Cardiovascular toxicity of nicotine: implications for nicotine replacement therapy

Helping surgical patients quit smoking: why, when, and how

Millions of cigarette smokers undergo elective surgery each year. Efforts to help them quit smoking could improve immediate perioperative outcomes, such as those related to the cardiac and respiratory systems, and the healing of surgical wounds. Perhaps more importantly, the scheduling of elective surgery represents an excellent opportunity for smokers to permanently quit, with great benefit to their long-term health. Although it is difficult for smokers to quit, there are now several interventions of proven benefit that can more than double the chances of success. These include simple physician advice to quit, brief behavioral interventions that can be provided by physicians or other clinicians, and pharmacotherapy with drugs such as nicotine. Although specific strategies tailored for the surgical patient remain to be developed, there are steps that anesthesiologists can implement into their practices now that can help their patients quit smoking.

IMPLICATIONS

The scheduling of elective surgery provides an excellent opportunity for cigarette smokers to quit, given the deleterious effects of smoking on perioperative outcome and the potential for surgery to serve as a "teachable moment" to modify smoking behavior. There are now proven methods to help them do so.

Interventions for preoperative smoking cessation

BACKGROUND

Smokers have a substantially increased risk of intra- and postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence. The preoperative period may be a well chosen time to offer smoking cessation interventions due to increased patient motivation.

OBJECTIVES

The objective of this review was to assess the effect of preoperative smoking intervention on smoking cessation in the postoperative period and longer term. We also set out to determine the effect of smoking cessation on the incidence of postoperative complications.

SEARCH STRATEGY

The specialized register of the Cochrane Tobacco Addiction Group was searched using the free text and keywords (surgery) OR (operation) OR (anaesthesia) or (anesthesia). MEDLINE, EMBASE and CINAHL were also searched, combining tobacco- and surgery-related terms. Most recent search February 2005.

SELECTION CRITERIA

We considered randomized trials which recruited smokers prior to surgery, offered a smoking cessation intervention, and measured abstinence from smoking in the preoperative and postoperative periods. We also considered randomized trials of the effect of smoking cessation on the incidence of intra- and postoperative complications.

DATA COLLECTION AND ANALYSIS

The authors independently assessed studies to determine eligibility. The results were discussed between the authors.

MAIN RESULTS

Four trials met the inclusion criteria. All trials significantly reduced preoperative smoking but the effect sizes were heterogeneous so a pooled effect was not estimated. Only two trials reported the effect of the smoking intervention on wound complications, and the results were heterogeneous, with a significant reduction in wound-related complications, cardiopulmonary complications and the overall risk of any complication in one trial, and no evidence of a difference in complications in the other. The effect on longer term smoking cessation was not significant in either of the two trials with follow up beyond the perioperative period.

AUTHORS' CONCLUSIONS

Preoperative smoking interventions are effective for changing smoking behaviour perioperatively. Direct evidence that reducing or stopping smoking reduces the risk of complications is based on two small trials with differing results. The impact on complications may depend on how long before surgery the smoking behaviour is changed, whether smoking is reduced or stopped completely, and the type of surgery.

Nicotine replacement therapy and ischaemic stroke

A52-year-old right-handed businessman developed sudden onset of non-fluent dysphasia, weakness and sensory disturbance on the right side of his body 3 weeks after starting Nicorette patches (21 mg). He continued to smoke 3–5 cigars a day while on these patches. The patient had a history of depression and excessive alcohol intake.

Examination confirmed an expressive dysphasia with verbal fluency limited to five words beginning with ‘C’ or ‘S’ but with no problems in comprehension, naming or praxis. Rapid alternating movements were impaired on the right and reflexes were brisker on the right side, although both planters were flexor. Cardiovascular and general examination was unremarkable.

Magnetic resonance imaging (MRI) brain scan confirmed a left anterior cerebral artery territory infarct. The following blood tests were normal or unhelpful: erythrocyte sedimentation rate (ESR), C-reactive protein, protein culture and sensitivity, antithrombin, antiphospholipid coagulant, treponemal serology, thyroid screen and autoantibody screen. The patient was found to have mildly raised triglyceride (2.42 mmol/l) and low density lipoprotein (LDL) cholesterol (4.61 mmo/l). Electrocardiogram (ECG), echocardiography and carotid Dopplers were all normal.

Two previous cases of stroke following nicotine patches have been reported by Jackson (1993) and Pierce (1994). In addition, the Medicines and Healthcare products Regulatory Agency (MHRA) have received 12 further cases of cerebrovascular disorders following nicotine replacement (Table 1).

Early atherosclerotic lesions in infancy: role of parental cigarette smoking

Cigarette smoking is associated with an increased incidence of atherosclerotic diseases. The aim of this study was to examine the progression of the pre atherosclerotic lesions previously observed by us in coronary arteries of fetuses of smoker mothers and in infants with smoker parents. We examined the coronary arteries of 34 infants, aged 1-36 months, and the histological and biological [c-fos, proliferating cell nuclear antigen (PCNA), and apoptosis] features of the early atherosclerotic lesions. In 17 infants (50%), at least one parent smoked, generally more than five cigarettes a day. In 18 cases (53%), we observed variable thickening of the coronary walls from pre-atherosclerotic lesions to juvenile atherosclerotic plaques, related to parental smoking habit. This morphological progression of the lesions was accompanied by a sequence of biological changes in the smooth muscle cells of the tunica media. We suggest that the oxidants present in the gas phase of the parental cigarette smoke pass through the endothelium and induce at first the c-fos gene activation and subsequently the PCNA positivity, that is, a proliferative process.

Adverse effects of pharmacological therapy for nicotine addiction in smokers following a smoking cessation program

This multicenter, community-based, prospective, longitudinal study evaluated the safety of nicotine replacement therapy (NRT), bupropion, and combined therapy of NRT and bupropion for smokers seeking to quit, when these therapies were used under real-world conditions following a smoking cessation program. Participants were smokers aged 18 years or older who attended five smoking cessation clinics. Evaluations were made at 15, 30, 60, and 90 days. We investigated the possible existence of adverse effects as well as the severity of each adverse effect and its influence on the treatment course. The study included 904 smokers: 370 received NRT, 413 received bupropion, and 121 received combined therapy. At 15, 30, 60, and 90 days, adverse effects were reported by 43.8%, 33.1%, 22.3%, and 5.7% of subjects, respectively. Adverse effects were significantly more frequent in subjects receiving combined therapy or bupropion alone than in NRT-treated subjects at the 15-, 30-, and 60-day follow-ups. A total of 83 smokers (9.3%) withdrew from treatment and 116 (12.8%) stopped temporarily because of adverse effects. No differences were found in the percentages of discontinuation among the different treatment options. Adverse effects rarely were severe (n=10). Nevertheless, 41 subjects (4.5%) discontinued drug therapy indefinitely and 55 (6.1%) discontinued it temporarily because of mild adverse effects. Pharmacological therapies for smoking cessation are safe as long as they are appropriately prescribed and supervised by clinicians according to clinical practice guidelines. Adverse effects are primarily mild. Nonetheless, mild adverse effects may be perceived by patients as a serious enough problem to cause them to discontinue treatment.

