Biochemical, demographic, and self-reported tobacco-related predictors of the acute heart rate response to nicotine in smokers

Associations Between Childhood Trauma and Tobacco Use Outcomes in Adults after Overnight Abstinence

INTRODUCTION

Childhood trauma is known to be associated with nicotine dependence, yet limited smoking outcomes have been examined and few studies have assessed associations between specific trauma subscales and smoking. Additionally, sex differences in trauma-smoking relations are understudied. This study examined associations between childhood trauma and several smoking-related outcomes in adults who smoke after overnight abstinence.

AIMS AND METHODS

People who smoke (N = 205) completed self-report and biochemical assessments evaluating childhood trauma, affect, nicotine dependence, smoking urges, withdrawal, and plasma cortisol and cotinine levels. Smoking outcomes were compared between those with and without a history of moderate to severe childhood trauma among the total sample and by sex.

RESULTS

Relative to those with no to minimal abuse, those with moderate to severe abuse had higher negative affect, withdrawal severity, and plasma cotinine levels. Exploratory analyses revealed that women were more likely than men to have urges to smoke for negative reinforcement and have higher withdrawal severity, but no interactions between abuse group and sex were observed. Examining specific trauma subscales, the moderate to severe emotional abuse group had more severe nicotine dependence, negative affect, and withdrawal compared to the no to minimal group. The moderate to severe sexual abuse group had more severe nicotine dependence and withdrawal compared to the no to minimal group.

CONCLUSIONS

Exposure to childhood trauma is associated with more severe nicotine dependence, negative affect, withdrawal, and higher plasma cotinine levels. Findings also indicate that different types of trauma may differentially affect smoking behaviors.

IMPLICATIONS

This study of adults who smoke finds that childhood trauma history may be a marker for smoking susceptibility and suggests that individuals with experiences of emotional and sexual abuse may require targeted forms of smoking cessation interventions. Moreover, findings suggest that smoking risks may differ for men and women. Findings inform public health interventions intended to reduce cigarette use in individuals with exposure to childhood trauma.

Examining racial differences in smoking outcomes among smokers enrolled in an intravenous nicotine infusion study

INTRODUCTION

Large racial disparities exist in the prevention and treatment of smoking-related diseases, and minoritized populations carry a heavier burden of smoking-related morbidity and mortality. To date, most studies investigating smoking-related illnesses have been conducted in samples in which the majority, or totality, self-identified as White or Caucasian. While Black individuals who smoke tend to have a lower rate of nicotine clearance, in part due to the use of mentholated cigarettes, less is known about how slower clearance affects their acute subjective and physiologic responses in response to either overnight abstinence or subsequent nicotine administration. This study aimed to investigate differences between the experiences of Black and White individuals who smoke across these outcomes after a period of short-term abstinence and after IV nicotine infusion.

METHODS

The study included 206 smokers (N = 103 Black, N = 103 White, by self-report). The study investigated self-report, physiological, and biochemical smoking-related outcomes following confirmed overnight abstinence followed by IV nicotine infusion. The outcome measures were separately analyzed with repeated-measures mixed-models.

RESULTS

Black individuals had lower rates of nicotine clearance and were more likely to smoke mentholated cigarettes than White individuals. Despite these differences, no differences in withdrawal, cravings, or physiological outcomes were observed between the two groups. There were some trends toward differences in subjective experiences, in that an interaction with trend level significance between race and dose was observed for negative subjective drug effects, with White smokers trending towards endorsing higher levels of negative affect after abstinence and nicotine infusion. We also observed that Black individuals trended towards experiencing more negative drug effects in response to initial nicotine delivery than to saline, whereas White individuals had no differences in negative drug effects across saline or nicotine doses.

CONCLUSIONS

Despite slower nicotine clearance, Black participants exhibited withdrawal and urges to smoke as severe as White participants, and did not have blunted physiological responses to overnight abstinence or administration of nicotine, which were contrary to our hypotheses. Our findings suggest minimal differences across races in the acute pharmacologic effects of nicotine. We observed trend-level differences in subjective and affective responses to nicotine. Greater insight into these differences may lead to improved prevention and treatment strategies for smoking-related illnesses for Black individuals who smoke.

