Biomedical subjects

Janet Audrain-McGovern

Publications and source records attributed to Janet Audrain-McGovern.

At least 19 recordsLinked to original sources

PubMed2006

The role of CYP2A6 in the emergence of nicotine dependence in adolescents.

OBJECTIVES: The objectives of our study were to evaluate whether genetic variation in nicotine metabolic inactivation accounted for the emergence of nicotine dependence from mid- to late adolescence and whether initial smoking experiences mediated this effect. METHODS: Participants were 222 adolescents of European ancestry who participated in a longitudinal cohort study of the biobehavioral determinants of adolescent smoking. Survey data were collected annually from grade 9 to the end of grade 12. Self-report measures included nicotine dependence, smoking, age first smoked, initial smoking experiences, peer and household member smoking, and alcohol and marijuana use. DNA collected via buccal swabs was assessed for CYP2A6 alleles that are common in white people and are demonstrated to decrease enzymatic function (CYP2A6*2, *4, *9, *12). RESULTS: Latent growth-curve modeling indicated that normal metabolizers (individuals with no detected CYP2A6 variants) progressed in nicotine dependence at a faster rate and that these increases in nicotine dependence leveled off more slowly compared with slower metabolizers (individuals with CYP2A6 variants). Initial smoking experiences did not account for how CYP2A6 genetic variation impacts nicotine dependence. CONCLUSIONS: These findings may help to promote a better understanding of the biology of smoking behavior and the emergence of nicotine dependence in adolescents and inform future work aimed at understanding the complex interplay between genetic, social, and psychological factors in adolescent smoking behavior.

Adolescent↗

PubMed2006

Effect of team sport participation on genetic predisposition to adolescent smoking progression.

CONTEXT: There is much to be learned about why some adolescents progress to a regular smoking habit and others do not. OBJECTIVE: To evaluate whether (1) team sport participation buffers the effect of having 2 smoking risk genotypes (the dopamine reuptake transporter [SLC6A3] and the dopamine D(2) receptor [DRD2]) or 1 of these risk genotypes vs having none on adolescent smoking progression and (2) the buffering effects of team sports were due to physical activity associated with team sport participation. DESIGN: Longitudinal cohort study. Survey data were collected annually from grade 9 to the end of grade 12. Self-report measures included smoking, team sport participation, physical activity, depression, smoking exposure, and alcohol and marijuana use. DNA was collected via buccal swabs. Data were analyzed using latent growth modeling. SETTING: Five public high schools in Virginia. PARTICIPANTS: A total of 361 students of European ancestry. Main Outcome Measure Smoking progression. RESULTS: For adolescents participating in at least 1 team sport, but not for adolescents with no team sport participation, physical activity had a significant negative effect on smoking progression (z = -3.85, P<.001; chi(2)(1,N = 361) = 6.73, P = .009). In addition, having 1 (z = 2.69; P = .007) and 2 (z = 2.22; P = .03) smoking risk genotypes had a positive effect on physical activity. These represented significant between-group effects (chi(2)(1,N = 361) = 6.29, P = .01; chi(2)(1,N = 361) = 3.81, P = .05, respectively). Thus, having 1 or more smoking risk genotypes was related to higher levels of physical activity, which, in turn, was related to lower levels of smoking progression for adolescents participating in at least 1 team sport but not for adolescents with no team sport participation. CONCLUSIONS: This study provides the first evidence of an interaction between environmental influences and specific genes on adolescent smoking and may promote an understanding of important protective relationships in the environment.

Adolescent↗

PubMed2006

How do psychological factors influence adolescent smoking progression? The evidence for indirect effects through tobacco advertising receptivity.

OBJECTIVES: To determine whether novelty seeking and depressive symptoms had mediated or indirect effects on adolescent smoking progression through tobacco advertising receptivity. METHODS: More than 1000 adolescents were monitored from 9th grade to 12th grade and completed annual surveys that measured demographic characteristics, smoking behavior, tobacco advertising receptivity, novelty-seeking personality, depressive symptoms, family and peer smoking, alcohol use, and marijuana use. RESULTS: Latent growth modeling indicated that novelty seeking had a significant indirect effect on smoking progression through baseline tobacco advertising receptivity. For each 1-SD increase in novelty seeking, the odds of being more receptive to tobacco advertising increased by 12% (ie, being in a specific category or higher), which in turn resulted in an 11% increase in the odds of smoking progression from 9th grade to 12th grade. The indirect effect from depressive symptoms to smoking progression did not reach significance. CONCLUSIONS: These findings may inform future research on other factors that influence tobacco advertising receptivity, as well as programs aimed at preventing adolescent smoking initiation and progression.

