, including increased physical activity, better mental health, and enhanced social engagement. However, longitudinal studies show that team sport participation during adolescence is also associated with unhealthy lifestyle habits, including harmful substance use behaviors. Our objectives were to examine these associations in an adolescent sample, assess differences between sexes, examine the association by sport type, and investigate whether associations carry into young adulthood.

METHOD

Over five years of high school participants reported team sport participation, smoking status, and frequency of alcohol use, three years post-high school participants reported the same behaviors as well as marijuana use.

RESULTS

Regression analyses accounting for individual clustering revealed that participation in team sport during high school was associated with an increased likelihood of current smoking in males and more frequent drinking in both sexes during adolescence. These relationships were strongest in individuals who participated in football. Further analyses revealed that team sport participation in high school was associated with an increased likelihood of more frequent binge drinking in young adulthood; however, team sport participation in young adulthood was associated with a decrease in the likelihood of cigarette smoking and marijuana use in young adulthood.

CONCLUSION

Overall, results confirm that team sport participation in adolescence is positively associated with substance use in adolescence, and this association differs by sex. However, team sport participation in young adulthood is negatively associated with harmful substance use. Further research is needed to understand if these trends generalize beyond White adolescents and young adults.

Association between pattern of team sport participation from adolescence to young adulthood and mental health

We examined relationships between pattern of team sport participation during the transition from adolescence to young adulthood (ie, non-participants, initiators, discontinuers, sustainers) and indicators of mental health. Data on team sport participation and mental health from high school to young adulthood were drawn from the longitudinal NDIT study. After controlling for demographics, physical activity, and previous mental health, one-way MANCOVA and ANCOVAs indicated that pattern of team sport participation was associated with stress, F(2,706) =8.28, p < .01, and coping, F(2,706) = 10.66, p < .01 in young adulthood. Compared to non-participants (24% of sample) or those who discontinued team sport after adolescence (51%), individuals who sustained team sport participation from adolescence to young adulthood (22%) reported lower stress and better coping levels. Bivariate regression analysis indicated that, compared to non-participants, team sport sustainers were less likely to experience panic disorder symptoms (OR =0.57, 95% CI [0.34, 0.94], p = .03). There were too few team sport initiators (2%) to be included in analyses. Sustained team sport participation during the transition from adolescence to young adulthood may promote better mental health. Further research is needed to ascertain causality and develop strategies to encourage individuals to join sport teams during adolescence and sustain participation while transitioning to young adulthood.

Antibiotic Resistance in Wastewater Treatment Plants and Transmission Risks for Employees and Residents: The Concept of the AWARE Study

Antibiotic resistance has become a serious global health threat. Wastewater treatment plants may become unintentional collection points for bacteria resistant to antimicrobials. Little is known about the transmission of antibiotic resistance from wastewater treatment plants to humans, most importantly to wastewater treatment plant workers and residents living in the vicinity. We aim to deliver precise information about the methods used in the AWARE (Antibiotic Resistance in Wastewater: Transmission Risks for Employees and Residents around Wastewater Treatment Plants) study. Within the AWARE study, we gathered data on the prevalence of two antibiotic resistance phenotypes, ESBL-producing E. coli and carbapenemase-producing Enterobacteriaceae, as well as on their corresponding antibiotic resistance genes isolated from air, water, and sewage samples taken from inside and outside of different wastewater treatment plants in Germany, the Netherlands, and Romania. Additionally, we analysed stool samples of wastewater treatment plant workers, nearby residents, and members of a comparison group living ≥1000 m away from the closest WWTP. To our knowledge, this is the first study investigating the potential spread of ESBL-producing E. coli, carbapenemase-producing Enterobacteriaceae, and antibiotic resistance genes from WWTPs to workers, the environment, and nearby residents. Quantifying the contribution of different wastewater treatment processes to the removal efficiency of ESBL-producing E. coli, carbapenemase-producing Enterobacteriaceae, and antibiotic resistance genes will provide us with evidence-based support for possible mitigation strategies.

Associations among physical activity tracking, physical activity motivation and level of physical activity in young adults

Whether physical activity (PA) tracking devices are associated with PA motivation in young adults is largely unknown. We compared total PA minutes per week, total minutes walking/week, meeting moderate-to vigorous PA guidelines, and past-year activity tracking across motivation cluster profiles among 799 young adults. Participants with "self-determined" profiles reported the highest total PA minutes/week followed by participants with "low intrinsic," "controlled self-determined," and "high external" profiles. A behavior regulation profile X activity tracking frequency interaction was not significant. Behavior regulation profiles may need to be considered in PA interventions using activity trackers.