Swedish moist snuff and myocardial infarction among men

BACKGROUND

Previous studies have provided inconsistent results on possible increased risk of cardiovascular disease with the use of smokeless tobacco. The aim of this study was to assess whether long-term use of Swedish moist snuff (widely used among Swedish men) increases the risk of acute myocardial infarction.

METHODS

This case-control study was conducted in 2 Swedish counties. We identified 1760 men, age 45-70 years, who had a myocardial infarction in 1992-1994. We randomly selected male controls from the study base after stratification for age and hospital catchment area. Information about snuff consumption, smoking history, hypertension, and other factors was obtained by mailed questionnaire and medical examination. The participation rate was 77% among cases and 78% among controls, with tobacco use data available for 1432 cases and 1810 controls.

RESULTS

After adjustment for age, hospital catchment area, and smoking, the relative risk of first acute myocardial infarction was 1.1 (95% confidence interval=0.8-1.5) for former snuff users and 1.0 (0.8-1.3) for current snuff users. Analyses limited to either nonfatal or fatal cases did not change the results. Among the controls, the consumption of smokeless tobacco was strongly associated with certain risk factors for myocardial infarction such as smoking, hypertension, and high body mass index.

CONCLUSION

The hypothesis that smokeless tobacco increases the risk for myocardial infarction is not supported in the present study.

Smoking Cessation: Techniques and Potential Benefits

Smokers have a significantly greater risk of complications during and after operations. Cigarette smoke has significant effects on cardiac function, circulation, and respiratory function. Preliminary studies suggest that smoking cessation for a minimum of 6 to 8 weeks before surgery is required to reduce the perioperative and postoperative risks of smoking. Smoking cessation programs that employ advice, support groups, nicotine replacement therapy, or some anti-depressants have been used successfully in many situations and should be used to discourage smoking preoperatively. Further research is needed, however, to clarify the best approach to smoking cessation for surgical patients.

Nicotine replacement therapy and cardiovascular disease

Smoking is a well-established and important risk factor for cardiovascular disease. Cessation of smoking clearly decreases the chances of a first or subsequent cardiovascular event. Nicotine replacement therapy (NRT) is a proven adJunctive therapy to increase the probability of quitting smoking. Anecdotal reports of adverse events in patients using NRT have led some to question its safety. Is nicotine, whether in tobacco products or in NRT, the cause of the cardiovascular consequences associated with tobacco use? Is using NRT to assist with smoking cessation safer than smoking? Should health care professionals avoid recommending NRT for patients with established cardiovascular disease? This article summarizes the mechanisms of harm associated with smoking and reviews the safety of NRT in both the general population and the population with cardiovascular disease. Recommendations for NRT use are offered.

Smoking cessation in patients with coronary artery disease

BACKGROUND

Smoking cessation is an important factor in the primary and secondary prevention of cardiac events. Although multiple clinical trials have examined the efficacy of various smoking cessation aids, a systematic review of the efficacy and safety of smoking cessation aids has not been done.

METHODS

This paper reviews the effects of smoking on coronary artery disease. In addition, we identify randomized controlled trials examining the efficacy and safety of smoking cessation aids from the years 1970 to 2004. We then pooled the trial results for 6- and 12-month rates of continuous smoking abstinence.

RESULTS

The 4 principal mechanisms of cardiovascular damage caused by cigarette smoking are induction of a hypercoagulable state, reduction of oxygen delivery because of carbon monoxide, coronary vasoconstriction, and nicotine-induced hemodynamic effects. Our review of clinical trials suggests that each smoking cessation aid improved continuous smoking abstinence rates at both 6 and 12 months compared with placebo. The 12-month abstinence rates for the active versus placebo treatments were the following: nicotine patch 11.1% versus 5.5%, nicotine gum 27.3% versus 16.5%, nicotine inhaler 16.9% versus 9.1%, bupropion 18.5% versus 6.6%, and behavioral therapy 20.0% versus 13.9%.

CONCLUSIONS

Several smoking-related mechanisms are responsible for the development of atherosclerosis and the induction of cardiac events. Smoking cessation aids effect a modest increase in smoking abstinence at 12 months compared with placebo. In spite the apparent success of cessation aids, smoking relapse rates are quite high.

Influence of menstrual cycle on cytochrome P450 2A6 activity and cardiovascular effects of nicotine

BACKGROUND AND OBJECTIVES

The phase of the menstrual cycle has been reported to affect frequency of smoking, withdrawal symptoms, and the likelihood of smoking cessation in women. Cytochrome P450 (CYP) 2A6 is primarily responsible for the metabolism of nicotine. Our objective was to evaluate the effect of the phase of the menstrual cycle on the activity of CYP2A6 and the cardiovascular effects of nicotine.

METHOD

Eleven healthy, nonsmoking women received a 30-minute combined infusion of deuterium-labeled nicotine and cotinine (0.5 microg . kg(-1) . min(-1) of each compound) during the midfollicular and midluteal phases of the menstrual cycle. Nicotine and cotinine pharmacokinetic parameters and plasma adrenocorticotropic hormone (ACTH), epinephrine, and norepinephrine responses were measured over time.

RESULTS

There were no biologically or statistically significant differences in the comparison of menstrual cycle phases with regard to the pharmacokinetics of nicotine and cotinine. Nicotine clearance was 1000 +/- 315 mL/min and 1047 +/- 271 mL/min in the follicular and luteal phases, respectively (geometric mean ratio, 1.06; 90% confidence interval, 0.87-1.29). Cotinine clearance was 44 +/- 20 mL/min and 55 +/- 42 mL/min in the follicular and luteal phases, respectively (geometric mean ratio, 1.13; 90% confidence interval, 0.90-1.41). Nicotine infusion increased blood pressure, heart rate, and epinephrine concentrations. There were no differences in catecholamine, ACTH, or hemodynamic responses to nicotine infusion between menstrual cycle phases, although norepinephrine concentrations were constantly higher in the luteal phase compared with the follicular phase.

CONCLUSIONS

CYP2A6 activity is not affected by menstrual cycle phase, and it is unlikely that menstrual cycle-related smoking habits of women are determined by changes in nicotine pharmacokinetics. The effects of nicotine on plasma ACTH and catecholamine levels and hemodynamic parameters are not altered by menstrual cycle phase in healthy, nonsmoking women.