Adolescent↗

PubMed2005

The impact of self-control indices on peer smoking and adolescent smoking progression.

OBJECTIVE: To determine the direct impact of self-control variables on baseline smoking and smoking progression and determine whether self-control had indirect effects on smoking practices through effects on peer smoking. METHODS: Study participants were 918 adolescents who were followed from 9th through the 12th grade and completed self-report measures of peer smoking, self-control, and cigarette smoking. An exploratory factor analysis (EFA) was conducted to assess the factor structure of a 41-item self-control measure. The EFA indicated a six-factor structure comprising of impulsive control, planning, hostile blaming, attentional disregulation, conscientiousness, and physical aggression. RESULTS: The results of a latent growth model indicated that conscientiousness (OR = 0.81, CI = 0.73-0.90), hostile blaming (OR = 0.89, CI = 0.81-0.99), and physical aggression (OR = 1.16, CI = 1.06-1.27) had direct effects on baseline smoking, whereas planning (OR = 0.90, CI = 0.82-0.99) and impulse control (OR = 1.15, CI = 1.02-1.28) had indirect effects on adolescent smoking at baseline through baseline peer smoking. There were no significant direct or indirect effects of the self-control indices on smoking progression. There was a direct effect of peer smoking progression (number of peers who smoked) on adolescent smoking progression, such that increases in the number of peers who smoked across time increased the odds that an adolescent would progress to a higher level of smoking. CONCLUSIONS: Youth smoking prevention and intervention program outcomes may potentially improve by addressing self-control behaviors as they appear to have direct effects on smoking and indirect effects through peers who smoke.

Adolescent↗

PubMed2005

Effects of different nicotine replacement therapies on postcessation psychological responses.

Transdermal nicotine patch (TN) and nicotine nasal spray (NS) are both efficacious forms of smoking cessation treatment, but have different pharmacokinetic properties and modes of action. To understand better psychological responses to treatment, we investigated the effects of TN versus NS on positive affect, negative affect, and withdrawal symptoms during treatment. Participants were randomly assigned to receive TN (n=172) or NS (n=163) plus seven sessions of behavioral counseling, and completed self-report questionnaires at pretreatment and during treatment. TN participants, but not NS participants, reported significant increases in positive affect during treatment. Increases in negative affect and withdrawal were observed, independent of treatment. Only changes in negative affect predicted relapse by the end of the treatment phase. These findings indicate that, although TN may enhance positive affect for smokers in treatment compared with NS, only changes in negative affect predict treatment outcome.

Administration, Cutaneous↗

PubMed2005

Investigation of mechanisms linking media exposure to smoking in high school students.

BACKGROUND: Media exposure has been found to impact adolescent smoking, although the mechanisms of this relationship have not been thoroughly investigated. Drive for thinness and tobacco advertising receptivity, both shown to be associated with smoking, are two potential mediators. METHODS: 967 twelfth grade students completed a self-report survey as part of a longitudinal study of biobehavioral predictors of smoking. Exposure to magazines and television, drive for thinness, tobacco advertisement receptivity, and twelfth grade smoking level were the primary variables of interest. Effects of gender, race, BMI, smoking exposure, and perceived physical appearance were controlled for in the model. RESULTS: Exposure to fashion, entertainment, and gossip magazines had indirect effects on smoking via drive for thinness and tobacco advertisement receptivity. There was a direct effect of health, fitness, and sports magazine reading on smoking. Television watching had no significant effects on smoking. CONCLUSIONS: Adolescents who read fashion, entertainment, and gossip magazines may be more likely to smoke, in part, because of a higher drive for thinness and greater receptivity to cigarette advertisements. Conversely, adolescents reading Health and Fitness magazines may be less likely to smoke. Drive for thinness and tobacco advertising receptivity are thus potential targets for adolescent smoking intervention.

Adolescent↗

PubMed2005

Recurrent event analysis of lapse and recovery in a smoking cessation clinical trial using bupropion.