Social inequalities in availability of health-promoting interventions in Québec elementary schools

Availability of health-promoting interventions (HPIs) may vary across schools serving students with different socioeconomic backgrounds. Our objectives were to describe social inequalities across elementary schools in: (i) level of importance that school principals attribute to 13 common health-related issues among students in their school; (ii) availability of HPIs within their school addressing eight health topics and (iii) (mis)alignment between perceived importance and HPI availability. Data were collected in telephone interviews with school principals in a convenience sample of 171 elementary schools (59% of 291 schools contacted). Schools were categorized as serving very advantaged, moderately advantaged or disadvantaged students. Principals reported how important 13 health issues were among students in their schools and provided data on HPI availability for 8 health issues, 4 of which required school action under government mandates. Higher proportions of principals in schools serving disadvantaged students (36% of all 171 schools) perceived most health issues as important. The mean number of HPIs in the past year was 12.0, 12.1 and 11.7 in schools serving very advantaged, moderately advantaged and disadvantaged students, respectively. Only availability of mental health HPIs differed by school deprivation (60, 43 and 30% in very, moderately and disadvantaged, respectively). Although most schools offered oral health HPIs, dental problems were not perceived as important. Smoking was perceived as not important and smoking-related HPIs were relatively rare (9%). Given rapid evolution in public health priorities, (mis)alignment between perceived importance of specific health issues and HPI availability in elementary schools warrants ongoing reflection.

Depressive Symptoms and Cigarette Smoking in Adolescents and Young Adults: Mediating Role of Friends Smoking

INTRODUCTION

We examined the mediating role of friends smoking in the association between depressive symptoms and daily/weekly cigarette smoking from adolescence into adulthood.

METHODS

Data were drawn from the Nicotine Dependence In Teens study (NDIT, Canada) and the Avon Longitudinal Study of Parents and Children (ALSPAC, UK) studies. Three age groups were investigated in NDIT: age 13-14 (n=1189), 15-16 (n=1107), and 17-18 (n=1075), and one in ALSPAC (n=4482, age 18-21). Multivariable mediation models decomposed the total effect (TE) of depressive symptoms on smoking into a natural direct effect (NDE) and natural indirect effect (NIE) through friends smoking.

RESULTS

The ORs for the TE were relatively constant over time with estimates ranging from 1.12 to 1.35. Friends smoking mediated the association between depressive symptoms and smoking in the two youngest samples (OR (95%CI) 1.09 (1.01,1.17) in 13-14-year-olds; 1.10 (1.03,1.18) in 15-16-year-olds). In the two older samples, NDE of depressive symptoms was close to the TE, suggestive that mediation was absent or too small to detect.

CONCLUSION

Friends smoking mediates the association between depressive symptoms and daily/weekly cigarette smoking in young adolescents.

IMPLICATIONS

If young adolescents use cigarettes to self-medicate depressive symptoms, then interventions targeting smoking that ignore depressive symptoms may be ineffective. Our results also underscore the importance of the influence of friends in younger adolescents, suggestive that preventive intervention should target the social environment including social relationships.

Contemporaneous trajectories of physical activity and screen time in adolescents

Adolescents often report low moderate-to-vigorous physical activity (MVPA) and high screen time. We modeled sex-specific MVPA and screen time trajectories during adolescence and identified contemporaneous patterns of evolution. Data were drawn from 2 longitudinal investigations. The Nicotine Dependence in Teens (NDIT) study included 1294 adolescents recruited at age 12-13 years who completed questionnaires every 3 months for 5 years. The Monitoring Activities of Teenagers to Comprehend their Habits (MATCH) study included 937 participants recruited at age 9-12 years who completed questionnaires every 4 months for 7 years. MVPA was measured as the number of days per week of being active for at least 5 min (NDIT) or 60 min (MATCH). In both studies, screen time was measured as the number of hours spent weekly in screen activities. In each study, sex-specific group-based trajectories were modeled separately for MVPA and screen time from grade 7 to 11. Contemporaneous patterns of evolution were examined in mosaic plots. In both studies, 5 MVPA trajectories were identified in both sexes, and 4 and 5 screen time trajectories were identified in boys and girls, respectively. All combinations of MVPA and screen time trajectories were observed. However, the contemporaneous patterns of evolution were favourable in 14%-31% of participants (i.e., they were members of the stable high MVPA and the lower screen time trajectories). Novelty: MVPA and screen time trajectories during adolescence and their combinations showed wide variability in 2 Canadian studies. Up to 31% of participants showed favourable contemporaneous patterns of evolution in MVPA and screen time. Using uniform methods for trajectory modeling may increase the potential for replication across studies.

Structural Conditions as Cause: Explaining the Rapid Rise in Youth E-Cigarette Use by Re-thinking Models of Addiction

Background: E-cigarette use has spread rapidly and widely among youth, to an extent that has surprised some researchers.Objectives: We suggest that this surprise is owing to a particular limitation in the dominant models of addiction - namely, a strong focus upon addictive substances as cause. We argue that the phenomenon at hand is easier to comprehend when less attention is placed upon preventing the use of specific substances and more upon what we identify as structural susceptibility to addiction instead.Results: Drawing upon neurobiology, history, public health theory, and social theory, we re-conceive addictive substances as mechanisms of escape from social structures that predispose whole societies to addiction.Conclusions/Importance: We argue that the surge in youth e-cigarette use in particular, as well as the phenomenon of addiction in general, are easier to comprehend if models of addiction are expanded to conceptualize the problem in its wider dimensions. We invite addictions researchers to join us in expanding the field's analytical view.