Preoperative smoking cessation: the role of the primary care provider

Millions of cigarette smokers require surgery each year. Those who quit smoking may reduce their risk of respiratory, cardiovascular, and wound-related complications. Scheduling of surgery may present a unique opportunity to help smokers quit permanently. Primary care providers can play an important role in helping their patients scheduled for surgery quit smoking before their operation and maintain their abstinence after surgery. To do so effectively, physicians need to understand (1) the consequences of smoking in the perioperative period and how quitting can mitigate these problems, (2) how surgery can serve as a "teachable moment" to aid in smoking cessation, and (3) specific techniques that can be used to help their patients quit smoking, including brief counseling and pharmacotherapy.

Receptor-mediated tobacco toxicity: regulation of gene expression through alpha3beta2 nicotinic receptor in oral epithelial cells

Tobacco is a known cause of oral disease but the mechanism remains elusive. Nicotine (Nic) is a likely culprit of pathobiological effects because it displaces the local cytotransmitter acetylcholine from the nicotinic receptors (nAChRs) expressed by oral keratinocytes (KCs). To gain a mechanistic insight into tobacco-induced morbidity in the oral cavity, we studied effects of exposures to environmental tobacco smoke (ETS) versus equivalent concentration of pure Nic on human and murine KCs. Both ETS and Nic up-regulated expression of cell cycle and apoptosis regulators, differentiation marker filaggrin, and signal transduction factors at both the mRNA and protein levels. These changes could be abolished in cultured human oral KCs transfected with anti-alpha3 small interfering RNA or treated with the alpha3beta2-preferring antagonist alpha-conotoxin MII. Functional inactivation of alpha3-mediated signaling in alpha3-/- mutant KCs prevented most of the ETS/Nic-dependent changes in gene expression. To determine relevance of the in vitro findings to the in vivo situation, we studied gene expression in oral mucosa of neonatal alpha3+/+ and alpha3-/- littermates delivered by heterozygous mice soon after their exposures to ETS or equivalent concentration of pure Nic in drinking water. In addition to reverse transcriptase-polymerase chain reaction and Western blot, the ETS/Nic-dependent alterations in gene expression were also detected by semiquantitative immunofluorescence assay directly in KCs comprising murine oral mucosa. Only wild-type mice consistently developed significant (P < 0.05) changes in the gene expression. These results identified alpha3beta2 nAChR as a major receptor mediating effects of tobacco products on KC gene expression. Real-time polymerase chain reaction demonstrated that in all three model systems the common genes targeted by alpha3beta2-mediated ETS/Nic toxicity were p21, Bcl-2, NF-kappaB, and STAT-1. The expression of the nAChR subunits alpha5 and beta2 and the muscarinic receptor subtypes M(2) and M(3) was also altered. This novel mechanism offers innovative solutions to ameliorate the tobacco-related cell damage and intercede in disease pathways, and may shed light on general mechanisms regulating and driving tobacco-related morbidity in human cells.

Life-style Modification in Peripheral Arterial Disease

OBJECTIVE

To review the published evidence supporting the use of life-style modification in peripheral arterial disease (PAD).

DESIGN

A systematic search of the medical literature was performed for relevant studies.

MATERIALS

The publications obtained were then searched for randomised clinical trials which reported end-points of mortality or major cardiovascular event rates with various life-style modifications.

RESULTS

Only one randomised controlled trial was found reporting relevant end-points. Other trials were of other end-points such as walking distance or biochemical markers.

CONCLUSIONS

There is a lack of randomised controlled data proving the benefit of life-style modification in improving mortality and reducing cardiovascular events in patients with PAD. Despite this there is sufficient evidence to recommend some life-style modification as part of the overall approach to risk reduction in these patients. There is compelling evidence to support smoking cessation, increased exercise and improved diet.

A nicotine delivery device without the nicotine? Tobacco industry development of low nicotine cigarettes

BACKGROUND

Defining harm reduction and regulating potentially reduced exposure products (PREPs), including low nicotine products, are key issues in tobacco control policy. The US Congress has been considering legislation authorising the Food and Drug Administration (FDA) to regulate tobacco products.

OBJECTIVE

To investigate tobacco industry perceptions, interests, motivations, and knowledge regarding the marketability of low nicotine tobacco products.

METHODS

Qualitative analysis of internal tobacco industry documents identified in the Legacy Tobacco Documents Library between February 2002 and June 2004. Search terms included low-, no-, reduced-nicotine; denicotinization; low-, reduced- alkaloids; Next; de-nic; and key names of people, organisations, projects, and their common abbreviations and acronyms.

RESULTS

The tobacco industry has made repeated efforts to develop low nicotine cigarettes. Reasons for doing so include consumer appeal and economic importance in a highly competitive cigarette market for "healthier" products. The industry considered the development of a new "denic" market segment a critical challenge.

CONCLUSIONS

The tobacco industry exploits consumer misunderstanding of the health effects of nicotine in development and marketing efforts. The industry has risked the development of a less addictive product to expand the market reach of tobacco products based on perceived health benefits and appeal to quitters.

Down-regulating effect of nicotine on connexin43 gap junctions in human umbilical vein endothelial cells is attenuated by statins

We investigated the effect of nicotine on connexin43 (Cx43) expression and gap-junctional communication in human umbilical vein endothelial cells (HUVEC). We also evaluated whether the effect requires activation of acetyl choline receptors sensitive to nicotine (nAChRs) and is altered by statins. The results showed that expression of Cx43 protein is reduced by nicotine in a dose-dependent manner (6 x 10(-4) M nicotine vs control, 33% reduction, p < 0.01), though Cx43 mRNA is up-regulated (6 x 10(-4) M nicotine vs control, 36% increase, p < 0.01). Concomitantly, the communication function, determined by fluorescence recovery after photobleaching, is decreased (6 x 10(-4) M nicotine vs control, 38% reduction, p < 0.05). Such a down-regulation of Cx43 gap junctions by nicotine disappears in the presence of the nAChRs antagonist, dihydro-beta-erythroidine, and protease inhibitors leupeptin plus N-acetyl-Leu-Leu-Norleu-al (ALLN). Similarly, the effect of nicotine is attenuated by statins, including fluvastatin, lovastatin, pravastatin, and simvastatin, even at the presence of mevalonate. We concluded that i) nicotine down-regulates Cx43 expression and gap-junctional communication in HUVEC via post-transcriptional modification, which involves enhancement of Cx43 proteolysis; ii) the effect of nicotine is mediated via activation of nAChRs; and iii) the effect of nicotine is attenuated by statins through mechanisms outside the hypolipidemic pathway.

Pharmacotherapy of tobacco dependence

Smoking cessation activities and support for its implementation should be integrated into the health care system. The outcome of smoking cessation has improved with the availability of proper behavior approaches and medications. Incorporating these guidelines into daily clinical practice ensures that health care providers provide the opportunity for patients to quit smoking. The best hope of improved treatment comes from combining existing and new pharmacotherapies with effective behavioral therapy.

