Nicotine dependence: health consequences, smoking cessation therapies, and pharmacotherapy

Smoking during pregnancy and harm reduction in birth weight: a cross-sectional study

Background

Different studies have shown the advantages of abstinence from cigarette smoking during pregnancy to promote full fetal development. Given that pregnant women do not always abstain from smoking, this study aimed to analyze the effect of different intensities of smoking on birth weight of the newborn.

Methods

A cross-sectional study was adopted to explore smoking in a population of pregnant women from a medium-sized city in São Paulo state, Brazil, who gave birth between January and June of 2012. Data were collected from maternal and pediatric medical files and, where data were absent, they were collected by interview during hospitalization for delivery. For data analysis, the effect of potential confounding variables on newborn birth weight was estimated using a gamma response model. The effect of the identified confounding variables was also estimated by means of a gamma response regression model.

Results

The prevalence of smoking during pregnancy was 13.4% in the study population. In full-term infants, birth weight decreased as the category of cigarette number per day increased, with a significant weight reduction as of the category 6 to 10 cigarettes per day. Compared with infants born to non smoking mothers, mean birth weight was 320 g lower in infants whose mothers smoked 6 to 10 cigarettes per day and 435 g lower in infants whose mothers smoked 11 to 40 cigarettes per day during pregnancy.

Conclusions

Based on the study results and the principle of harm reduction, if a pregnant woman is unable to quit smoking, she should be encouraged to reduce consumption to less than six cigarettes per day.

The natural history of substance use disorders

PURPOSE OF REVIEW

Illicit drugs, alcohol, and tobacco use disorders contribute substantially to the global burden of disease. Knowledge about the major elements of the natural history of substance use disorders (incidence, remission, persistence, and relapse) is crucial to a broader understanding of the course and outcomes of substance use disorders.

RECENT FINDINGS

Prospective cohort studies in nonclinical samples indicate that externalizing psychopathology in earlier life, including early disordered substance use, delinquency, and personality disorders, are related to substance use disorders later in life and chronic course. Externalizing psychopathology may be initiated by early adverse experiences, for example, childhood maltreatment and stressful life events. After controlling for confounders, 'age at first use' as a causal factor for alcohol use disorder later in life and the 'drug substitution' hypothesis are not supported in general population data.

SUMMARY

Future research should focus on elaborating the causal framework that leads to the development and persistence of severe substance use disorders, with an emphasis on identifying modifiable factors for intervention by policy makers or health professionals. More research is needed on the natural history of substance use disorders in low-income and middle-income countries.

Childhood maltreatment, personality disorders and 3-year persistence of adult alcohol and nicotine dependence in a national sample

BACKGROUND AND AIMS

Persistent cases of alcohol and nicotine dependence are associated with considerable morbidity and mortality, and are predicted by childhood maltreatment and personality disorders. Our aim was to test whether personality disorders (individually or conjointly) mediate the relationship between childhood maltreatment and the persistence of dependence.

DESIGN

Personality disorders, modeled dimensionally, were tested as mediators of the relationship between childhood maltreatment and the 3-year persistence of alcohol and nicotine dependence in participants in the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) who had current alcohol and nicotine dependence in their baseline interview. Individual personality disorders were assessed in separate models. Then, those that were significant were examined jointly in multiple mediator models to determine their total and unique effects.

SETTING

A large, nationally representative US survey.

PARTICIPANTS

Participants ≥ 18 years who completed baseline and 3-year follow-up NESARC interviews who had baseline alcohol dependence (n = 1172; 68% male) or nicotine dependence (n = 4017; 52.9% male).

MEASUREMENTS

Alcohol Use Disorder and Associated Disabilities Interview Schedule (AUDADIS-IV) measures of childhood maltreatment, personality disorders and alcohol/nicotine dependence.

FINDINGS

Individual models indicated that many personality disorders mediated the relationship between childhood maltreatment and the 3-year persistence of alcohol and nicotine dependence (each explaining 6-46% of the total effect, Ps < 0.05). In multiple mediator models, borderline and antisocial symptoms remained significant mediators, each explaining 20-37% of the total effect (Ps < 0.01).

CONCLUSIONS

Personality disorder symptoms (especially borderline and antisocial) help explain the association between childhood maltreatment and persistent alcohol and nicotine dependence.

Genetic similarities between tobacco use disorder and related comorbidities: an exploratory study

Background

Tobacco use disorder (TUD), defined as the use of tobacco to the detriment of a person’s health or social functioning, is associated with various disorders. We hypothesized that mutual variation in genes may partly explain this link. The aims of this study were to make a non-exhaustive inventory of the disorders using (partially) the same genetic pathways as TUD, and to describe the genetic similarities between TUD and the selected disorders.