E-Cigarettes as a Growing Threat for Children and Adolescents: Position Statement From the European Academy of Paediatrics

As the tobacco epidemic has waned, it has been followed by the advent of electronic nicotine delivery devices (ENDS) primarily manufactured by the tobacco industry to try to recruit replacements for deceased tobacco addicts. This document sets out the ten recommendations of the European Academy of Paediatrics (EAP) with regard to e-cigarettes and children and young people (CYP). The EAP notes that nicotine is itself a drug of addiction, with toxicity to the foetus, child and adult, and were ENDS only to contain nicotine, their use to create a new generation of addicts would be rigorously opposed. However, e-cigarettes include numerous unregulated chemicals, including known carcinogens, whose acute and long term toxicities are unknown. The EAP asserts that there is incontrovertible evidence that the acute toxicity of e-cigarettes is greater than that of "traditional" tobacco smoking, and a variety of acute pulmonary toxicities, including acute lung injuries, have been recorded due to e-cigarettes usage. The chronic toxicity of e-cigarettes is unknown, but given the greater acute toxicity compared to tobacco, the EAP cannot assume that e-cigarettes are safer in the long term. The high uptake of e-cigarettes by CYP, including under-age children, is partly fuelled by deceitful marketing and internet exposure, which is also unregulated. Although proposed as aids to smoking cessation, there is no evidence that e-cigarettes add anything to standard smoking cessation strategies. In summary, the EAP regards these devices and liquids as very dangerous, and ineluctably opposed to their use, and their direct or indirect marketing.

Depression symptoms and night eating in young adulthood

PURPOSE

We estimated cross-sectional and longitudinal associations between depression symptoms and night eating in young adults.

METHODS

Data were drawn from a longitudinal investigation of students age 12-13 years at inception in 1999-2000, in Montreal, Canada. Depression symptoms were measured with the Depressive Symptoms Scale (DSS) 20 times from age 12 to 17, and with the Major Depression Inventory (MDI) post-high school at ages 20 and 24. Night eating was measured at age 24. The association between depression symptoms and night eating was estimated in multivariable logistic regression models adjusted for sex, age and mother university-educated.

RESULTS

9% of 829 participants (n = 77) reported night eating. In cross-sectional analysis, the adjusted odds ratio (OR) estimate for MDI scores (range 0-50) was 1.04 (1.01, 1.07). In longitudinal analyses, the OR estimates were 1.75 (1.20, 2.55) for DSS scores (range 1-4) and 1.03 (1.002, 1.06) for the MDI.

CONCLUSIONS

Depression symptoms are associated with night eating in young adults cross-sectionally and possibly longitudinally. Treatment of depression symptoms may be important in preventing night eating, a core symptom of the Night Eating Syndrome.

LEVEL OF EVIDENCE

Level III, cohort analytic study.

Cigarette Smoking and Nicotine Dependence Trajectories Among Incident Adolescent Smokers

INTRODUCTION

Few interventions target adolescent cigarette smokers to prevent escalation in cigarette use or promote cessation, in part because little is known about co-developing smoking and nicotine dependence (ND). Our objectives were to: (1) estimate developmental trajectories of ND/cravings, withdrawal symptoms, the modified Fagerström Tolerance Questionnaire (mFTQ) and ICD-10 tobacco dependence in incident adolescent smokers; (2) describe concordance in number and shapes of trajectories across the four ND indicators; and (3) classify participants in each ND trajectory according to cigarette smoking trajectories.

METHODS

Data were drawn from an ongoing longitudinal investigation of 1294 grade 7 students recruited in 1999-2000 in 10 Montreal-area high schools. Group-based joint trajectory models were used to identify distinct subgroups defined by the four ND indicators, in 307 incident smokers.

RESULTS

The optimal trajectory model included five groups for ND/craving and four groups for each of withdrawal symptoms, the mFTQ and ICD-10 tobacco dependence. The four ND indicators showed similar developmental patterns and classification into smoking trajectory groups, although some discordance was observed. Smokers in the low-level decreaser group and stable low consumers who exhibited high ND were younger than those in the cigarette-low ND trajectory groups. Moderate or rapid escalators who exhibited no/low ND were less likely to have university-educated mothers and more likely to have parents who smoke.

CONCLUSIONS

Trajectories were similar across ND indicators, and generally reflected cigarette smoking trajectory shapes. Novice smokers may need education to become self-aware of developing ND symptoms, as well as to learn about alternative courses of action once ND symptoms manifest.