We report a reanalysis of data from a prior study describing the event history of quitting smoking aided by bupropion, using recurrent-event models to determine the effect of the drug on occurrence of lapses and recoveries from lapse (resumption of abstinence). Data were collected on 1,070 subjects across two similar double-blind randomized clinical trials of bupropion versus placebo and fitted with separate Cox regression models for lapse and recovery. Analyses were split using discrete time-varying covariates between the treatment (weeks 1-10) and follow-up phases (end of treatment to 12 months). Bupropion was associated with slower lapse during treatment for both sexes, and being female was associated with faster lapse across both phases. Drug did not affect time to recovery for males but was associated with faster recovery among females, allowing women to recover as quickly as men. High levels of nicotine dependence did not affect time to lapse but were associated with slower recovery from lapse across treatment and follow-up phases. During the treatment phase, higher levels of baseline depression symptoms had no effect on time to lapse but were associated with slower recovery from lapse. Results highlight the asymmetry in factors preventing lapse versus promoting recovery. Specifically, dependence, depression symptoms, and a sex x drug interaction were found to affect recovery but not lapse. Further research disentangling lapse and recovery events from summary abstinence measures is needed to help us develop interventions that take advantage of bupropion at its best and that compensate where it is weak.

Adult↗

PubMed2005

Physical activity, global physical self-concept, and adolescent smoking.

BACKGROUND: Previous research supports a possible protective effect for physical activity against adolescent smoking. However, it is not clear whether the effect of physical activity on smoking is direct (e.g., time spent in physical activity) or indirect through another variable. One such variable is global physical self-concept (GPSC). Briefly, GPSC is a general perception of one's physical self, including appearance and physical activity competence. PURPOSE: This study tested a structural equation model of the relationship between physical activity and smoking, with direct effects from physical activity to smoking and an indirect effect through GPSC. METHODS: Participants were 983 12th graders taking part in a study of the biobehavioral predictors of adolescent smoking adoption. RESULTS: Controlling for covariates of adolescent smoking (e.g., peer smoking, alcohol use) and GPSC (e.g., body mass index, perceived physical appearance), physical activity had an indirect effect on smoking through its effects on GPSC, suggesting that the potential beneficial effects of physical activity on adolescent smoking may depend, in part, on GPSC. CONCLUSIONS: These results suggest that an adolescent's perception of the physical self may be one important factor to consider in youth smoking interventions. Further research is necessary to evaluate the longitudinal relationship between physical activity, GPSC, and smoking.

Adolescent↗

PubMed2004

Individualizing nicotine replacement therapy for the treatment of tobacco dependence: a randomized trial.

BACKGROUND: Despite the well-documented efficacy and different pharmacokinetic and pharmacodynamic properties of different forms of nicotine replacement therapy, empirical data are insufficient to guide practitioners in selecting a particular form of treatment for individual patients with tobacco dependence. OBJECTIVE: To evaluate the comparative efficacy of transdermal nicotine and nicotine nasal spray and identify predictors of treatment outcome. DESIGN: Randomized, open-label clinical trial with a 6-month follow-up period. SETTING: 2 university-based smoking cessation research programs. PARTICIPANTS: 299 treatment-seeking smokers who were followed for 6 months after the target quit date. INTERVENTION: Behavioral group counseling and 8 weeks of therapy with nicotine nasal spray or transdermal nicotine. MEASUREMENTS: Demographic characteristics, smoking history, depression symptoms, and body mass index were measured at baseline. Smoking practices were biochemically verified at the end of treatment and at 6 months after the target quit date. RESULTS: Abstinence rates for the transdermal nicotine and nicotine nasal spray groups were not significantly different at 6-month follow-up (15.0% vs. 12.2%, respectively; P > 0.2). Interactions in abstinence rates for subgroups of smokers were statistically significant (P < 0.05). Smokers who had low to moderate dependence levels, were not obese, and were white achieved higher abstinence rates with transdermal nicotine, whereas smokers who were highly dependent, obese, or members of minority groups achieved higher abstinence rates with nasal spray. LIMITATIONS: The subgroup findings need confirmation in additional large studies before they are routinely applied. CONCLUSIONS: Ethnicity, weight, and level of nicotine dependence may help identify smokers who have greater or lesser abstinence rates with either transdermal or nasal spray nicotine.

Administration, Cutaneous↗

PubMed2004

Construct validity analysis of the early smoking experience questionnaire for adolescents.

Analysis was undertaken to assess the construct validity of a measure of early smoking experience with a sample of adolescent smokers who had ever tried smoking. The results of this study support a two-factor structure of early smoking experience as well as the assertion that initial smoking experience can be characterized by both unpleasant and pleasant sensations. A cross-structure analysis with related and unrelated constructs supports the convergent and discriminant validity of the measure for an adolescent population.

Adolescent↗

PubMed2004

Applying a behavioral economic framework to understanding adolescent smoking.