Alpha-7 nicotinic receptor agonists: potential new candidates for the treatment of schizophrenia

RATIONALE AND OBJECTIVE

Auditory sensory gating, a biological measurement of the ability to suppress the evoked response to the second of two auditory stimuli, is diminished in people with schizophrenia. Deficits in sensory gating are associated with attentional impairment, and may contribute to cognitive symptoms and perceptual disturbances. This inhibitory process, which involves the alpha(7) nicotinic receptor mediated release of gamma-aminobutyric acid (GABA) by hippocampal interneurons, represents a potential new target for therapeutic intervention in schizophrenia.

METHOD

This paper will review several lines of evidence implicating the nicotinic-cholinergic, and specifically, the alpha(7) nicotinic receptor system in the pathology of schizophrenia and the evidence that alpha(7) nicotinic receptor agonists may ameliorate some of these deficits.

RESULTS

Impaired auditory sensory gating has been linked to the alpha(7) nicotinic receptor gene on the chromosome 15q14 locus. Single nucleotide polymorphisms of the promoter region of this gene are more frequent in people with schizophrenia. Although nicotine can acutely reverse diminished auditory sensory gating in people with schizophrenia, this effect is lost on a chronic basis due to receptor desensitization. Clozapine is able to reverse auditory sensory gating impairment, probably through an alpha(7) nicotinic receptor mechanism, in both humans and animal models with repeated dosing. The alpha(7) nicotinic agonist 3-2,4 dimethoxybenzylidene anabaseine (DMXBA) can also enhance auditory sensory gating in animal models. DMXBA is well tolerated in humans and improves several cognitive measures.

CONCLUSION

Alpha-7 nicotinic receptor agonists appear to be reasonable candidates for the treatment of cognitive and perceptual disturbances in schizophrenia.

Potential reduction exposure products and FDA tobacco and regulation: a CNS call to action

A new generation of tobacco harm reduction products is stirring controversy and confusion among healthcare providers. These products, known as "potential reduction exposure products" (PREPs), can be described in terms of reported scientific evidence, as "the good, the bad, and the ugly." On the good side, there is sufficient scientific evidence to support the use of Commit, a new over-the-counter nicotine lozenge PREP, approved for smoking cessation. On the bad side, there is no scientific evidence to support the use of Ariva, another over-the-counter nicotine lozenge PREP, marketed as an alternative to cigarettes when smoking is restricted. On the ugly side, both of these PREPs are nicotine delivery systems with "candy-like" appearances; however, one (Commit) has the Food and Drug Administration (FDA) approval and the other (Ariva) does not. This article provides an overview of PREPs and strategies to help clinical nurse specialists (CNSs) address tobacco harm reduction issues.

High Rates of Sustained Smoking Cessation in Women Hospitalized With Cardiovascular Disease

BACKGROUND

Although men hospitalized with cardiovascular disease (CVD) show high smoking-cessation rates, similar data for women are lacking. We tested the efficacy of smoking-cessation intervention in women hospitalized for CVD.

METHODS AND RESULTS

In this randomized controlled trial conducted from 1996 to 2001, 277 women diagnosed with CVD (mean age 61+/-10 years) were randomly assigned within 1 of 12 San Francisco Bay Area hospitals to a usual-care group (UG; n=135) or intervention group (IG; n=142). Baseline histories were obtained, and interviews to ascertain self-reported smoking status occurred at 6, 12, 24, and 30 months after hospitalization. The UG received strong physician's advice, a self-help pamphlet, and a list of community resources. The IG received strong physician's advice and a nurse-managed cognitive behavioral relapse-prevention intervention at bedside, with telephone contact at intervals after discharge. The groups were similar demographically and had smoked cigarettes for a median of 38 (IG) or 40 (UG) years. Time to resumption of continuous smoking was assessed by Kaplan-Meier analysis, and risk differences between groups were determined. Time smoke-free was significantly greater for the IG than the UG (P=0.038). Point prevalence for nonsmoking at the interviews was somewhat greater for the IG than the UG (P>0.15 at all times).

CONCLUSIONS

Cognitive behavioral intervention resulted in longer average times to resumption of smoking, but in these 2 groups of older women with limited social and financial resources, long-term success rates were similar. Systematic identification of smokers and even the brief intervention afforded the UG yielded a high smoking-cessation rate over time.

Motivating and helping smokers to stop smoking

Smokers try to quit only once every 2 to 3 years and most do not use proven treatments. Repeated, brief, diplomatic advice increases quit rates. Such advice should include a clear request to quit, reinforcing personal risks of smoking and their reversibility, offering solutions to barriers to quitting, and offering treatment. All smokers should be encouraged to use both medications and counseling. Scientifically proven, first-line medications are nicotine gum, inhaler, lozenge, and patch plus the nonnicotine medication bupropion. Proven second-line medications are clonidine, nicotine nasal spray, and nortriptyline. These medications are equally effective and safe and the incidence of dependence is very small. The proven psychosocial therapies are behavioral and supportive therapies. These are as effective as medications and are effective via individual counseling, group, and telephone formats. The writing of this article was supported in part by Senior Scientist Award DA-00450 from the National Institute on Drug Abuse.

Influence of smoking on predictors of vascular disease

Beyond the already well-established strong causative relationship with cancer, smoking increases the risk for vascular disease. Smoking may act directly or adversely influence risk factors contributing to the development of vascular disease. Smoking causes endothelial dysfunction, dyslipidemia (decreased high-density lipoprotein cholesterol levels, hypertriglyceridemia and increased oxidation of low-density lipoprotein cholesterol) and platelet activation leading to a prothrombotic state. Smoking increases emerging risk factors (eg, fibrinogen, homocysteine, and high-sensitivity C-reactive protein) and increases insulin resistance and the risk of developing type 2 diabetes mellitus. The beneficial effects of statins and antioxidants (eg, vitamins C and E, beta-carotene) are counteracted by smoking. Smoking-induced alterations in growth factors, adhesion molecules, and even in genes can accelerate the progression of atherosclerosis. The aim of this review is to consider the adverse consequences of smoking on the factors predisposing to vascular disease and to emphasize the beneficial effects of smoking cessation.

Age-related sensitivity to nicotine for inducible atrial tachycardia and atrial fibrillation

The influence of nicotine in modulating vulnerability to atrial tachycardia and fibrillation (AT/AF) remains ill defined. The isolated hearts of six young (2–3 mo) and six old (22–24 mo) male Fischer 344 rats were Langendorff perfused at 5 ml/min with oxygenated Tyrode solution at 37°C, and the whole heart was also super-fused with warmed oxygenated Tyrode solution at 15 ml/min. Nicotine prolonged the interatrial conduction time and effective refractory period that were significantly ( P < 0.05) higher in the old than in the young rats in a concentration-dependent manner. Nicotine had a biphasic effect on burst atrial pacing-induced AT in both groups, increasing it at 10–30 ng/ml while decreasing it at 50–100 ng/ml ( P < 0.01). Nicotine at 10–100 ng/ml increased burst atrial pacing-induced AF in the young rats but suppressed it in the old rats ( P < 0.01). Optical mapping showed the presence of multiple independent wavefronts during AF and a single periodic large wavefront during AT in both groups. Nicotine, at concentrations found in the blood of smokers (30–85 ng/ml), exerts biphasic effects on inducible AT/AF in young rats and suppresses it in the old rats by causing high degrees of interatrial conduction block.