IMPLICATIONS

Trajectories of cigarette smoking and ND symptoms have rarely been investigated concurrently. This study provides evidence of high concordance across four distinct ND indicators in the proportion of participants with no/low-level dependence, and with high or increasing ND. Moreover, the development of cigarette smoking is concordant with ND symptom development. Interventions to prevent escalation and promote cessation should target adolescents before first puff to increase self-awareness of developing ND symptoms, as well as to learn about alternative courses of action once ND symptoms are experienced.

Discrete time measures versus trajectories of drinking frequency across adolescence as predictors of binge drinking in young adulthood: a longitudinal investigation

OBJECTIVES

We compared discrete time measures with trajectories of adolescent drinking frequency as predictors of sustained binge drinking in young adulthood.

DESIGN

Prospective longitudinal study.

SETTING

10 high schools in Montréal, Canada.

PARTICIPANTS

1293 high-school students followed from mean (SD) age 12 (0.6) to 24 (0.7) years.

PRIMARY OUTCOME MEASURES

Patterns of drinking frequency (self-reports every 3 months from ages 12 to 17) identified using group-based trajectory modelling. Sustained binge drinking was defined as binging monthly or more often at both ages 20 and 24.

ANALYSES

Using logistic regression, sustained binge drinking was regressed on trajectory group membership and on four discrete time measures (frequency of drinking at age 12; frequency of drinking at age 17; age at drinking onset; age at onset of drinking monthly or more often).

RESULTS

We identified seven drinking trajectories: late triers (15.2%), decreasers (9.5%), late escalators (10.4%), early slow escalators (16.5%), steady drinkers (14.4%), early rapid escalators (15.8%) and early frequent drinkers (18.2%). Sustained binge drinking was reported by 260 of 787 participants (33.0%) with complete data at both ages 20 and 24. Decreasers did not differ from late triers; all other patterns were associated with higher odds of sustained binge drinking (adjusted ORs: AORs=1.4-17.0). All discrete time measures were associated with sustained binge drinking, notably frequency at age 12 (a bit to try and drinking monthly: (AORs=2.6 (1.7; 3.9) and 2.8 (1.3; 6.1), respectively), age of drinking onset <13 years (AOR=7.6 (3.0; 24.1)), and any age of onset of drinking monthly or more often (AORs=5.1-8.2).

CONCLUSION

Youth at risk of sustained binge drinking as young adults can be identified with indicators of early drinking as early as 7th grade (aged 12-13 years). Identification of easy-to-obtain indicators can facilitate screening and intervention efforts.

The Natural Course of Cigarette Smoking among Adolescent Daily Smokers in France and Quebec

Objective:

To describe the natural course of cigarette smoking and nicotine dependence (ND) over 1-year in daily smokers ages 15 to 17 living in different social contexts.

Method:

Cigarette smoking and ND indicators were measured at baseline and 3- and 12-months thereafter among 95 daily smokers with a total of 123 observations from the Nicotine Dependence in Teens (NDIT) Study in Quebec, Canada, and in 111 daily smokers from the TABagisme chez les ADOlescents (TABADO) Study in Lorraine, France.

Results:

NDIT and TABADO participants initiated smoking a mean (SD) of 3.9 (1.6) and 3.7 (2.0) years prior to baseline, respectively. Despite baseline differences in age, sex, age at initiation, number of cigarettes smoked per day and social context, 85% of participants in both samples reported cravings and responded “yes” to “felt like you really need a cigarette”. Mean (SD) number of cigarettes smoked per day increased from 9.4 (8.1) to 11.8 (8.0) over 1 year in NDIT (adjusted mean difference (95% CI) = 2.4 (0.8, 3.0)), and from 11.5 (6.5) to 13.5 (6.7) in TABADO (adjusted mean difference (95% CI) = 2.0 (0.8, 3.1)). However, most ND indicators in both samples were stable over time and cessation was infrequent.

Conclusion:

Despite notable differences across samples, the natural course of cigarettes smoked per day, ND symptoms and cessation was similar, suggestive of an underlying biologic rather than social process. To quit, adolescents who smoke daily will likely need (pharmacologic) intervention to counter the biological mechanisms underpinning ND, as well as complementary strategies targeting the social context such as creating social environments favoring cessation success.

Does use of other tobacco products change when cigarette smoking status changes: A descriptive study of young adults

BACKGROUND

Whether polytobacco use or nicotine dependence (ND) change when cigarette smoking status changes in young adults is an understudied issue. Our objective was to describe use of other tobacco products (OTPs) and ND according to change in cigarette smoking status over four years in young adults.

METHODS

We drew data from a longitudinal study of 1294 adolescents age 12-13 at inception in 1999-2000 and followed into young adulthood. Among 790 participants with data at age 20 and 24, 22% had never smoked cigarettes; 37% were "sustained smokers"; 9% were "relapsers"; 10% had quit 1-3 years ago; and 22% had quit ≥4 years ago. We described past-year OTP (i.e., cigars/cigarillos, waterpipe, sundry tobacco products (i.e., pipe, bidis, chewing tobacco, snuff)) use and ND over 4 years in these groups.