Methods

We developed a 3 stage approach: (i) selection of genes influencing TUD using Gene2Mesh and Ingenuity Pathway Analysis (IPA), (ii) selection of disorders associated with the selected genes using IPA and (iii) genetic similarities between disorders associated with TUD using Jaccard distance and cluster analyses.

Results

Fourteen disorders and thirty-two genes met our inclusion criteria. The Jaccard distance between pairs of disorders ranged from 0.00 (e.g. oesophageal cancer and malignant hypertension) to 0.45 (e.g. bladder cancer and addiction). A lower number in the Jaccard distance indicates a higher similarity between the two disorders. Two main clusters of genetically similar disorders were observed, one including coexisting disorders (e.g. addiction and alcoholism) and the other one with the side-effects of smoking (e.g. gastric cancer and malignant hypertension).

Conclusions

This exploratory study partly explains the potential genetic components linking TUD to other disorders. Two principle clusters of disorders were observed (i) coexisting disorders of TUD and (ii) side-effects of TUD disorders. A further deepening of this observation in a real life study should allow strengthening this hypothesis.

The risk for persistent adult alcohol and nicotine dependence: the role of childhood maltreatment

BACKGROUND AND AIMS

Alcohol and nicotine dependence are associated with considerable morbidity and mortality, especially when cases are persistent. The risk for alcohol and nicotine dependence is increased by childhood maltreatment. However, the influence of childhood maltreatment on dependence course is unknown, and is evaluated in the current study.

DESIGN

Physical, sexual and emotional abuse, and physical and emotional neglect, were evaluated as predictors of persistent alcohol and nicotine dependence over 3 years of follow-up, with and without control for other childhood adversities.

SETTING

National Epidemiologic Survey on Alcohol and Related Conditions (NESARC).

PARTICIPANTS

NESARC participants completing baseline and follow-up who met criteria at baseline for past-year alcohol dependence (n = 1172) and nicotine dependence (n = 4017).

MEASUREMENTS

Alcohol Use Disorder and Associated Disabilities Interview Schedule (AUDADIS) measures of alcohol/nicotine dependence, childhood maltreatment and other adverse childhood experiences (e.g. parental divorce).

FINDINGS

Controlling for demographics only, physical, sexual and emotional abuse and physical neglect predicted 3-year persistence of alcohol dependence [adjusted odds ratio (AOR) = 1.50-2.99; 95% CI = 1.04-4.68] and nicotine dependence (AOR = 1.37-1.74; 95% CI = 1.13-2.11). With other childhood adversities also controlled, maltreatment types remained predictive for alcohol persistence (AOR = 1.53-3.02; 95% CI = 1.07-4.71) and nicotine persistence (AOR = 1.35-1.72; 95% CI = 1.11-2.09). Further, a greater number of maltreatment types incrementally influenced persistence risk (AOR = 1.19-1.36; 95% CI = 1.11-1.56).

CONCLUSIONS

A history of childhood maltreatment predicts persistent adult alcohol and nicotine dependence. This association, robust to control for other childhood adversities, suggests that maltreatment (rather than a generally difficult childhood) affects the course of dependence.

General mechanisms of nicotine-induced fibrogenesis

Cigarette smoking contributes to the development of cancer, and pathogenesis of other diseases. Many chemicals have been identified in cigarettes that have potent biological properties. Nicotine is especially known for its role in addiction and plays a role in other physiological effects of smoking and tobacco use. Recent studies have provided compelling evidence that, in addition to promoting cancer, nicotine also plays a pathogenic role in systems, such as the lung, kidney, heart, and liver. In many organ systems, nicotine modulates fibrosis by altering the functions of fibroblasts. Understanding the processes modulated by nicotine holds therapeutic potential and may guide future clinical and research decisions. This review discusses the role of nicotine in the general fibrogenic process that governs fibrosis and fibrosis-related diseases, focusing on the cellular mechanisms that have implications in multiple organ systems. Potential research directions for the management of nicotine-induced fibrosis, and potential clinical considerations with regard to nicotine-replacement therapy (NRT) are presented.

Tobacco and metabolic syndrome

Tobacco is a leading contributor to morbidity and mortality globally. Metabolic syndrome is a constellation of abdominal obesity, atherogenic dyslipidemia, raised blood pressure, insulin resistance (with and without glucose intolerance), pro-inflammatory state, and pro-thrombotic state. Tobacco use is associated with various core components of metabolic syndrome. It has been found to play a causal role in various pathways leading on to development this condition, the current article discusses various facets of this association.