Nicotine Addiction: Mechanisms and Consequences

Joint Effects of Lifestyle Habits and Heavy Metals Exposure on Chronic Stress Among U.S. Adults: Insights from NHANES 2017-2018

BACKGROUND

Chronic stress, characterized by sustained activation of physiological stress response systems, is a key risk factor for numerous health conditions. Allostatic load (AL), a biomarker of cumulative physiological stress, offers a quantitative measure of this burden. Lifestyle habits such as alcohol consumption and smoking, alongside environmental exposures to toxic metals like lead, cadmium, and mercury, were individually implicated in increasing AL. However, the combined impact of these lifestyle habits and environmental factors remains underexplored, particularly in populations facing co-occurring exposures. This study aims to investigate the joint effects of lifestyle habits and environmental factors on AL, using data from the NHANES 2017-2018 cycle. By employing linear regression and Bayesian Kernel Machine Regression (BKMR), we identify key predictors and explore interaction effects, providing new insights into how cumulative exposures contribute to chronic stress. Results from BKMR analysis underscore the importance of addressing combined exposures, particularly the synergistic effects of cadmium and alcohol consumption, in managing physiological stress.

METHODS

Descriptive statistics were calculated to summarize the dataset, and multivariate linear regression was performed to assess associations between exposures and AL. BKMR was employed to estimate exposure-response functions and posterior inclusion probabilities (PIPs), focusing on identifying key predictors of AL.

RESULTS

Descriptive analysis indicated that the mean levels of lead, cadmium, and mercury were 1.23 µg/dL, 0.49 µg/dL, and 1.37 µg/L, respectively. The mean allostatic load was 3.57. Linear regression indicated that alcohol consumption was significantly associated with increased AL (β = 0.0933; 95% CI [0.0369, 0.1497]; p = 0.001). Other exposures, including lead (β = -0.1056; 95% CI [-0.2518 to 0.0408]; p = 0.157), cadmium (β = -0.0001, 95% CI [-0.2037 to 0.2036], p = 0.999), mercury (β = -0.0149; 95% CI [-0.1175 to 0.0877]; p = 0.773), and smoking (β = 0.0129; 95% CI [-0.0086 to 0.0345]; p = 0.508), were not significant. BKMR analysis confirmed alcohol's strong importance for AL, with a PIP of 0.9996, and highlighted a non-linear effect of cadmium (PIP = 0.7526). The interaction between alcohol and cadmium showed a stronger effect on AL at higher exposure levels. In contrast, lead, mercury, and smoking demonstrated minimal effects on AL.

CONCLUSIONS

Alcohol consumption and cadmium exposure were identified as key contributors to increased allostatic load, while other exposures showed no significant associations. These findings emphasize the importance of addressing lifestyle habits and environmental factors in managing physiological stress.

Relationship between electronic cigarette use, dual smoking habits, and psychological distress among youth in Northern Thailand: A cross-sectional study

INTRODUCTION

Amidst the escalating trend of electronic cigarette (e-cigarette) use and dual smoking habits among youth, understanding their potential impact on psychological well-being is imperative. Limited research has explored this relationship, particularly among youth in settings where e-cigarettes are banned. This study investigates the relationship between current e-cigarette and traditional cigarette use patterns and the presence of depression and anxiety symptoms among youth in Thailand.

METHODS

Using a cross-sectional survey encompassing 3424 individuals aged 15-24 years in Northern Thailand from December 2021 to September 2022, we accessed cigarette and e-cigarette usage over the past 30 days alongside depression and anxiety symptoms over the past two weeks. Multivariable logistic regression was employed to analyze the association of these variables, adjusting for sociodemographic factors.