RESULTS

At age 20, sustained smokers reported using a mean(SD) of 1.1(0.9) OTP in the past-year; relapsers reported 0.5(0.6); shorter-term quitters reported 0.9(0.7); longer-term quitters reported 0.3(0.6); and never smokers reported 0.2(0.4). There was no change in OTP use or ND in never smokers and longer-term quitters. Shorter-term quitters reduced the number of OTPs by -0.5(95% confidence interval: -0.7,-0.3) on average over 4 years; sustained smokers decreased by -0.2(-0.3,-0.1). Relapsers increased by 0.6(0.4,0.7) on average.

CONCLUSIONS

OTP use and ND were stable in early adulthood among never smokers, sustained smokers and longer-term quitters, but fluctuated in parallel with stopping and starting to smoke. Research is needed to ascertain the underpinnings of these fluctuations and whether they help or hinder cessation.

Mediating role of body-related shame and guilt in the relationship between weight perceptions and lifestyle behaviours

INTRODUCTION

A substantial proportion of individuals with overweight or obesity perceive themselves as 'too heavy' relative to 'about right'. Perceiving one's weight as 'too heavy' is associated with lower levels of physical activity and higher levels of sedentary behaviour. However, the mechanisms underpinning the associations between weight perception and lifestyle behaviours have not been identified. Based on theoretical tenets and empirical evidence, the self-conscious emotions of shame and guilt may mediate these associations.

METHODS

Participants were young adults (n = 618, Mage = 24.0 ± .6 years) who provided data on weight, weight perception, body-related shame and guilt, physical activity and screen time.

RESULTS

Mediation analyses using the PROCESS macro indicated that shame and guilt significantly mediated the relationships between weight perception and physical activity and shame significantly mediated the relationship between weight perception and screen time.

CONCLUSIONS

These findings provide preliminary evidence that self-conscious emotions may be mechanisms by which weight perception influences physical activity and sedentary behaviour in young adults. However, longitudinal investigations of this mechanism are needed.

Development and Validation of the Reasons to Exergame (RTEX) Scale in Young Adults: Exploratory Factors Analysis

Background

Exergaming is associated with positive health benefits; however, little is known about what motivates young people to exergame.

Objective

This study aimed to develop a new Reasons to Exergame (RTEX) scale and describe its psychometric properties (Study 1) including test-retest reliability (Study 2). We also examined the test-retest reliability of self-report exergaming behavior measures (Study 2).

Methods

We identified scale items in consultation with experts. In Study 1, we conducted an Exploratory Factor Analysis of RTEX and examined how the factors identified relate to exergaming frequency and intensity in a population-based sample of 272 young adults. In Study 2, we examined the test-retest reliability of RTEX factors and self-report measures of past-week exergaming frequency and intensity among 147 college students.

Results

We identified four factors in RTEX: exergaming for fitness, exergaming for enjoyment, preferring exergaming over other gaming options, and choosing exergaming over competing interests (eg, sports). Test-retest reliability of RTEX factors (ICC 0.7-0.8) and self-report exergaming frequency (ICC 0.4-0.9) was adequate. Exergaming for fitness and enjoyment were positively associated with the frequency of exergaming with friends and family, and with exergaming intensity. Preferring exergaming over other gaming options and choosing exergaming over competing interests (eg, sports) were not related to exergaming behavior.

Conclusions

RTEX is a psychometrically sound scale with four factors that measure reasons to exergame. Replication of these findings is needed in larger, more diverse samples.

Type of e-liquid vaped, poly-nicotine use and nicotine dependence symptoms in young adult e-cigarette users: a descriptive study

BACKGROUND

Data are lacking on type of e-liquid vaped among e-cigarette users. Further, few studies assess all sources of nicotine used by e-cigarette users to assess whether poly-nicotine use relates to nicotine dependence (ND). The objectives were to describe young adult e-cigarette users by: (i) type of e-liquid vaped; (ii) poly-nicotine use; (iii) ND symptoms; and (iv) attempts to quit conventional cigarettes.

METHODS

Data were available in cycle 23 of a longitudinal investigation on the natural course of cigarette smoking and ND. A total of 775 young adults (44% male; mean (SD) age 30.5(1.0)) completed mailed self-report questionnaires in 2017-20.

RESULTS

Of 775 participants, 149 (19.2%) reported past-year e-cigarette use. Overall, 55.0% of e-cigarette users had used cannabis-containing e-liquid (31.5% vaped cannabis e-liquid exclusively); 50.4% used nicotine-containing e-liquid (23.5% vaped nicotine e-liquid exclusively); and 39.9% used e-liquid without nicotine (8.7% vaped e-liquid without nicotine exclusively). Most e-cigarette users (82.6%) used other nicotine-containing products including conventional cigarettes (72.5%); 60.8% reported ND symptoms, rising to 79.4% among those who vaped nicotine-containing e-liquid. Finally, 29.0% tried to quit conventional cigarettes using e-cigarettes in the past-year, but only 16.7% found them helpful.