Adolescents' choice to smoke may depend on substitute reinforcers for smoking, complementary activities to smoking, and individual differences in reinforcer value. The influence of these variables on smoking was determined among 983 adolescents. Substitutes were school involvement, academic performance, physical activity, and sports team participation: complements were peer smoking and substance use; delay discounting assessed individual differences in reinforcer value. Latent growth modeling indicated that substitute reinforcers reduced the odds of smoking progression almost two-fold, complementary reinforcers increased the odds by 1.14. and delay discounting indirectly influenced the odds of smoking progression through complementary reinforcers. Adolescents who smoke may have fewer reinforcers that protect against smoking and more reinforcers that promote smoking. Discounting of future rewards affects smoking through reinforcer type.

Adolescent↗

PubMed2004

Effect of bupropion on depression symptoms in a smoking cessation clinical trial.

Bupropion is an antidepressant shown to be efficacious for smoking cessation. This study examined the short- and long-term effects of bupropion (300 mg/day for 10 weeks) versus placebo on depression symptoms among 497 smokers attempting to quit in a randomized trial of bupropion plus behavioral counseling. Depression symptoms were assessed via the Center for Epidemiological Studies Depression Scale (L. Radloff, 1977) at baseline, end of treatment, and at 6-month follow-up. Baseline nicotine dependence level was assessed with the Fagerström Test for Nicotine Dependence (T. F. Heatherton, L. T. Kozlowski, R. C. Frecker, & K. O. Fagerstrom, 1991). A regression model of depression symptoms demonstrated a significant interaction between nicotine dependence and treatment for the treatment phase and during follow-up. Depression symptoms did not mediate the effects of bupropion on abstinence at either time point. Highly nicotine-dependent smokers who receive bupropion are more likely to experience a decrease in depressive symptoms during active treatment but are also more likely to experience a rebound in depressive symptoms when bupropion is discontinued.

Antidepressive Agents, Second-Generation↗

PubMed2004

Gender differences in smoking cessation in a placebo-controlled trial of bupropion with behavioral counseling.

Among smokers, women may be at greater risk than men for developing smoking-related diseases, perhaps because they have greater difficulty quitting smoking, as suggested by numerous studies. In the present study, we hypothesized that bupropion would reduce this gender disparity among 314 women and 241 men enrolled in a placebo-controlled, randomized trial using behavioral counseling plus 10 weeks of bupropion (300 mg). Prolonged abstinence and biochemically verified point prevalence outcomes were measured at end of treatment (8 weeks after the quit date) and at 6-month follow-up. A logistic regression model of 6-month prolonged abstinence and a Cox regression (survival analysis) model revealed a significant gender by smoking rate by drug interaction and a main effect for marital status. This three-way interaction suggests that bupropion particularly benefited men who smoked more than one pack of cigarettes per day at baseline and, conversely, women who smoked a pack or less. The point prevalence logistic regression model showed no evidence that either gender or smoking rate modified the effect of treatment. These results suggest that bupropion treatment may reduce the gender disparity in prolonged abstinence rates among lighter smokers.

Adult↗

PubMed2004

Do small lapses predict relapse to smoking behavior under bupropion treatment?

Although bupropion is known to be an effective aid to smoking cessation, little is known about its mode of action. In the present study we tested the hypothesis that bupropion reduces the likelihood that a smoking lapse, or slip, leads to a subsequent relapse. This hypothesis was tested in the context of a clinical trial of bupropion as a smoking cessation aid, using Cox regression and representing lapse history as a discrete time-varying covariate. Bupropion treatment reduced the probability of relapse during the treatment phase (hazard ratio, or HR=.421, p< or =.000) but not during the follow-up phase (end of treatment to 6 months, HR=.896, p< or=.67). As anticipated, having small lapses during treatment contributed to or predicted subsequent relapse, both during treatment (HR=2.897, p< or =.000) and during follow-up (HR=2.320, p< or=.008). Although an interaction was found between drug treatment and lapse history in predicting subsequent failure during the treatment phase, the finding suggested that drug slightly increased the effect of lapse on eventual failure during treatment (HR=1.706, p<or=.012). No evidence was found that the effect of this interaction carried forward into follow-up (HR=1.500, p<or=.30). Although the mechanisms of action of bupropion may best be addressed in a human laboratory study, results from this clinical trial suggest that the effectiveness of bupropion treatment is not attributable to reducing the effect of a lapse in predicting relapse.

Adult↗

PubMed2004

Team sport participation and smoking: analysis with general growth mixture modeling.