RESULTS

Among the surveyed youths, 10.8% reported cigarette use, 6.2% utilized e-cigarettes, and 3.3% were dual users within the past 30 days. Regarding mental health, 33.96% exhibited moderate-severe to severe depression, while 52.54% experienced anxiety at similar levels. After adjusting for covariates, both current e-cigarette users and dual users exhibited heightened depression symptoms (AOR=1.80; 95% CI: 1.30-2.51, and AOR=2.30; 95% CI: 1.49-3.55, respectively) and only e-cigarette use had increased odds of increased anxiety levels (AOR=1.70; 95% CI: 1.24-2.32) compared to non-users. Notably, current cigarette smokers demonstrated no association with depression but had decreased odds of higher levels of anxiety compared to non-users (AOR=0.73; 95% CI: 0.55-0.96).

CONCLUSIONS

A substantial number of Thai youths are using e-cigarettes and experiencing psychological distress. E-cigarette use is associated with heightened levels of depression and anxiety, whereas cigarette smoking is not associated with depression but is likely to be associated with an increased reporting of anxiety. These contradictory findings highlight the need for comprehensive investigations, especially when e-cigarettes are prohibited.

Validation of the Glover-Nilsson Smoking Behavioral Questionnaire (GN-SBQ) to Evaluate Nicotine Dependence in Spanish Clinical Settings

An assessment of the different aspects of tobacco addiction is central to adapting interventions to the profiles and needs of smokers. The Glover−Nilsson Smoking Behavioral Questionnaire (GN-SBQ) is one of the few and most used scales to evaluate the behavioral aspects of tobacco addiction. However, few studies involve the validation of the GN-SBQ in clinical settings. Thus, this study aimed to analyze the psychometric properties of the GN-SBQ in a sample of Spanish smokers. A total of 341 smokers attending clinical services in Spain participated in this cross-sectional study. Measures included the psychological factors related to tobacco addiction, assessed with the GN-SBQ, the physical factors of nicotine addiction, withdrawal symptoms, smoking-related variables, and alcohol use. Data analysis included descriptive statistics, internal consistency coefficients, confirmatory factor analyses, Spearman correlations, and the Kruskal−Wallis test. The GN-SBQ showed adequate reliability (α = 0.76 and ω = 0.76) and a unidimensional structure. GN-SBQ scores also provided evidence of convergent and concurrent validity. GN-SBQ scores significantly correlated with the physical symptoms of addiction, age, number of cigarettes, and withdrawal symptoms. The results of discriminant validity were also adequate, as no correlation was observed between GN-SBQ scores and CO levels or alcohol use. Significant differences were found between all levels of psychological addiction based on the GN-SBQ scores regarding physical nicotine addiction, withdrawal symptoms, and age. Thus, this questionnaire is a reliable and valid instrument to assess the psychological aspects of tobacco addiction in smokers in clinical settings. The short length of the GN-SBQ proves advantageous for its use in time-limited assessments, which are common in public health services.

The social gradient in smoking: individual behaviour, norms and nicotine dependence in the later stages of the cigarette epidemic

The cigarette epidemic tends to develop in a similar pattern across diverse populations in different parts of the world. First, the prevalence of smoking increases, then it plateaus and finally it declines. The decline in smoking prevalence tends to be more pronounced in higher social strata. The later stages of the cigarette epidemic are characterized by emerging and persisting socioeconomic gradients in smoking. Due to its detrimental health consequences, smoking has been the subject of extensive research in a broad range of academic disciplines. I draw on literature from both the social and medical sciences in order to develop a model in which physiological nicotine dependence, individual smoking behaviour and norms surrounding smoking in the immediate social environment are related through reflexive processes. I argue that the emergence and persistence of social gradients in smoking at the later stages of the cigarette epidemic can be attributed to a combination of the pharmacological properties of nicotine, network homophily and the unequal distribution of material and non-material resources across social strata.

Understanding Nicotine Dependence and Addiction Among Young Adults Who Smoke Cigarillos: A Qualitative Study

Introduction

Cigarillo use is increasing, particularly among young adults. Nicotine dependence (ND) is important for understanding smoking behavior and cessation, but the development of measures of ND has focused almost exclusively on cigarette smokers. We examined smoking patterns, preferences, and beliefs of cigarillo users to better understand their experience of addiction and expression of ND symptoms.