CONCLUSIONS

E-cigarettes now appear to appeal to a broader market than smokers who want to quit. More than half of young adult e-cigarette users vaped cannabis-containing e-liquid in the past year while only one-quarter had used e-cigarettes to assist with cessation. Most e-cigarette users used multiple nicotine-containing substances (including combustible cigarettes) which were associated with reports of ND symptoms.

Sampling sports during adolescence, exercise behaviour in adulthood, and the mediating role of perceived variety in exercise

Objective: Physical activity levels decline from adolescence to adulthood, but participation in a variety of sports during childhood and adolescence (i.e., sampling) may increase physical activity behaviour during adulthood. We examined the association between sampling sports during adolescence and moderate-vigorous exercise behaviour in adulthood, and we assessed whether this relationship is mediated by perceived variety in exercise. Design: Study 1- prospective longitudinal; Study 2- cross-sectional. Our main outcome was exercise behaviour. Results: In study 1 (n = 775), sampling more sports during adolescence (b = .25, p < .01; 95% CI [.12, .39]) predicted increased frequency of exercise behaviour in young adulthood. In study 2 (n = 108), sampling more sports in adolescence (β = .08, p = .03; 95% CI [.03, .17]) was indirectly associated with exercise behaviour in adulthood through perceived variety in exercise. Conclusion: These findings add to the evidence that sampling sports during adolescence is positively associated with moderate-vigorous exercise during adulthood, and the experience of variety may, in part, explain this relationship. This research generates new hypotheses regarding a potential psycho-social mediator (perceived variety in exercise) of the sampling-exercise behaviour relationship.

Untangling Influences in the Longitudinal Relationship Between Depressive Symptoms and Drinking Frequency in High School

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.

Intensity and frequency of physical activity and high blood pressure in adolescents: A longitudinal study

Despite limited evidence on the association between physical activity (PA) and blood pressure (BP) in youth, experts recommend that adolescents engage regularly in moderate-to-vigorous PA. We examined the relationships between PA intensity and frequency and the likelihood of having high BP in a population-based cohort of adolescents from Montréal, Canada. PA was self-reported every 3 months from grade 7 to 11, and BP was measured at ages 12.8, 15.2, and 17.0 years on average. We analyzed data from 993 participants (mean [SD] age = 16.0 [1.0], 51.6% female) with BP data at ages 15.2 and/or 17.0 years, using pooled ordinal logistic regression. BP (normal/elevated/hypertensive range) was the outcome, and past-year PA intensity and frequency were potential predictors. Eight percent of participants had elevated BP (120-129/<80), and 3.2% had BP in the hypertensive range (≥130/≥80). Participants engaged in a median (interquartile range) of 7.0 (4.5, 9.3) and 5.5 (2, 10.8) moderate and vigorous PA sessions/week, respectively. After adjusting for age, sex, mother's education, use of alcohol and cigarette consumption, engaging in PA more intense than light during the previous year was associated with a lower odds of having BP in the hypertensive range (ORs [95% CIs] = 0.93 [0.88, 0.97] to 0.97 [0.94, 0.99]). The relationships were not altered by adjusting for BMI. Our findings support recommendations that adolescents engage in at least moderate PA on a regular basis to prevent development of BP in the hypertensive range.

Measures of nicotine dependence enhance interpretation of number of cigarettes smoked in youth smoking surveillance

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.

Early Risk Factors for Daily Cannabis Use in Young Adults

OBJECTIVES

Daily cannabis use can portend problematic use or dependence. We aimed to identify early risk factors for daily cannabis use in young adults.

METHODS

Data were available in a longitudinal investigation of 1294 grade 7 students age 12 to 13 years at inception recruited in 10 secondary schools in Montreal, Canada, in 1999. Data on daily cannabis use were collected in mailed self-report questionnaires from 878 participants (67.9% of 1294) at age 20. The associations between each of 23 potential risk factors measured in grade 7 and daily cannabis use at age 20 were modeled using logistic regression.

RESULTS

At age 20, 44% of participants reported past-year cannabis use; 10% reported daily use. Older age; male sex; higher levels of family stress and other stress; use of alcohol, cigarettes, and other tobacco products; parent(s), sibling(s), and friend(s) smoke cigarettes; higher body mass index; higher impulsivity and novelty seeking; and lower self-esteem increased the odds of daily cannabis use.

CONCLUSIONS

Children at risk of daily cannabis use as young adults can be identified early. They may benefit from early intervention to prevent problematic cannabis use.

The Role of the Subjective Importance of Smoking (SIMS) in Cessation and Abstinence

Introduction

Each year about two thirds of U.S. smokers make a quit attempt. Yet, less than 5% remain abstinent three months post-quit date. One factor that may affect abstinence is negative feelings about the self-associated with being a smoker (disequilibrium), particularly if smoking is important to the sense of self and one is trying to quit.