OBJECTIVE: To assess the likelihood of smoking among adolescents with different patterns of team sport participation, grades 9-11. METHODS: Adolescents (N = 1098) participating in a longitudinal study of the biobehavioral predictors of smoking adoption completed items assessing various health-related behaviors, including team sport participation and smoking practices. General growth mixture modeling (GGMM) was used to analyze the data. RESULTS: Four patterns of team sport participation were found. Adolescents with decreasing or erratic participation were nearly three times more likely than adolescents with high participation to be current smokers in eleventh grade. Nonwhites were at particular risk for decreasing and erratic patterns of participation, and later smoking. Females were at high risk for low team participation. CONCLUSION: Results suggest that multiple patterns of team sport participation can be identified with GGMM and that these patterns may be useful in characterizing individuals at particular risk for future smoking.

Adolescent↗

PubMed2004

Interacting effects of genetic predisposition and depression on adolescent smoking progression.

OBJECTIVE: The goal of the present study was to identify specific genetic associations with smoking progression in adolescents and to determine whether these genetic effects on smoking practices are potentiated by depression symptoms. METHOD: Effects of dopamine transporter (SLC6A3) and dopamine receptor (DRD2) genetic variants on smoking progression were evaluated in a cohort of 615 adolescents, including those who had never smoked, and in a subgroup including only adolescents who had been exposed to nicotine (i.e., smoked at least a puff of a cigarette) (N=292). These adolescents were followed from 9th to 11th grade. Depression symptoms were also assessed. RESULTS: In the model of adolescents with a previous smoking experience, the likelihood of progressing to a higher level of smoking by the 11th grade increased almost twofold with each additional DRD2 A1 allele. The likelihood of smoking progression with each additional A1 allele was more pronounced among adolescents with substantial depression symptoms. The model including never-smokers revealed no significant genetic effects. Neither model revealed effects of SLC6A3. CONCLUSIONS: These results provide the first evidence, to the authors' knowledge, for an association of the DRD2 A1 allele with smoking progression among adolescents. This effect is potentiated by depression symptoms. These effects appear to be specific to adolescents who have had at least some nicotine exposure (i.e., at least a puff of a cigarette).

Adolescent↗

PubMed2004

Using logistic regression to estimate delay-discounting functions.

The monetary choice questionnaire (MCQ) and similar computer tasks ask preference questions in order to ascertain indifference, the perceived equivalence of immediate versus larger delayed rewards. Indifference data are then fitted with a hyperbolic function, summarizing the decline in perceived value with delay time. We present a fitting method that estimates the hyperbolic parameter k directly from survey responses. Binary preferences are modeled as a function of time (X2) and a transformed reward ratio (X1), yielding logistic regression coefficients beta 2 and beta 1. The hyperbolic parameter emerges as k = beta 2/beta 1, where the logistic predicted p = .5 (the definition of indifference). The MCQ was administered to 1,073 adolescents and was scored using both standard and logistic methods. The means for In(k) were similar (standard, -4.53; logistic, -4.51), and the results were highly correlated (rho = .973). Simulated MCQ data showed that k was unbiased, except where beta 1 > or = -1, indicating a vague survey response. Jackknife standard errors provided excellent coverage.

Algorithms↗

PubMed2004

Identifying and characterizing adolescent smoking trajectories.

Our understanding of longitudinal patterns of adolescent smoking development and the determinants of these patterns is limited. The present study evaluated adolescent smoking trajectories and characterized these trajectories with social, psychological, and behavioral factors in a cohort of adolescents assessed annually from grades 9 to 12. Complete data (smoking practices, novelty seeking, academic performance, substance use, peer smoking, physical activity and sports participation, and tobacco ad receptivity) were available on 968 participants; data were analyzed using latent class growth modeling. Four adolescent smoking trajectories emerged: never smokers, experimenters, earlier/faster smoking adopters, and later/slower smoking adopters. Early adopters were characterized by their high novelty seeking personality, depressive symptoms, poorer academic performance, and receptivity to tobacco advertising, as well as their exposure to other smokers, and use of other substances. Later adopters were characterized quite similarly to the early adopters, although they tended to perform better in school and to be more involved in sports. Experimenters also shared many of these same risk characteristics but to a lesser degree. Overall, never smokers were the most conventional in their profile. These data suggest that there is significant heterogeneity in the timing, rate, and intensity of smoking progression. Adolescent smoking prevention and intervention programs will need to consider this heterogeneity and tailor or enhance attention to risk and protective factors depending on the subpopulation.

Adolescent↗