Persistent use of nicotine replacement therapy: an analysis of actual purchase patterns in a population based sample

BACKGROUND

In 1996, the US Food and Drug Administration (FDA) approved switching nicotine gum and patch from prescription to over-the-counter (OTC) status. Some expressed concerns that broader availability and lack of physician control might increase persistent use of nicotine replacement therapy (NRT)-that is, use beyond the period specified by the FDA approved label.

OBJECTIVE

To estimate the incidence of persistent use of OTC nicotine gum and patch for periods of > 3 months, > or = 6 months, > or = 12 months, and > or 24 months.

DESIGN

Analysis of NRT purchase patterns in data from a population based panel of US households that electronically scanned all household purchases between January 1997 and March 2000.

SUBJECTS

In a national panel of 40,000 US households, 2690 recorded NRT purchases.

RESULTS

Among 805 households that purchased nicotine gum, 2.3% of new purchase incidents led to continuous monthly purchase of gum for > or = 6 months. For nicotine patches (2050 households) the percentage was 0.9%. For both gum and patch, the incidence of persistent purchase dropped below 0.4% by 24 months. Allowing one month gaps within a "continuous" purchase run resulted in increased estimates (for gum: 6.7% for > or = 6 months and 1.0% for > or = 24 months; for patch: 1.7% for > or = 6 months and 0.05% for > or = 24 months).

CONCLUSION

Persistent use of nicotine gum and patch is very rare and has not increased with the transition to OTC use, despite removal of physician oversight.

Smokers' relative risk for aortic aneurysm compared with other smoking-related diseases: a systematic review

OBJECTIVE

Aortic aneurysm has traditionally been considered a manifestation of atherosclerosis, but recent evidence suggests an independent pathogenesis, possibly similar to that of chronic obstructive pulmonary disease (COPD). Further insight into the pathogenesis of aortic aneurysm might be obtained by comparing its association with smoking with that of other smoking-related diseases.

STUDY DESIGN

We conducted a systematic review of studies providing relative risk associated with smoking for both aortic aneurysm and other smoking-related diseases.

RESULTS

We identified 10 eligible studies, which included more than 3 million subjects. The events reported in 9 studies were death from target diseases; the tenth study reported new diagnoses. Relative risk for aortic aneurysm-related events in current smokers was generally 3 to 6, compared with 1 to 2 for coronary artery disease or cerebrovascular disease and 5 to 12 for COPD. For each category of smoking in each study, relative risk associated with smoking was substantially greater for aortic aneurysm than for coronary artery disease or cerebrovascular disease. Our pooled estimates indicate that, in men, the association of ever smoking with aortic aneurysm is 2.5 times greater than the association of ever smoking with coronary artery disease (95% confidence interval [CI], 2.2, 2.8) and 3.5 times greater than the association of ever smoking with cerebrovascular disease (95% CI, 2.4, 5.3), but only 0.56 as great as the association of ever smoking with COPD (95% CI, 0.36, 0.86).

CONCLUSIONS

The difference in magnitude of these associations with smoking is consistent with a non-atherosclerotic cause for aortic aneurysm and/or a stronger effect of smoking on vascular disease in the peripheral arteries.

Smokeless tobacco as a possible risk factor for stroke in men: a nested case-control study

BACKGROUND AND PURPOSE

Snuff and other forms of smokeless tobacco are widely used in some populations. Whereas the detrimental cardiovascular effects of smoking are well documented, possible health hazards associated with the use of smokeless tobacco remain controversial. The purpose of this study was to explore whether the use of snuff, a smokeless tobacco product, increases the risk of stroke in men.

METHODS

In a nested case-control study (1 case and 2 matched controls without cardiovascular disease), information on tobacco habits was collected through population risk factor surveys. During follow-up, first-ever fatal and nonfatal strokes occurring among 25- to 74-year-old participants were identified in a population-based stroke register. The study was restricted to men (276 cases, 551 controls).

RESULTS

The unadjusted odds ratio for stroke in regular cigarette smokers compared with men who never used tobacco was 2.21 (95% CI, 1.29 to 3.79). When never-smoking regular snuff dippers (excluding ex-smokers) were compared with men who never used tobacco, the unadjusted odds ratio was 1.05 (95% CI, 0.37 to 2.94). The odds ratio for never-snuffing smokers versus never-smoking snuff users was 2.90 (95% CI, 0.92 to 9.1). After adjustment for multiple cardiovascular risk factors, the odds ratio for having a stroke was 1.74 (95% CI, 0.85 to 3.54) in regular smokers and 0.87 (95% CI, 0.41 to 1.83) in regular snuff users.

CONCLUSIONS

Whereas regular smoking doubles the risk of stroke in men, snuff use is not associated with any apparent excess risk. Chemical moieties produced by burning tobacco are probably the most important contributors to smokers' excess risk of atherothrombotic disease, including stroke.

Advances in the management of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible airflow limitation with extreme economic and social burden. It is estimated that over the next two decades, it will become the 5(th) most prevalent disease and the 3(rd) most common cause of death in the world. A better understanding of the pathogenesis of airway inflammation and alveolar destruction allows for the development of new therapeutic targets. Tobacco smoking is the most important risk factor in the development of COPD, thus making smoking cessation of the outermost importance. This article provides a critical review of present therapy for COPD. In addition to conventional treatment (bronchodilators, corticosteroids and antibiotics) and smoking cessation therapies, novel approaches with potential benefit are discussed.

Impact of messages on concomitant use of nicotine replacement therapy and cigarettes: a randomized trial on the Internet

AIMS

To assess the impact of messages recommending the concomitant use of nicotine replacement therapy (NRT) and cigarettes on smokers' intention to quit smoking.

DESIGN

Randomized trial.

SETTING

Internet.

PARTICIPANTS

A total of 2027 people who answered an e-mail sent to 9074 current and former smokers recruited on a smoking cessation website.

INTERVENTION

Participants were divided randomly into four groups, each of which received a unique message (in French) by e-mail. The 'control' message said that nicotine replacement therapy (NRT) attenuates withdrawal symptoms in smokers who want to quit. The 'temporary abstinence' message added that NRT can also be used by current smokers to manage smoke-free situations. The 'reduction' message indicated that NRT can be used by current smokers who do not want to quit but want to smoke fewer cigarettes. The 'side-effects' message discouraged concomitant use of NRT and cigarettes.

MEASUREMENTS

Perceived impact of these messages on motivation to quit smoking.

FINDINGS

The e-mail was answered by 2027 people (25% of 8124 valid addresses). Smokers who received the 'reduction' message were slightly more likely than controls to report that this message increased their motivation to quit (66% versus 60%, P = 0.02). In contrast, smokers who received the 'side-effects' message were less likely than controls to report that this message increased their motivation (45% versus 60%, P < 0.001). The 'temporary abstinence' message had no detectable impact on motivation to quit.