Aims

We evaluated a multivariate structural equation model proposing that smoking's subjective importance to a smoker would influence carbon monoxide verified smoking abstinence at 24 weeks (post-quit date). Further, we assessed whether the relation would be moderated by the smoker's experience of disequilibrium.

Methods

Participants were 440 regular smokers taking part in a clinical trial assessing the effectiveness of different durations of nicotine replacement therapy use. Participants completed the subjective importance of smoking survey at baseline and were assessed for carbon monoxide verified seven-day point prevalence abstinence at 24 weeks.

Results

Using exploratory structural equation modelling, the subjective importance of smoking was associated with point prevalence abstinence at 24 weeks, but only for smokers with high disequilibrium.

Conclusions

The results of this study suggest that experiencing negative feelings about being a smoker could motivate smokers to remain abstinent, despite the importance of smoking to the smoker's sense of self.

Parental Cannabis Use Is Associated with Cannabis Initiation and Use in Offspring

OBJECTIVES

To assess, before legalization in Canada, whether parental cannabis use is associated with initiation of use in adolescent offspring or with use in young-adult offspring.

STUDY DESIGN

Data were available in 2 longitudinal studies in Montréal, Canada. In AdoQuest, 1048 parents with children in grade 6 reported past-year cannabis use. Cannabis initiation among offspring was measured in grade 7, 9, and/or 11. In the Nicotine Dependence in Teens study, cannabis use data were available for 584 participants (mean age 24 years) and their parents (ie, 542 offspring-mother pairs, 438 offspring-father pairs). The association between parental and offspring cannabis use was estimated using multivariable logistic regression in both studies.

RESULTS

In AdoQuest, grade 6 never-users were 1.8 times more likely to initiate cannabis during high school if their parents reported past-year use. In the Nicotine Dependence in Teens study, the aORs (95% CI) for past-year cannabis use among adult offspring were not different for "mother uses cannabis" (2.8 [1.4-5.8]) or "father uses cannabis" (2.1 [1.2-3.8]). Participants with 1 or 2 cannabis-using parents were 1.7 and 7.1 times more likely to use cannabis, respectively, than participants with non-using parents.

CONCLUSIONS

To enable informed decision-making about their own cannabis use, parents need to be aware that children of cannabis users are more likely to use cannabis in adolescence and young adulthood.

Link between Physical Activity Type in Adolescence and Body Composition in Adulthood

PURPOSE

We investigated whether type of physical activity (PA) (sports, running, and fitness/dance) engaged in during adolescence is associated with body composition in late adolescence or early adulthood.

METHODS

Data were drawn from 631 participants in the Nicotine Dependence in Teens study, a prospective investigation of students ages 12-13 yr at inception. Self-report PA data were collected at baseline, in grade 7, and every 3-4 months thereafter during the 5 yr of high school (1999-2005). Anthropometric indicators (height, weight, waist circumference, triceps, and subscapular skinfold thickness) were measured at ages 12, 16, and 24 yr. On the basis of prior exploratory factor analysis, PA was categorized into one of three types (sports, running, and fitness/dance). Regression models estimated the association between number of years participating in each PA type (0-5 yr) during high school and body composition measures in later adolescence or early adulthood.

RESULTS

In multivariable models accounting for age, sex, and parent education, more number of years participating in running during adolescence was associated with lower body mass index, waist circumference, and skinfold thickness in later adolescence and early adulthood (all P < 0.01). This association was no longer apparent in models that accounted for body composition at age 12 yr. The number of years participating in sports was positively associated with body mass index in early adulthood (P = 0.02), but fitness/dance was not statistically significantly associated with any outcome.

CONCLUSION

Sustaining participation in running, but not in other PA types, during adolescence was related to lower body composition in later adolescence and adulthood. However, more research is needed to determine whether this association is attributable to a relationship between PA and body composition in early adolescence.

A Tool to Identify Adolescents at Risk of Cigarette Smoking Initiation

: media-1vid110.1542/5828318368001PEDS-VA_2017-3701Video Abstract OBJECTIVES: To describe the development of a prognostic tool to identify adolescents at risk for transitioning from never to ever smoking in the next year.

METHODS

Data were drawn from the Nicotine Dependence in Teens study, a longitudinal investigation of adolescents (1999 to present). A total of 1294 students initially age 12 to 13 years were recruited from seventh-grade classes in 10 high schools in Montreal. Self-report questionnaire data were collected every 3 months during the 10-month school year over 5 years (1999-2005) until participants completed high school (n = 20 cycles). Prognostic variables for inclusion in the multivariable analyses were selected from 58 candidate predictors describing sociodemographic characteristics, smoking habits of family and friends, lifestyle factors, personality traits, and mental health. Cigarette smoking initiation was defined as taking even 1 puff on a cigarette for the first time, as measured in a 3-month recall of cigarette use completed in each cycle.