Methods

Using purposive sampling, we conducted in-depth interviews between June 2015 and January 2016 with 30 young adults aged 18-28 who reported smoking ≥1 cigarillo per week. Interviews were based on a semi-structured guide designed to capture participants' smoking levels and patterns as well as their experiences of smoking and addiction. Interviews were audio-recorded and transcribed. Analysis was guided by a phenomenological approach designed to identify emergent themes.

Results

Participants had a mean age of 23, with a majority being female (56%) and African American (80%). The median number of cigarillos smoked per week was 20; 70% also smoked cigarettes, and 43% also smoked marijuana blunts. Our analysis highlighted the complexity of measuring cigarillo use due to product manipulation, sharing, and multiple product use. Participants expressed a preference for smoking in a social group where cigarillos were shared, and not smoking an entire cigarillo at once when alone. Most cigarillo users did not consider themselves to be addicted.

Conclusions

Cigarillo users express unique smoking practices and beliefs that signify the need for a more product-inclusive measure of ND, and can inform the development of tobacco cessation interventions tailored to cigarillo users.

Implications

The increasing use of cigarillos among young adults has significant public health consequences. Addressing this issue requires accurate measurement and effective treatment of dependence on cigarillo products. The results of this study directly inform the development of a revised measure of ND, and can contribute to the efficacy of cessation interventions for cigarillo users.

Development of the PROMIS nicotine dependence item banks

INTRODUCTION

Nicotine dependence is a core construct important for understanding cigarette smoking and smoking cessation behavior. This article describes analyses conducted to develop and evaluate item banks for assessing nicotine dependence among daily and nondaily smokers.

METHODS

Using data from a sample of daily (N = 4,201) and nondaily (N =1,183) smokers, we conducted a series of item factor analyses, item response theory analyses, and differential item functioning analyses (according to gender, age, and race/ethnicity) to arrive at a unidimensional set of nicotine dependence items for daily and nondaily smokers. We also evaluated performance of short forms (SFs) and computer adaptive tests (CATs) to efficiently assess dependence.

RESULTS

A total of 32 items were included in the Nicotine Dependence item banks; 22 items are common across daily and nondaily smokers, 5 are unique to daily smokers, and 5 are unique to nondaily smokers. For both daily and nondaily smokers, the Nicotine Dependence item banks are strongly unidimensional, highly reliable (reliability = 0.97 and 0.97, respectively), and perform similarly across gender, age, and race/ethnicity groups. SFs common to daily and nondaily smokers consist of 8 and 4 items (reliability = 0.91 and 0.81, respectively). Results from simulated CATs showed that dependence can be assessed with very good precision for most respondents using fewer than 6 items adaptively selected from the item banks.

CONCLUSIONS

Nicotine dependence on cigarettes can be assessed on the basis of these item banks via one of the SFs, by using CATs, or through a tailored set of items selected for a specific research purpose.

Developmental consequences of fetal exposure to drugs: what we know and what we still must learn

Most drugs of abuse easily cross the placenta and can affect fetal brain development. In utero exposures to drugs thus can have long-lasting implications for brain structure and function. These effects on the developing nervous system, before homeostatic regulatory mechanisms are properly calibrated, often differ from their effects on mature systems. In this review, we describe current knowledge on how alcohol, nicotine, cocaine, amphetamine, Ecstasy, and opiates (among other drugs) produce alterations in neurodevelopmental trajectory. We focus both on animal models and available clinical and imaging data from cross-sectional and longitudinal human studies. Early studies of fetal exposures focused on classic teratological methods that are insufficient for revealing more subtle effects that are nevertheless very behaviorally relevant. Modern mechanistic approaches have informed us greatly as to how to potentially ameliorate the induced deficits in brain formation and function, but conclude that better delineation of sensitive periods, dose-response relationships, and long-term longitudinal studies assessing future risk of offspring to exhibit learning disabilities, mental health disorders, and limited neural adaptations are crucial to limit the societal impact of these exposures.