The pH of Smokeless Tobacco Determines Nicotine Buccal Absorption: Results of a Randomized Crossover Trial

Nicotine absorption rate influences tobacco products' addictiveness. For smokeless tobacco, nicotine buccal absorption is associated with its free-base form; the pH of smokeless tobacco defines the proportion of free-base (i.e., unprotonated) vs. protonated nicotine. This was the first study to compare nicotine pharmacokinetics (PK) and pharmacodynamics (PD) after the use of commercial smokeless tobacco products that were experimentally manipulated to differ only in pH and percent free-base nicotine. Moist snuff users (N = 40) completed four crossover visits and used a single 2 g portion of Copenhagen Original Long Cut amended to 4 pH levels: 5.0, 7.7, 8.2, and 8.6 (free-base nicotine 0.1, 32, 60, and 79%) for 30 minutes. Nicotine PK and PD were assessed for 4 hours post-use. Nicotine PK substantially depends on its free-base proportion, with more than 4-fold increases in mean plasma nicotine maximum concentration and area under the curve over 240 minutes (3.9 to 16.7 ng/mL; 385 to 1810 ng min/mL, respectively, both P < 0.001) from pH 5.0 to 8.6. The autonomic cardiovascular effects of smokeless tobacco use reflected percent free-base nicotine, with small (albeit significant) systematic increases in heart rate and blood pressure associated with free-base nicotine. Smokeless tobacco product pH and percent free-base nicotine play a major role in the rate and extent of nicotine absorption, determining product PD effects and abuse potential. Research and regulation of smokeless tobacco products should consider both total nicotine content and product pH. Further research may address the impact of modifying pH on the addictiveness of smokeless tobacco and associated use behaviors.

Biological effects of nicotine exposure: A narrative review of the scientific literature

The emergence of new tobacco heating products and electronic nicotine delivery systems (ENDS) is changing the way humans are exposed to nicotine. The purpose of this narrative review is to provide a broad overview of published scientific literature with respect to the effects of nicotine on three key health-related areas: 1) cardiovascular risk, 2) carcinogenesis and 3) reproductive outcomes. These areas are known to be particularly vulnerable to the effects of cigarette smoke, and in addition, nicotine has been hypothesized to play a role in disease pathogenesis. Acute toxicity will also be discussed. The literature to February 2019 suggests that there is no increased cardiovascular risk of nicotine exposure in consumers who have no underlying cardiovascular pathology. There is scientific consensus that nicotine is not a direct or complete carcinogen, however, it remains to be established whether it plays some role in human cancer propagation and metastasis. These cancer progression pathways have been proposed in models in vitro and in transgenic rodent lines in vivo but have not been demonstrated in cases of human cancer. Further studies are needed to determine whether nicotine is linked to decreased fertility in humans. The results from animal studies indicate that nicotine has the potential to act across many mechanisms during fetal development. More studies are needed to address questions regarding nicotine exposure in humans, and this may lead to additional guidance concerning new ENDS entering the market.

Cardiovascular, carcinogenic and reproductive effects of nicotine exposure: A narrative review of the scientific literature

The emergence of new tobacco heating products and electronic nicotine delivery systems (ENDS) is changing the way humans are exposed to nicotine. The purpose of this narrative review is to provide a broad overview of published scientific literature with respect to the effects of nicotine on three key health-related areas: 1) cardiovascular risk, 2) carcinogenesis and 3) reproductive outcomes. These areas are known to be particularly vulnerable to the effects of cigarette smoke, and in addition, nicotine has been hypothesized to play a role in disease pathogenesis. Acute toxicity will also be discussed. The literature to February 2019 suggests that there is no increased cardiovascular risk of nicotine exposure in consumers who have no underlying cardiovascular pathology. There is scientific consensus that nicotine is not a direct or complete carcinogen, however, it remains to be established whether it plays some role in human cancer propagation and metastasis. These cancer progression pathways have been proposed in models in vitro and in transgenic rodent lines in vivo but have not been demonstrated in cases of human cancer. Further studies are needed to determine whether nicotine is linked to decreased fertility in humans. The results from animal studies indicate that nicotine has the potential to act across many mechanisms during fetal development. More studies are needed to address questions regarding nicotine exposure in humans, and this may lead to additional guidance concerning new ENDS entering the market.