CONCLUSIONS

Among smokers recruited via a smoking cessation website, messages encouraging concomitant use of NRT and cigarettes may have either no effect or a positive effect on motivation to quit smoking.

Implications of cigarette smoking for the management of patients with acute coronary syndromes

Smokers differ from nonsmokers in the way they present with acute coronary syndromes and in how they respond to treatment. Although smoking increases the risk of a coronary event and accelerates the progression of established atherosclerosis, paradoxically, smokers have better short-term survival after an acute myocardial infarction, mainly because they are younger and have more favorable coronary anatomy. Thrombolysis appears to be a better treatment in smokers than in nonsmokers, probably because thrombosis plays a more important role in the pathogenesis of acute coronary events in smokers. Patients who continue to smoke after angioplasty or bypass surgery have a worse outcome than nonsmokers or quitters. The 2.5- to 3-fold increase in risk for myocardial infarction or stroke in smokers compared with nonsmokers decreases exponentially after smoking cessation. By 4 years the risk is only slightly higher than the risk of a subject who never smoked.

Estimating the health consequences of replacing cigarettes with nicotine inhalers

BACKGROUND

A fast acting, clean nicotine delivery system might substantially displace cigarettes. Public health consequences would depend on the subsequent prevalence of nicotine use, hazards of delivery systems, and intrinsic hazards of nicotine.

METHODS

A spreadsheet program, DEMANDS, estimates differences in expected mortality, adjusted for nicotine delivery system features and prevalence of nicotine use, by extending the data and methods of the SAMMEC 3 software from the US Centers for Disease Control and Prevention. The user estimates disease risks attributable to nicotine, other smoke components, and risk factors that coexist with smoking. The public health consequences of a widely used clean nicotine inhaler replacing cigarettes were compared to historical observations and public health goals, using four different risk attribution scenarios and nicotine use prevalence from 0-100%.

MAIN OUTCOME MEASURES

Changes in years of potential life before age 85 (YPL85).

RESULTS

If nicotine accounts for less than a third of smokers' excess risk of SAMMEC diseases, as it most likely does, then even with very widespread use of clean nicotine DEMANDS predicts public health gains, relative to current tobacco use. Public health benefits accruing from a widely used clean nicotine inhaler probably equal or exceed the benefits of achieving Healthy People 2010 goals.

CONCLUSIONS

Clean nicotine inhalers might improve public health as much as any feasible tobacco control effort. Although the relevant risk estimates are somewhat uncertain, partial nicotine deregulation deserves consideration as part of a broad tobacco control policy.

The effects of tobacco smoke on the homocysteine level--a risk factor of atherosclerosis

Homocysteine may promote atherogenesis and thrombogenesis. There is evidence from case - control and cross-sectional cohort studies that there is a positive association between plasma homocysteine levels and coronary artery disease, cerebrovascular disease and peripheral vascular disease. There is also some evidence that certain life-style factors such as cigarette smoking may affect homocysteine levels. In this work is presented a review of recent opinion about the influence of tobacco smoking on homocysteine levels.

Hospital- and clinic-based smoking cessation interventions for smokers with cardiovascular disease

Cigarette smoking is the leading preventable cause of death in the United States and a major risk factor for cardiovascular disease (CVD). Large observational epidemiologic studies conducted in diverse populations have demonstrated a strong association between smoking and CVD morbidity and mortality. Observational epidemiologic studies have also demonstrated a substantial benefit of smoking cessation on cardiovascular morbidity and mortality. Smoking cessation after myocardial infarction reduces subsequent cardiovascular mortality by nearly 50%. Therefore, the use of effective strategies to reduce the prevalence of tobacco use is a high priority for both the primary and secondary prevention of CVD. Effective smoking cessation interventions have been identified in randomized controlled trials in the general population of smokers. These methods, which include behavioral counseling and pharmacotherapy, are incorporated into clinical practice guidelines for physicians in the United States and Great Britain. A smaller but still substantial body of evidence demonstrates the efficacy of these interventions in hospital- and clinic-based settings for smokers with CVD. This evidence is sufficient to support the routine implementation of these smoking cessation methods in inpatient and outpatient settings for smokers with CVD.

Safety issues in pharmacotherapy for smoking in patients with cardiovascular disease

Twenty percent of patients with cardiovascular disease smoke, and smoking cessation results in a dramatic decline in the relative risk of future cardiovascular events. Questions regarding the safety of nicotine-replacement therapy and bupropion SR for smoking cessation in patients with cardiovascular disease have arisen, in particular because of potential hemodynamic effects of these agents. There have been several randomized, controlled, clinical trials testing the safety of transdermal nicotine in patients with cardiovascular disease that failed to show an increased risk for cardiac events in active treatment conditions compared with placebo. Efficacy trials conducted in other patient populations also support the safety of nicotine-replacement use in cardiac disease patients. To date there is one randomized controlled trial to test bupropion for smoking cessation conducted in this population. Studies to test the efficacy of bupropion for smoking cessation and depression suggest it is safe to use in cardiac disease patients despite recent case reports of adverse events associated with bupropion use. Nicotine-replacement therapy and bupropion significantly increase long-term smoking cessation rates, and the benefits of cessation exceed the risks for pharmacotherapy in patients with cardiovascular disease.

Smokeless tobacco and cardiovascular disease

Various forms of smokeless tobacco (mainly snuff and chewing tobacco) cause an immediate increase in heart rate and blood pressure, but regular users of smokeless tobacco do not have permanent changes of heart rate or blood pressure when not exposed to tobacco. Cardiac output during workload and maximal working capacity are unaffected. Users of smokeless tobacco usually do not have the biochemical stigmata that regular smokers have. Thus, the scientific literature suggests that they are similar to non-tobacco users in terms of levels of hemoglobin/hematocrit, leukocytes, antioxidant vitamins, fibrinogen, components of the fibrinolytic system, C-reactive protein, and thromboxane A2 production. Two studies have found that snuff users, as opposed to smokers, do not have increased intima-media thickness or atherosclerotic lesions when investigated by ultrasound. Results on the risk for myocardial infarction have provided conflicting evidence, 2 case-control studies showing the same risks as in non-tobacco users and one cohort study showing an increased risk for cardiovascular death. In all, the use of smokeless tobacco (with snuff being the most studied variant) involves a much lower risk for adverse cardiovascular effects than smoking does. Whether or not the apparent risk reduction is a useful strategy to help inveterate smokers to quit is a matter of debate, as are the public health effects of a high prevalence of snuff use in some populations.

Nicotine inhibits cardiac apoptosis induced by lipopolysaccharide in rats

OBJECTIVES

Apoptosis develops in several heart diseases, but the therapeutic options are limited. It was hypothesized that nicotine, which inhibits apoptosis in several cells, inhibits cardiac apoptosis induced by lipopolysaccharide (LPS).