RESULTS

The cumulative incidence of cigarette smoking initiation was 16.3%. Data were partitioned into a training set for model-building and a testing set to evaluate the performance of the model. The final model included 12 variables (age, 4 worry or stress-related items, 1 depression-related item, 2 self-esteem items, and 4 alcohol- or tobacco-related variables). The model yielded a c-statistic of 0.77 and had good calibration.

CONCLUSIONS

This short prognostic tool, which can be incorporated into busy clinical practice, was used to accurately identify adolescents at risk for cigarette smoking initiation.

Sex Differences in Attaining Cigarette Smoking and Nicotine Dependence Milestones Among Novice Smokers

There may be sex differences in the response to nicotine, according to findings of studies in animals; however, sex differences in the natural course of cigarette smoking and nicotine dependence are documented in few studies. Prevalent (n = 240 girls; n = 184 boys) and incident (n = 231 girls; n = 184 boys) cigarette smokers from the Nicotine Dependence in Teens Study were followed up to 5 years after first puff, from age 12 to 18 years (1999-2005). We used Cox proportional hazards models to compare time to development of 3 cigarette-use (i.e., whole cigarette; 100 cigarettes lifetime; regular smoking), and 3 nicotine-dependence symptom (i.e., "really need a cigarette"; mentally addicted; physically addicted) milestones across sex. Girls were at higher risk than boys of attaining all milestones; hazard ratios (95% confidence intervals) ranged from 1.35 (1.06, 1.72) for 100 cigarettes lifetime to 1.74 (1.44, 2.10) for "really need a cigarette." Among nonregular smokers, 26% (8%; 43%) and 25% (6%; 44%) more girls than boys reported "really need a cigarette" 1 and 2 years, respectively, after first puff. Preventive interventions may need adjustment to incorporate these findings. Additional research should clarify the relative contribution of biological and social underpinnings of these sex differences.

Reasons for quitting smoking in young adult cigarette smokers

BACKGROUND

Although most young adult smokers want to quit smoking, few can do so successfully. Increased understanding of reasons to quit in this age group could help tailor interventions, but few studies document reasons to quit in young adults or examine reasons to quit by smoker characteristics.

METHODS

In 2011-12, 311 current smokers (age 22-28, M=24.1; 48.9% male, 51.1% female; 50.4% daily smokers) from the Nicotine Dependence in Teens Study completed the Adolescent Reasons for Quitting scale. We assessed differences in the importance of 15 reasons to quit by sex, education, smoking frequency, quit attempt in the past year, perceived difficulty in quitting, and motivation to quit. We also examined differences between participants who discounted the importance of long-term health risks and those who acknowledged such risks.

RESULTS

Concerns about getting sick or still smoking when older were considered very important by >70% of participants. Median scores were higher among daily smokers, those who had tried to quit or who expressed difficulty quitting, and those with strong motivation to quit. Discounters (14.5% of participants) were primarily nondaily, low-consumption smokers. Their Fagerström Test for Nicotine Dependence scores did not differ from non-discounters', and 11% (vs. 35.7% of non-discounters) were ICD-10 tobacco dependent.

CONCLUSIONS

Novel smoking cessation interventions are needed to help young adult smokers quit by capitalizing on their health concerns. Discounters may need educational intervention to better understand the impact of even "light" smoking on their health before or in conjunction with quit interventions.

Sex-specific trajectories of systolic and diastolic blood pressure in youth

BACKGROUND AND OBJECTIVE

High blood pressure early in life is associated with cardiovascular disease morbidity and mortality in adulthood. The objective was to identify sex-specific trajectories of SBP and DBP from early adolescence to early adulthood and to assess the impact of modifiable factors on the trajectories, including BMI, smoking, alcohol use, physical activity, and screen-time.

METHODS

Data were drawn from four waves of a prospective investigation of 1294 youth aged 12-13 years at inception and followed until age 24 years. Group-based trajectory models were used to identify trajectories and assess the impact of modifiable factors in 403 men and 432 women.

RESULTS

Three SBP trajectories were identified in men [corresponding to low (43.2%), medium (45.2%), and high SBP (11.7%)] and women [corresponding to low (48.1%), medium (44.7%), and high SBP (7.2%)]. Similar results were observed for DBP in both sexes. BMI and smoking were associated with higher SBP and DBP values in most trajectory groups, whereas screen-time in both sexes and physical activity in women were associated with high SBP trajectories only.

CONCLUSION

There is heterogeneity in the sex-specific natural course of SBP and DBP in youth and in the magnitude of the effect of modifiable factors on SBP and DBP across trajectories. Distinguishing trajectories allows identification of subgroups at risk of hypertension and cardiovascular disease later in life and in addition can inform the design of targeted interventions to attenuate high SBP and DBP trajectories over time and maintain normal trajectories.