BACKGROUND

Over-the-counter nicotine produces sustained levels (10 to 25 ng/ml) that may be antiapoptotic. Low levels of LPS induce apoptosis by activating tissue renin-angiotensin to stimulate angiotensin II, type 1 (AT(1)) receptors in cardiac myocytes.

METHODS

Adult Sprague Dawley rats were pretreated with nicotine (6 mg/kg/day) or saline for seven to ten days (miniosmotic pumps). The LPS (1 mg/kg) was injected intravenously. Toll-like receptor 4 (TLR4) and angiotensinogen messenger ribonucleic acid (mRNA) were measured in the heart after 0, 4, 8, 16, and 24 h. Cardiac apoptosis was measured by terminal deoxy-nucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining after 24 h. In vitro effects of LPS (10 ng/ml, 24 h) were studied in cardiac myocytes isolated from rats pretreated with nicotine for 7 to 10 days, or after pre-exposing myocytes to nicotine (15 ng/ml) for 1, 4, 16, or 24 h.

RESULTS

Neither nicotine nor LPS affected systolic blood pressure. The LPS increased cardiac apoptosis after 24 h in saline-treated, but not nicotine-treated rats, despite similar increases in cardiac TLR4 and angiotensinogen mRNA over 8 to 16 h. The LPS-induced apoptosis was blocked by pre-exposing myocytes to nicotine for 4 to 24 h (partial inhibition after 1 h). Nicotine did not inhibit apoptosis induced by angiotensin II (100 nM, 24 h).

CONCLUSIONS

Therapeutic levels of nicotine inhibit LPS-induced cardiac apoptosis. This occurs after LPS increases TLR4 and angiotensinogen mRNA, but proximal to AT(1) receptor activation. Nicotine may be a novel inhibitor of cardiac apoptosis in conditions associated with circulating LPS (e.g., decompensated heart failure, acute and chronic infections).

Central role of fibroblast alpha3 nicotinic acetylcholine receptor in mediating cutaneous effects of nicotine

Smoking is associated with aberrant cutaneous tissue remodeling, such as precocious skin aging and impaired wound healing. The mechanism is not fully understood. Dermal fibroblasts (DF) are the primary cellular component of the dermis and may provide a target for pathobiologic effects of tobacco products. The purpose of this study was to characterize a mechanism of nicotine (Nic) effects on the growth and tissue remodeling function of DF. We hypothesized that the effects of Nic on DF result from its binding to specific nicotinic acetylcholine receptors (nAChRs) expressed by these cells and that downstream signaling from the receptors alters normal cell functioning, leading to changes in skin homeostasis. Using RT-PCR and Western blotting, we found that a 24-hour exposure of human DF to 10 micro M Nic causes a 1.9- to 28-fold increase of the mRNA and protein levels of the cell cycle regulators p21, cyclin D1, Ki-67, and PCNA and a 1.7- to 2-fold increase of the apoptosis regulators Bcl-2 and caspase 3. Nic exposure also up-regulated expression of the dermal matrix proteins collagen type Ialpha1 and elastin as well as matrix metalloproteinase-1. Mecamylamine (Mec), the specific antagonist of nAChRs, abolished Nic-induced alterations, indicating that they resulted from a pharmacologic stimulation of nAChRs expressed by DF. To establish the relevance of these findings to a specific nicotinergic pathway, we studied human DF transfected with anti-alpha3 antisense oligonucleotides and murine DF from alpha3 nAChR knockout mice. In both cases, lack of alpha3 was associated with alterations in fibroblast growth and function that were opposite to those observed in DF treated with Nic, suggesting that the nicotinic effects on DF were mostly mediated by alpha3 nAChR. In addition to alpha3, the nAChR subunits detected in human DF were alpha5, alpha7, beta2, and beta4. The exposure of DF to Nic altered the relative amounts of each of these subunits, leading to reciprocal changes in [(3)H]epibatidine-binding kinetics. Thus, some of the pathobiologic effects of tobacco products on extracellular matrix turnover in the skin may stem from Nic-induced alterations in the physiologic control of the unfolding of the genetically determined program of growth and the tissue remodeling function of DF as well as alterations in the structure and function of fibroblast nAChRs.

Smoking cessation for patients with cardiovascular disease: what is the best approach?

Tobacco use remains the major preventable cause of early mortality and morbidity in the US and is a major risk factor for cardiovascular disease (CVD). Quitting smoking rapidly reduces the risk of cardiovascular events. In this review, we identify and discuss best approaches to assist smoking cessation among patients with CVD. Establishing office systems that reliably identify smokers to healthcare providers is an essential first step. Once the patient is identified as a smoker, providers should inquire about their willingness to quit and advise them to quit or provide motivation to get ready to make a quit attempt. Behavioral (counseling) and pharmacologic (nicotine replacement and non-nicotine medications) treatments double or triple long-term cessation rates and should be offered in combination to all patients with CVD who use tobacco. More intensive behavioral therapy is more effective and should be delivered when possible. The choice of pharmacotherapy will depend upon the clinical history of the patient and patient preference. Nicotine replacement and sustained release bupropion (bupropion SR) are first-line treatments for smoking cessation. Nicotine patches have been studied extensively in patients with stable CVD and have been shown to be safe. Bupropion SR has relatively few cardiovascular adverse effects and may be especially useful for patients with CVD; its safety is currently being studied. Special consideration is needed for hospitalized patients with acute coronary syndromes (e.g. myocardial infarction and unstable angina). The safety of pharmacotherapy in the acute setting is not yet established. Behavioral interventions, however, are very effective and should be delivered to all hospitalized smokers. Finally, it is important to create a clinical environment that is supportive of treating patients with tobacco dependence. Simple changes in office and hospital routines and procedures (routine screening to identify smokers, prompts to encourage intervention and links to more intensive tobacco dependence treatment programs) will substantially improve the identification, treatment, and outcomes of patients with CVD who use tobacco.

[Smoking cessation in coronary patients]

Smoking is one of the main risk factors for coronary artery disease and its complications, including sudden death. In smokers, smoking cessation is associated with improved 5-year outcome. Consequently, smoking cessation should be one of the main goals of the clinician in patients hospitalized for a coronary event. Any health professional has the capacity to deliver a simple message: "do you smoke?" and "are you willing to quit?". Such simple questions have a positive impact on the smoker who knows he has coronary artery disease. In addition nicotine substitutes and bupropion are particularly useful to help the patient: their efficacy has been demonstrated in several well-conducted studies. Last, treating tobacco smoking requires long-term follow-up of the patient who will be asked to consult regularly to this purpose.

Women's Initiative for Nonsmoking (WINS V): under-use of nicotine replacement therapy

OBJECTIVE

The purpose of this study was to assess the use of nicotine replacement therapy (NRT) in a nurse-managed smoking cessation program.

DESIGN

A cohort design nested within the WINS randomized clinical trial was used with follow-up at 2, 7, 21, 28, and 90 days.

SETTING

The study took place in 10 hospitals in the San Francisco Bay Area.

SUBJECTS

Participants included 142 women hospitalized with cardiovascular disease (CVD).

OUTCOME MEASURE

The outcome measure was the use of NRT after having been assessed as eligible for its use.

INTERVENTION

NRT was used as an adjunct in the behavioral intervention protocol. NRT was recommended during the hospital intervention and during the 90-day outpatient phase.

RESULTS

Of 142 women in the intervention group, 127 met the criteria for NRT use. During the 5 follow-up assessments, the reported NRT use ranged from 9% to 22%.

CONCLUSION

A low NRT use rate among women with CVD is evident. The results suggest that future research about NRT myths pertaining to women is needed. Nurses can help patients dispel these myths and prevent smoking relapse in women with CVD.

Tobacco smoking as a chronic disease: notes on prevention and treatment

Tobacco use represents a rare confluence of interesting circumstances. Elements of inheritable risk combine with powerful neuropharmacology and a ubiquitous environmental exposure and result in an epidemic that claims over 430,000 lives and costs us over $100 billion annually. It is the single most important remediable public health problem in the United States. Most smokers want to quit smoking and a simple advice from a physician can increase the likelihood of doing so. Moreover, there are a number of pharmacologic and behavioral therapies that are proven to be effective in smoking cessation. Yet, there is an apparent reluctance among physicians to address smoking cessation, perhaps due to a sense of frustration or low self-efficacy. Physicians play an important role in smoking cessation, and intensive interventions are necessary to improve their participation and efficacy. Teaching practical smoking cessation techniques within medical school curricula, with an opportunity for standardized practice and self-evaluation, may be an effective strategy to improve physician practice in this area. Since most smokers try their first cigarette before the age of 18, and youth smoking is on the rise, targeted interventions aimed at preventing initiation and encouraging cessation of smoking among youth are needed. For all tobacco users, a better understanding of the pharmacology and physiology of nicotine addiction may translate into targeted and individualized treatment and prevention strategies, which may improve success rates dramatically. To better control this epidemic, and to meet the nation's public health goals for the year 2010 [145], local tobacco control interventions need to be multifaceted and well integrated into regional and national efforts [146]. Because of the physician's unique societal role with respect to tobacco, doctors may indeed find it possible to impact public opinion and significantly reduce the toll of tobacco by acting at the public health and public policy levels [147]. Those interested in engaging in the public health debate can do more than relay facts about tobacco and health. Involvement in tobacco-control issues provides the opportunity to impact the environmental influences promoting smoking among patients, and is likely to be synergistic with efforts to help smokers quit within the office. Physicians who take steps to engage in local public health initiatives are likely to magnify the effects of their efforts at the bedside [148, 149].

Cardiovascular effects of nasal and transdermal nicotine and cigarette smoking

The purpose of this study was to compare circadian blood pressure and heart rate patterns and other cardiovascular effects of nicotine delivered rapidly (via nasal spray, NNS), slowly (transdermal nicotine, TDN), by cigarette smoking (rapid delivery of nicotine plus other smoke toxins), and placebo NNS. Twelve healthy cigarette smokers were studied on a research ward when they smoked cigarettes (16 per day) or used TDN (15 mg/16 h), NNS (24 1-mg doses per day), or placebo NNS, each for 5 days. There were no significant differences in systolic blood pressure, but diastolic blood pressure was slightly increased during cigarette smoking. Plasma epinephrine, beta-thromboglobulin, and fibrinogen levels were higher during cigarette smoking than with TDN. For most measurements, NNS values were intermediate between and not significantly different from those of cigarette smoking and TDN. We conclude that, at recommended doses, TDN and NNS have fewer effects on biomarkers of cardiovascular risk than does cigarette smoking.

Differential rate responses to nicotine in rat heart: evidence for two classes of nicotinic receptors

Nicotinic acetylcholine receptors are pentameric, typically being composed of two or more different subunits. To investigate which receptor subtypes are active in the heart, we initiated a series of experiments using an isolated perfused rat heart (Langendorff) preparation. Nicotine administration (100 microM) caused a brief decrease (-7 +/- 2%) followed by a much larger increase (17 +/- 5%) in heart rate that slowly returned to baseline within 10 to 15 min. The nicotine-induced decrease in heart rate could be abolished by an alpha7-specific antagonist, alpha-bungarotoxin (100 nM). In contrast, the nicotine-induced increase in heart rate persisted in the presence of alpha-bungarotoxin. These results suggest that the nicotinic acetylcholine receptors (nAChRs) that mediate the initial decrease in heart rate probably contain alpha7 subunits, whereas those that mediate the increase in heart rate probably do not contain alpha7 subunits. To investigate which subunits may contribute to the nicotine-induced increase in heart rate, we repeated our experiments with cytisine, an agonist at nAChRs that contain beta4 subunits. The cytisine results were similar to those obtained with nicotine, thereby suggesting that the nAChRs on sympathetic nerve terminals in the heart probably contain beta4 subunits. Thus, the results of this study show that pharmacologically distinct nAChRs are responsible for the differential effects of nicotine on heart rate. More specifically, our results suggest that alpha7 subunits participate in the initial nicotine-induced heart rate decrease, whereas beta4 subunits help to mediate the subsequent nicotine-induced rise in heart rate.

Interventions for treatment-resistant smokers

We can understand resistance to treatment in smokers in two ways. First, when there is no awareness that smoking can be responsible for a physical disease, e.g., chronic obstructive lung disease or a dependence disorder. Second, when smokers actually seek treatment but fail to respond positively. The first kind-resistance related to lack of awareness-may not be so common in adult US smokers, but is more common among young smokers. Information is crucial to increase awareness. However, such information must be presented in such a way that smokers respond to it. Whether a smoker takes action will also depend on what options and choices are available. Encouraging abrupt cessation as the only option is unlikely to motivate the smokers who have tried to quit many times and failed and those who do not want to give up completely. Alternatives such as quitting gradually-even harm-minimization-should be considered. Hopefully, taking some control over smoking with the help of, for example, nicotine replacement can increase self-efficacy and motivation to quit. For those who find it impossible to quit, harm-minimization procedures should definitely be invoked.

Treating tobacco use and dependence: an evidence-based clinical practice guideline for tobacco cessation

The prevention of tobacco-related morbidity and mortality through smoking cessation intervention is among the most vital missions of the chest clinician. This article summarizes the major findings and clinical recommendations of the US Department of Health and Human Services/Public Health Service Guideline, Treating Tobacco Use and Dependence, which is a comprehensive, evidence-based blueprint for smoking cessation. By becoming fluent in the clinical interventions and by implementing the simple institutional changes described in this article and in the guideline, chest clinicians can more effectively intervene with their patients who smoke.